Helping out: short tasks

Would you like to help out at a PR, differently from reviewing? Here are some ideas:

take a look at PRs with just some mathlib-infrastructure-related CI failure: unless it's an infrastructure PR, these are spurious/not the PRs fault. If the failure is spurious, commenting to this effect can be helpful.
take a look at PRs labelled help-wanted or please-adopt
If the author hasn't noticed, you can ask in a PR which just has a merge conflict, but would be reviewable otherwise. (Remember, that most contributors to mathlib are volunteers, contribute in their free time and often have other commitments — and that real-life events can happen!)
check if any 'stale' PR by a new contributor benefits from support, such as help with failing CI or providing feedback on the code
check if any 'stale' delegated PR benefits from support, such as by fixing merge conflicts (but be sure to ask first; the PR author might simply be very busy)

This dashboard was last updated on: April 22, 2026 at 15:17 UTC

PRs with just failing CI, but only often-spurious jobs

Number	Author	Title	Description	Labels	+/-	Modified files (first 100)	📝	💬	All users who commented or reviewed	Assignee(s)	Updated	Last status change	total time in review
28803	astrainfinita author:astrainfinita	refactor: unbundle algebra from `ENormed*`	Further speed up the search in the algebraic typeclass hierarchy by avoiding searching for `TopologicalSpace`. This PR continues the work from #23961. - Change `ESeminormed(Add)Monoid` and `ENormed(Add)Monoid` so they no longer carry algebraic data. - Deprecate `ESeminormed(Add)CommMonoid` and `ENormed(Add)CommMonoid` in favor of `ESeminormed(Add)Monoid` and `ENormed(Add)Monoid` with a commutative algebraic typeclass. \|Old\|New\| \|---\|---\| \| `[ESeminormed(Add)(Comm)Monoid E]` \| `[(Add)(Comm)Monoid E] [ESeminormed(Add)Monoid E]` \| \| `[ENormed(Add)(Comm)Monoid]` \| `[(Add)(Comm)Monoid E] [ENormed(Add)Monoid]` \| See [Zulip discussion](https://leanprover.zulipchat.com/#narrow/channel/144837-PR-reviews/topic/.2328803.20refactor.3A.20unbundle.20algebra.20from.20.60ENormed*.60/with/536024350) ------------ - [x] depends on: #28813	t-algebra merge-conflict slow-typeclass-synthesis awaiting-zulip t-analysis label:t-algebra$	80/63	Mathlib/Analysis/CStarAlgebra/CStarMatrix.lean,Mathlib/Analysis/Normed/Group/Basic.lean,Mathlib/Analysis/Normed/Group/Continuity.lean,Mathlib/Analysis/Normed/Group/InfiniteSum.lean,Mathlib/Analysis/NormedSpace/IndicatorFunction.lean,Mathlib/MeasureTheory/Function/L1Space/AEEqFun.lean,Mathlib/MeasureTheory/Function/L1Space/HasFiniteIntegral.lean,Mathlib/MeasureTheory/Function/L1Space/Integrable.lean,Mathlib/MeasureTheory/Function/LocallyIntegrable.lean,Mathlib/MeasureTheory/Function/LpSeminorm/Basic.lean,Mathlib/MeasureTheory/Function/LpSeminorm/CompareExp.lean,Mathlib/MeasureTheory/Function/LpSeminorm/TriangleInequality.lean,Mathlib/MeasureTheory/Integral/IntegrableOn.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral/Basic.lean	14	28	['astrainfinita', 'bryangingechen', 'github-actions', 'grunweg', 'kbuzzard', 'leanprover-bot', 'leanprover-community-mathlib4-bot', 'mathlib-bors', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'sgouezel']	grunweg assignee:grunweg	231-55323 7 months ago	240-6477 240 days ago	0-16864 4 hours
25737	robin-carlier author:robin-carlier	feat(AlgebraicTopology/SimplexCategory/GeneratorsRelations/NormalForms): Normal forms for `P_δ`s	We prove that admissible lists indeed provide a normal form for morphisms of satisfying `P_δ`. To this end, we introduce `standardδ`, a construction that takes a list and turn it into a composition of `δ i`s in `SimplexCategoryGenRel`. We then prove that, thanks to the first simplicial identity, composition on the left corresponds to simplicial insertion in the list. This gives existence of a normal form for every morphism satisfying `P_δ`. For unicity, we introduce an auxiliary function `simplicialEvalδ : (List ℕ) → ℕ → ℕ` and show that for admissible lists, it lifts to `ℕ` the `orderHom` attached to `toSimplexCategory.map standardδ`, and that we can recover elements of the list only by looking at values of this function. Part of a series of PR formalising that `SimplexCategoryGenRel` is equivalent to `SimplexCategory`. --- - [x] depends on: #25736 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) --- This PR continues the work from #21746. Original PR: https://github.com/leanprover-community/mathlib4/pull/21746	t-algebraic-topology delegated t-category-theory	181/2	Mathlib/AlgebraicTopology/SimplexCategory/GeneratorsRelations/NormalForms.lean	1	6	['github-actions', 'joelriou', 'mathlib-bors', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	50-82741 1 month ago	183-82468 183 days ago	0-22511 6 hours
35436	daniel-carranza author:daniel-carranza	feat(CategoryTheory/Monoidal/Closed): Prove the isomorphism of internal hom objects C(x \otimes y, z) and C(y, C(x, z))	Prove the currying-uncurrying isomorphism `C(x \otimes y, z) \iso C(y, C(x, z))` between internal hom objects of a closed monoidal category `C`. --- This result is connected to the infinity-cosmos project, and is used to prove that a closed monoidal category enriched in itself admits all cotensors. ~Line 81 currently contains a one-line proof in tactics mode `exact rfl`. When trying to use `rfl` outside of tactics mode, an error is thrown~ (Fixed, thank you @robin-carlier!). Any help with this (or any other aspect of the formalization) is greatly appreciated! [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-category-theory infinity-cosmos delegated	89/0	Mathlib.lean,Mathlib/CategoryTheory/Monoidal/Closed/InternalCurrying.lean	2	15	['dagurtomas', 'daniel-carranza', 'github-actions', 'joelriou', 'mathlib-bors', 'riccardobrasca', 'robin-carlier']	adamtopaz assignee:adamtopaz	46-73297 1 month ago	54-61436 54 days ago	7-65383 7 days
33466	Shreyas4991 author:Shreyas4991	refactor(Combinatorics/Digraph): add vertex sets	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-combinatorics merge-conflict please-adopt	382/55	Mathlib/Combinatorics/Digraph/Basic.lean,Mathlib/Combinatorics/Digraph/Orientation.lean	2	83	['IvanRenison', 'Shreyas4991', 'SnirBroshi', 'YaelDillies', 'copilot-pull-request-reviewer', 'github-actions', 'mathlib-merge-conflicts', 'mathlib4-merge-conflict-bot', 'vihdzp', 'vlad902']	awainverse assignee:awainverse	38-9029 1 month ago	41-82888 41 days ago	26-3608 26 days
30451	kckennylau author:kckennylau	feat(HomogeneousIdeal): generalize to homogeneous submodule	Continuation of #30437 with permission from @jjaassoonn, which is a continuation of #9820 . The definitions, constructions and theorems in `HomogeneousIdeal.lean` are generalized to homogeneous submodules. Let `R` be a graded ring and `M` be a graded `R`-module. Say an `R`-submodule `N` of `M` is homogeneous if for every `x` in `N`, each projection of `x` to `M_i` is in `N`. None of this file's results depends on the grading on `R`, but we include the grading on `R` for technical reasons. We define the "homogeneous core" of a not necessarily homogeneous submodule N to be the biggest homogeneous submodule contained within N, and the "homogeneous hull" to be the smallest homogeneous submodule that contains N. All definitions/constructions/theorems are then copied for ideals/homogeneous ideals. The motivation of this generalization is graded quotient module. (#18716) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-ring-theory awaiting-author merge-conflict	581/185	Mathlib/Algebra/BigOperators/Finsupp/Basic.lean,Mathlib/Algebra/DirectSum/Basic.lean,Mathlib/Algebra/DirectSum/Decomposition.lean,Mathlib/Algebra/DirectSum/Finsupp.lean,Mathlib/Algebra/Module/GradedModule.lean,Mathlib/AlgebraicGeometry/ProjectiveSpectrum/Basic.lean,Mathlib/AlgebraicGeometry/ProjectiveSpectrum/Scheme.lean,Mathlib/RingTheory/GradedAlgebra/Homogeneous/Ideal.lean,Mathlib/RingTheory/GradedAlgebra/Homogeneous/Submodule.lean,Mathlib/RingTheory/GradedAlgebra/Radical.lean	10	23	['github-actions', 'mariainesdff', 'mathlib-merge-conflicts', 'mathlib4-merge-conflict-bot']	mariainesdff assignee:mariainesdff	28-25872 28 days ago	42-1431 42 days ago	22-55625 22 days
37556	edwin1729 author:edwin1729	feat(Topology/Order): Locale.localePointOfSpacePoint if we have a Scott Topology from an Algebraic DCPO	(3/4) in a series of PRs proving that "Scott Topologies over Algebraic DCPOs are Sober" We prove here that the unit of the adjunction from `TopCat` to `Locale` defined in `Topology/Order/Category/FrameAdjunction.lean` is a surjective mapping, under the following condition: The underlying TopologicalSpace must be a Scott Topology generated with an underlying Algebraic DCPO structure. - [ ] depends on: #37445 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology new-contributor blocked-by-other-PR	393/1	Mathlib.lean,Mathlib/Topology/Order/ScottTopology.lean,Mathlib/Topology/Order/ScottTopologyDCPO.lean,docs/references.bib	4	4	['github-actions', 'mathlib-dependent-issues']	nobody	19-81027 19 days ago	19-81028 19 days ago	0-562 9 minutes
37753	JovanGerb author:JovanGerb	chore(Order/Filter/Basic): use `to_dual` for `≤ᶠ`	Use `to_dual` on lemmas about `EventuallyLE`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-order	19/6	Mathlib/Order/Filter/Basic.lean	1	2	['github-actions', 'vihdzp']	nobody	14-81523 14 days ago	14-85834 14 days ago	14-85247 14 days
37386	gasparattila author:gasparattila	chore: call `dsimp` in the default tactic of `ContinuousLinearMap`	--- This will also reduce the breakage in https://github.com/leanprover-community/mathlib4/pull/35548. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology awaiting-author	33/76	Mathlib/Algebra/Category/ContinuousCohomology/Basic.lean,Mathlib/Analysis/CStarAlgebra/CStarMatrix.lean,Mathlib/Analysis/CStarAlgebra/ContinuousFunctionalCalculus/NonUnital.lean,Mathlib/Analysis/CStarAlgebra/ContinuousFunctionalCalculus/Unital.lean,Mathlib/Analysis/Distribution/DerivNotation.lean,Mathlib/Analysis/Distribution/TestFunction.lean,Mathlib/Analysis/Fourier/Notation.lean,Mathlib/Analysis/InnerProductSpace/PiL2.lean,Mathlib/Analysis/InnerProductSpace/Spectrum.lean,Mathlib/Analysis/Normed/Algebra/Spectrum.lean,Mathlib/Analysis/Normed/Lp/PiLp.lean,Mathlib/Analysis/Normed/Lp/ProdLp.lean,Mathlib/Analysis/Normed/Module/WeakDual.lean,Mathlib/Analysis/RCLike/Basic.lean,Mathlib/Analysis/SpecialFunctions/ContinuousFunctionalCalculus/Rpow/ConjSqrt.lean,Mathlib/MeasureTheory/Function/SimpleFuncDenseLp.lean,Mathlib/MeasureTheory/Measure/FiniteMeasure.lean,Mathlib/NumberTheory/ModularForms/JacobiTheta/TwoVariable.lean,Mathlib/Probability/Distributions/Fernique.lean,Mathlib/Probability/Distributions/Gaussian/IsGaussianProcess/Basic.lean,Mathlib/Probability/Distributions/Gaussian/IsGaussianProcess/Independence.lean,Mathlib/Topology/Algebra/Algebra.lean,Mathlib/Topology/Algebra/GroupCompletion.lean,Mathlib/Topology/Algebra/LinearMapCompletion.lean,Mathlib/Topology/Algebra/Module/Alternating/Topology.lean,Mathlib/Topology/Algebra/Module/LinearMap.lean,Mathlib/Topology/Algebra/Module/LinearMapPiProd.lean,Mathlib/Topology/Algebra/Module/Multilinear/Basic.lean,Mathlib/Topology/Algebra/Module/Multilinear/Topology.lean,Mathlib/Topology/Algebra/Module/Star.lean,Mathlib/Topology/Algebra/Star/LinearMap.lean,Mathlib/Topology/CompactOpen.lean,Mathlib/Topology/Constructions.lean,Mathlib/Topology/ContinuousMap/Algebra.lean,Mathlib/Topology/ContinuousMap/Ideals.lean,Mathlib/Topology/Instances/TrivSqZeroExt.lean	36	15	['gasparattila', 'github-actions', 'j-loreaux', 'leanprover-radar', 'mathlib-bors', 'themathqueen']	j-loreaux assignee:j-loreaux	13-21320 13 days ago	14-78248 14 days ago	5-83997 5 days
38048	gilesgshaw author:gilesgshaw	feat(Topology/EMetricSpace/Defs): add theorems `EMetric.continuous_iff`	Add 8 theorems of the form `EMetric.continuous_iff`, which are exactly analogous to existing theorems of the form `Metric.continuous_iff` --- Thus the API between the following files (already pretty consistent) is now more consistent `Topology.MetricSpace.Pseudo.Defs` for `PseudoMetricSpace` `Topology.EMetricSpace.Defs` for `PseudoEMetricSpace` I have copied the theorems exactly (that is, changing only `[e]dist` and `Pseudo[E]MetricSpace`), however perhaps there will be suggestions to make other changes at this opportunity. (E.g. is it worth making the use of strict implicit parameters more consistent - possibly not?)	new-contributor t-topology	44/0	Mathlib/Topology/EMetricSpace/Defs.lean	1	3	['github-actions']	j-loreaux assignee:j-loreaux	6-50851 6 days ago	7-80945 7 days ago	7-80358 7 days
37938	SamuelSchlesinger author:SamuelSchlesinger	feat(Probability/Posterior): Posterior PMFs and Various Lemmas	Upstreaming the probability lemmas needed in https://github.com/leanprover/cslib/pull/464.	t-measure-probability new-contributor awaiting-author	130/0	Mathlib.lean,Mathlib/Probability/ProbabilityMassFunction/Posterior.lean	2	5	['EtienneC30', 'SamuelSchlesinger', 'github-actions']	RemyDegenne assignee:RemyDegenne	6-12862 6 days ago	6-20619 6 days ago	0-73564 20 hours
34875	banrovegrie author:banrovegrie	feat(LinearAlgebra/Matrix): add Sherman-Morrison formula	Mathlib has the matrix determinant lemma (`det_add_replicateCol_mul_replicateRow` in SchurComplement.lean) but lacked the corresponding inverse formula. This PR fills that gap. - Add `Matrix.inv_add_vecMulVec`: Sherman-Morrison formula for `(A + uv^T)^{-1}` - Add `Matrix.inv_sub_vecMulVec`: subtraction variant - Add `Matrix.isUnit_det_add_vecMulVec`: invertibility under the formula's hypotheses ## Test plan - [x] `lake build` passes - [x] Lines within 100 char limit - [x] All declarations have docstrings Any specific AI usage?: Used Copilot for review purposes.	t-algebra new-contributor awaiting-author label:t-algebra$	135/0	Mathlib.lean,Mathlib/LinearAlgebra/Matrix/ShermanMorrison.lean	2	13	['Xxxjdjdid', 'banrovegrie', 'chrisflav', 'copilot-pull-request-reviewer', 'eric-wieser', 'github-actions', 'wwylele']	chrisflav assignee:chrisflav	5-30095 5 days ago	6-79401 6 days ago	69-2479 69 days
37851	gaetanserre author:gaetanserre	feat(Category/Kernel): `Stoch` is a positive Markov category	Add several `Deterministic` instances for `SFinKer` and `Stoch` associators, unitors, braiding, counit, and comul morphisms. In particular, all isomorphisms in `Stoch` are `Deterministic`. To show that, I created `Kernel.IsDeterministicKernel` that encodes that a kernel is _deterministic_, in the sense of Markov category (see Definition 10.1 of _A synthetic approach to Markov kernels, conditional independence and theorems on sufficient statistics_, Fritz 2020). I then followed the proof of Example 11.25 to show that `Stoch` is a positive Markov category (see `Kernel.parallelComp_id_comp_copy_comp`), inducing that all isomorphisms in `Stoch` are `Deterministic`. - [ ] depends on: #38211 - [ ] depends on: #38212 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-measure-probability t-category-theory blocked-by-other-PR	414/38	Mathlib.lean,Mathlib/CategoryTheory/MarkovCategory/Positive.lean,Mathlib/CategoryTheory/Monoidal/Widesubcategory.lean,Mathlib/Probability/Kernel/Category/SFinKer.lean,Mathlib/Probability/Kernel/Category/Stoch.lean,Mathlib/Probability/Kernel/Composition/KernelLemmas.lean,Mathlib/Probability/Kernel/Deterministic.lean	7	11	['RemyDegenne', 'dagurtomas', 'gaetanserre', 'github-actions', 'joelriou', 'mathlib-dependent-issues']	RemyDegenne assignee:RemyDegenne	3-85009 3 days ago	5-76991 5 days ago	5-68884 5 days
36218	Brian-Nugent author:Brian-Nugent	feat(CategoryTheory): Add exact sequences for Sheaf Cohomology	In this PR, I add the long exact sequence for sheaf cohomology as well as prove that it is functorial. Since sheaf cohomology is defined in terms of `Ext`, this is done using the covariant sequence for `Ext`. --- - [ ] depends on: #34742 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import blocked-by-other-PR t-category-theory	313/3	Mathlib.lean,Mathlib/Algebra/Category/Grp/ForgetCorepresentable.lean,Mathlib/CategoryTheory/Sites/Abelian.lean,Mathlib/CategoryTheory/Sites/SheafCohomology/Basic.lean,Mathlib/CategoryTheory/Sites/SheafCohomology/ExactSequences.lean	5	4	['github-actions', 'mathlib-dependent-issues', 'mathlib-merge-conflicts']	nobody	3-71435 3 days ago	unknown	unknown
38315	sgouezel author:sgouezel	chore: make RingHom.comp implicit_reducible	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra label:t-algebra$	3/1	Mathlib/Algebra/Ring/Hom/Defs.lean	1	5	['github-actions', 'leanprover-radar', 'mathlib-bors', 'sgouezel']	nobody	1-5923 1 day ago	1-5923 1 day ago	1-5336 1 day
38296	mike1729 author:mike1729	feat(MeasureTheory/LpSpace): Isometric embedding L∞ → (L¹)*	For a finite measure `μ` and scalar field `𝕜` (any `RCLike`), adds the isometric `𝕜`-linear embedding `Lp 𝕜 ∞ μ →ₗᵢ[𝕜] StrongDual 𝕜 (Lp 𝕜 1 μ)` given by the pairing `g f ↦ ∫ x, g x * f x ∂μ`. Surjectivity (upgrading to the isometric equivalence `Lp 𝕜 ∞ μ ≃ₗᵢ[𝕜] StrongDual 𝕜 (Lp 𝕜 1 μ)`) is addressed in the follow-up PR: https://github.com/leanprover-community/mathlib4/pull/38295. New declarations: - `Mathlib/MeasureTheory/Function/LpSpace/Dual.lean` (new file): `MeasureTheory.Lp.lInftyL1Pairing`, `norm_le_norm_lpPairing_mul_apply`, `lInftyToL1Dualₗᵢ` (and its `_apply_apply` simp lemma). - `Mathlib/MeasureTheory/Function/LpSpace/Basic.lean`: `MeasureTheory.Lp.ae_norm_le_norm`, `MeasureTheory.Lp.measure_norm_gt_pos_of_lt_norm` (general `L∞` helper lemmas). - `Mathlib/MeasureTheory/Function/Holder.lean`: `ContinuousLinearMap.norm_lpPairing_apply_apply_le`, `norm_lpPairing_apply_le` (Hölder-style operator-norm bounds for `lpPairing`). Future PRs: - generalize to Holder conjugates with `p>1`, - generalize to sigma finite measures. --> [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-measure-probability new-contributor LLM-generated	176/0	Mathlib.lean,Mathlib/MeasureTheory/Function/Holder.lean,Mathlib/MeasureTheory/Function/LpSpace/Basic.lean,Mathlib/MeasureTheory/Function/LpSpace/Dual.lean	4	5	['github-actions', 'kbuzzard', 'mike1729']	kex-y assignee:kex-y	0-21547 5 hours ago	2-1641 2 days ago	2-1054 2 days
37940	BryceT233 author:BryceT233	feat(Algebra/Category): the category of local algebras with a fixed residue field	This is an attempt to design the definitions of base category [[Stacks, 06GC]](https://stacks.math.columbia.edu/tag/06GC) and complete base category in deformation theory. The approach we take is to first introduce a larger category of local algebras with a fixed residue field, then define base category and complete base category to be full subcategories of this larger category via `ObjectProperty`. To be specific: * In `Defs.lean`, we define `LocAlgCat` and `LocAlgCat.Hom` to be the type of objects and morphisms in the category, and provide a universe lift functor. * In `Basic.lean`, we add the basic construction `ofQuot` and `toOfQuot`, which is the quotient of an object in `LocAlgCat` by a proper Ideal. Then we use them to define `infinitesimalNeighborhood` and `specialFiber` for an object in `LocAlgCat`. * In `Cotangent.lean`, we introduce `k`-vector space structures on `CotangentSpace` of objects in `LocAlgCat` and prove the exactness of the conormal sequence for the special fiber. * In `BaseCat.lean`, we define `BaseCat` to be the full subcategory of `LocAlgCat` consisting of Artinian local algebras and introduce the type class of a small extension for morphisms in `BaseCat`. We show that any surjective morphism in `BaseCat` can be factored into a finite composition of small extensions [[Stacks, 06GE]](https://stacks.math.columbia.edu/tag/06GE) This PR is intended to showcase the overall design and architecture, I will split this into smaller PRs once the community reaches a consensus on the design choices. --- - [x] depends on: #36657 - [ ] depends on: #37008 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	blocked-by-other-PR t-algebra label:t-algebra$	1584/0	Mathlib.lean,Mathlib/Algebra/Algebra/Subalgebra/Prod.lean,Mathlib/Algebra/Category/LocAlgCat/BaseCat.lean,Mathlib/Algebra/Category/LocAlgCat/Basic.lean,Mathlib/Algebra/Category/LocAlgCat/Cotangent.lean,Mathlib/Algebra/Category/LocAlgCat/Defs.lean,Mathlib/Algebra/Group/Units/ULift.lean,Mathlib/Algebra/Ring/Subring/Basic.lean,Mathlib/RingTheory/Ideal/Cotangent.lean,Mathlib/RingTheory/Ideal/Maps.lean,Mathlib/RingTheory/LocalRing/LocalSubring.lean,Mathlib/RingTheory/LocalRing/ResidueField/Instances.lean,Mathlib/RingTheory/LocalRing/RingHom/Basic.lean	13	30	['BryceT233', 'Deicyde', 'YaelDillies', 'github-actions', 'mathlib-dependent-issues']	nobody	0-18531 5 hours ago	5-15691 5 days ago	2-27351 2 days
38373	Nicola9Falciola author:Nicola9Falciola	feat (Algebra/FreeAbelianGroup /Finsupp) : The support of non zero element in a freeabeliangroup is non empty	Add the lemma that for a nonzero a : FreeAbelianGroup X the support of it is non empty. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra new-contributor label:t-algebra$	4/0	Mathlib/Algebra/FreeAbelianGroup/Finsupp.lean	1	3	['github-actions']	nobody	0-5883 1 hour ago	0-3884 54 minutes ago	0-3297 54 minutes

PRs looking for help

Number	Author	Title	Description	Labels	+/-	Modified files (first 100)	📝	💬	All users who commented or reviewed	Assignee(s)	Updated	Last status change	total time in review
8961	eric-wieser author:eric-wieser	refactor: use the coinduced topology on ULift	--- - [x] depends on: #8958 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	please-adopt merge-conflict awaiting-author awaiting-CI	46/14	Mathlib/Analysis/Normed/Group/Basic.lean,Mathlib/Topology/Bornology/Constructions.lean,Mathlib/Topology/Constructions.lean	3	6	['eric-wieser', 'github-actions', 'leanprover-community-mathlib4-bot', 'urkud']	nobody	630-25393 1 year ago	unknown	unknown
9642	eric-wieser author:eric-wieser	refactor(Analysis/Normed/{Group/Field}/Basic): Let `extends` generate the repeated fields	New-style structure shenanigans mean that instance constructors randomly complain about a missing field that can be found with `__ : MetricSpace _ := infer_instance`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) I will write a longer PR description for this once CI is happy	WIP merge-conflict awaiting-author help-wanted t-analysis	122/202	Mathlib/Analysis/Calculus/ContDiff/Basic.lean,Mathlib/Analysis/Complex/Basic.lean,Mathlib/Analysis/Matrix.lean,Mathlib/Analysis/Normed/Field/Basic.lean,Mathlib/Analysis/Normed/Group/Basic.lean,Mathlib/Analysis/Normed/Group/Completion.lean,Mathlib/Analysis/Normed/Order/Basic.lean,Mathlib/Analysis/NormedSpace/ProdLp.lean,Mathlib/Analysis/NormedSpace/Star/Matrix.lean,Mathlib/Analysis/NormedSpace/Unitization.lean,Mathlib/Analysis/Quaternion.lean,Mathlib/Geometry/Manifold/Instances/Sphere.lean,Mathlib/InformationTheory/Hamming.lean,Mathlib/MeasureTheory/Measure/Lebesgue/VolumeOfBalls.lean,Mathlib/NumberTheory/NumberField/CanonicalEmbedding.lean,Mathlib/NumberTheory/Padics/PadicIntegers.lean,Mathlib/Topology/ContinuousFunction/Bounded.lean	17	11	['eric-wieser', 'leanprover-bot', 'urkud']	nobody	630-25393 1 year ago	unknown	unknown
6791	eric-wieser author:eric-wieser	refactor: Use flat structures for morphisms	This restores the symmetry we had in Lean3, where we had `MonoidHom.mk f one mul` not `MonoidHom.mk (OneHom.mk f one) mul`, and `f.toFun` wasn't notation for `f.toMulHom.toFun`. The nesting provided by the previous inheritance is useless to us in the face of `MonoidHomClass.toMonoidHom`, which completely eta-expands the structure anyway. We call the class `FunLikeFlatHack._` because this means the field is called `to_` which uses up less space in the goal view than any alternative. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict awaiting-author help-wanted awaiting-CI	174/201	Mathlib/Algebra/Algebra/Equiv.lean,Mathlib/Algebra/Algebra/Hom.lean,Mathlib/Algebra/Category/GroupCat/ZModuleEquivalence.lean,Mathlib/Algebra/Category/GroupWithZeroCat.lean,Mathlib/Algebra/Category/ModuleCat/Presheaf.lean,Mathlib/Algebra/Category/MonCat/Basic.lean,Mathlib/Algebra/Group/Ext.lean,Mathlib/Algebra/Group/Prod.lean,Mathlib/Algebra/Group/UniqueProds.lean,Mathlib/Algebra/Hom/Equiv/Basic.lean,Mathlib/Algebra/Hom/Group/Defs.lean,Mathlib/Algebra/Hom/GroupAction.lean,Mathlib/Algebra/Hom/NonUnitalAlg.lean,Mathlib/Algebra/Hom/Ring/Defs.lean,Mathlib/Algebra/Lie/Basic.lean,Mathlib/Algebra/Module/Equiv.lean,Mathlib/Algebra/Module/LinearMap.lean,Mathlib/Algebra/Order/Hom/Ring.lean,Mathlib/Algebra/Order/Interval.lean,Mathlib/Algebra/Ring/Equiv.lean,Mathlib/Analysis/Normed/Group/SemiNormedGroupCat.lean,Mathlib/Data/FunLike/Basic.lean,Mathlib/Data/Rat/Cast/CharZero.lean,Mathlib/Data/Real/EReal.lean,Mathlib/Data/Real/Sqrt.lean,Mathlib/GroupTheory/FreeAbelianGroup.lean,Mathlib/GroupTheory/MonoidLocalization.lean,Mathlib/LinearAlgebra/Quotient.lean,Mathlib/LinearAlgebra/TensorProduct.lean,Mathlib/RingTheory/RingInvo.lean,Mathlib/Topology/Algebra/Module/Basic.lean,Mathlib/Topology/MetricSpace/Dilation.lean	32	0	[]	nobody	630-25392 1 year ago	unknown	unknown
6931	urkud author:urkud	refactor(Analysis/Normed): use `RingHomIsometric` for `.norm_cast`	--- I don't understand why linter fails. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict help-wanted t-analysis	78/68	Mathlib/Analysis/LocallyConvex/ContinuousOfBounded.lean,Mathlib/Analysis/Normed/Field/Basic.lean,Mathlib/Analysis/Normed/Group/Basic.lean,Mathlib/Analysis/NormedSpace/Basic.lean,Mathlib/Analysis/NormedSpace/Exponential.lean,Mathlib/Analysis/NormedSpace/Spectrum.lean,Mathlib/Analysis/RCLike/Basic.lean,Mathlib/NumberTheory/NumberField/Embeddings.lean	8	0	[]	nobody	630-25392 1 year ago	unknown	unknown
7903	urkud author:urkud	feat: define `UnboundedSpace`	--- The new instances generate some timeouts, and I don't understand why. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict help-wanted t-topology	111/59	Mathlib/Analysis/BoxIntegral/Basic.lean,Mathlib/Analysis/Normed/Module/Basic.lean,Mathlib/Topology/Bornology/Basic.lean,Mathlib/Topology/Bornology/Constructions.lean,Mathlib/Topology/MetricSpace/Bounded.lean,Mathlib/Topology/MetricSpace/GromovHausdorffRealized.lean	6	1	['github-actions']	nobody	623-13369 1 year ago	unknown	unknown
9973	Ruben-VandeVelde author:Ruben-VandeVelde	feat: polynomials formed by lists	From https://github.com/leanprover-community/mathlib/pull/15476 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	please-adopt merge-conflict t-data	311/0	Mathlib.lean,Mathlib/Data/Polynomial/OfList.lean	2	0	[]	nobody	616-18469 1 year ago	unknown	unknown
9444	erdOne author:erdOne	feat: Various instances regarding `𝓞 K`.	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict help-wanted t-number-theory	27/0	Mathlib/NumberTheory/NumberField/Basic.lean,Mathlib/RingTheory/IntegralClosure.lean	2	9	['erdOne', 'leanprover-bot', 'mattrobball', 'riccardobrasca', 'xroblot']	nobody	615-15145 1 year ago	unknown	unknown
20656	Komyyy author:Komyyy	feat(Mathlib/Geometry/Manifold/VectorBundle/Sphere): convert orthogonal smooth `M → 𝕊ⁿ` & `M → ℝⁿ⁺¹` to smooth `M → T𝕊ⁿ`	Current Mathlib has no easy way to define function from a manifold to tangent bundles of sphere: `T𝕊ⁿ`. This PR gives this: `sphereTangentMap`. This convert orthogonal smooth `M → 𝕊ⁿ` & `M → ℝⁿ⁺¹` to smooth `M → T𝕊ⁿ`. I also proved that if `f : M → 𝕊ⁿ` & `g : M → ℝⁿ⁺¹` are smooth then `sphereTangentMap` of `f` & `g` is smooth too. --- ⚠ CAUTION I formalized this in my spare time. I don't have the energy to maintain the PR, but I create this PR so this may helps everyone. The only one thing to do is proof cleanup. TODO: - [x] `contDiff_uncurry_stereoInvFunAux` & `coe_sphere_comp_stereoInvFun` may have to be moved to `Mathlib.Geometry.Manifold.Instances.Sphere`. - [ ] Proof cleanup. Current proof may be redundant and ugly. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	please-adopt merge-conflict t-differential-geometry	246/6	Mathlib.lean,Mathlib/Geometry/Manifold/Instances/Sphere.lean,Mathlib/Geometry/Manifold/VectorBundle/Sphere.lean	3	1	['github-actions']	nobody	461-23169 1 year ago	unknown	unknown
11837	trivial1711 author:trivial1711	feat: completion of a uniform multiplicative group	Multiplicativize `Topology.Algebra.GroupCompletion`. That is, rewrite it in the multiplicative setting and recover the original results using `@[to_additive]`. - Because `@[to_additive]` doesn't work with `noncomputable section` (https://github.com/leanprover/lean4/pull/2610), some instances with `@[to_additive]` need to be explicitly marked with `noncomputable instance`. - One might be tempted to multiplicativize this definition from `Topology.Algebra.GroupCompletion`: ```lean instance [UniformSpace α] [Add α] : Add (Completion α) := ⟨Completion.map₂ (· + ·)⟩ ``` to this: ```lean @[to_additive] instance [UniformSpace α] [Mul α] : Mul (Completion α) := ⟨Completion.map₂ (· * ·)⟩ ``` However, as Eric Wieser pointed out, doing so would create a bad diamond with the definition ```lean instance [UniformSpace α] [TopologicalRing α] [UniformAddGroup α] [Ring α] : Mul (Completion α) := ⟨curry <\| (denseInducing_coe.prod denseInducing_coe).extend ((↑) ∘ uncurry (· * ·))⟩ ``` in `Topology.Algebra.UniformRing`. How should this diamond be resolved? Well, the definition of multiplication that uses `curry <\| (denseInducing_coe.prod denseInducing_coe).extend ((↑) ∘ uncurry (· * ·))` is the "correct" one. For example, it yields the correct result if `α` is `ℚ`, unlike the definition that uses `Completion.map₂ (· * ·)`. (This is because `Completion.map₂` yields junk values if used on a function which is not uniformly continuous. Note, however, that if multiplication on `α` is uniformly continuous, then `Completion.map₂ (· * ·)` and `curry <\| (denseInducing_coe.prod denseInducing_coe).extend ((↑) ∘ uncurry (· * ·))` are propositionally equal.) So, following Eric's suggestion, we remove the definition that uses `Completion.map₂ (· * ·)`, and generalize the other definition to any uniform space with a multiplication operation: ```lean @[to_additive] noncomputable instance [UniformSpace α] [Mul α] : Mul (Completion α) := ⟨curry <\| (denseInducing_coe.prod denseInducing_coe).extend ((↑) ∘ uncurry (· * ·))⟩ ``` This requires slightly modifying some of the proofs in `Topology.Algebra.GroupCompletion`. For example, suppose that `α` is a uniform group. Since we can no longer use `Completion.continuous_map₂`, it becomes more efficient to prove that the multiplication, inversion, and division operations on `Completion α` are uniformly continuous before we prove that `Completion α` is a group. - Previously, `Topology.Algebra.GroupCompletion` had an instance: ```lean instance [UniformSpace α] [Sub α] : Sub (Completion α) := ... ``` Naively multiplicativizing this would yield ```lean @[to_additive] instance [UniformSpace α] [Inv α] : Inv (Completion α) := ... ``` Unfortunately, this would conflict with `Topology.Algebra.UniformField`, which already instantiates `Inv (Completion α)` when `α` is a uniform field. Instead, we use two different `instance` declarations. (If `α` is an additive group, then this instantiates `Neg (Completion α)` twice, and the instances are syntactically equal.) ```lean @[to_additive] noncomputable instance [UniformSpace α] [Group α] : Inv (Completion α) := ... instance [UniformSpace α] [Neg α] : Neg (Completion α) := ... ``` This avoids the bad diamond (because a uniform field can never be a `Group`) while remaining backward compatible. Note that the `@[to_additive]` is necessary here, because it maintains the link between the additive setting and multiplicative setting. We use a similar method to instantiate `Div (Completion α)`. - Some definitions in this file involve a module structure on `α`. We leave these as is and do not attempt to multiplicativize them at all. - The instance of `DistribMulAction` must be multiplicativized to an instance of `MulDistribMulAction` manually. Zulip thread: https://leanprover.zulipchat.com/#narrow/stream/287929-mathlib4/topic/Completion.20of.20a.20uniform.20multiplicative.20group --- # (Small) Issue Recall the following trick that this pull request uses to define inversion and negation on uniform spaces. The idea is that we define negation on the completion of any uniform space that has a negation operation, but we define inversion on only the completion of a uniform space that has the structure of a multiplicative group. We do this to avoid creating a bad diamond with the inversion operation on a uniform field. ```lean @[to_additive] noncomputable instance {α : Type} [UniformSpace α] [Group α] : Inv (Completion α) := ... instance {α : Type} [UniformSpace α] [Neg α] : Neg (Completion α) := ... ``` Now, suppose that we want to prove `coe_inv_of_group` (resp. `coe_neg`), which states that the coercion `α → Completion α` commutes with inversion (resp. negation). In the current version of this pull request, `coe_inv_of_group` (resp. `coe_neg`) only applies to uniform multiplicative (resp. additive) groups. However, we do not use the fact that multiplication (resp. addition) on `α` is uniformly continuous to prove it. We only use the fact that inversion (resp. negation) is continuous. So, what we really want is to have more general statements that look like this: ```lean theorem coe_inv_of_group {α : Type} [UniformSpace α] [Group α] [ContinuousInv α] : ... theorem coe_neg {α : Type} [UniformSpace α] [Neg α] [ContinuousNeg α] : ... ``` Note that `coe_inv_of_group` needs the assumption `[Group α]`, because otherwise inversion is not defined on `Completion α` at all. However, `coe_neg` does not need the analogous assumption `[AdditiveGroup α]`. The question is: If `coe_inv_of_group` and `coe_neg` are written in this more general form, how can we link them using `@[to_additive]`? Here is one option, but it obviously leaves something to be desired. ```lean @[to_additive coe_neg_do_not_use_this_use_the_more_general_version] theorem coe_inv_of_group {α : Type} [UniformSpace α] [Group α] [ContinuousInv α] : ... theorem coe_neg {α : Type} [UniformSpace α] [Neg α] [ContinuousNeg α] : ... ``` Co-authored-by: Eric Wieser --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	WIP t-algebra merge-conflict help-wanted t-topology label:t-algebra$	342/217	Mathlib/Analysis/InnerProductSpace/Completion.lean,Mathlib/Analysis/Normed/Group/HomCompletion.lean,Mathlib/Analysis/Normed/Module/Completion.lean,Mathlib/Topology/Algebra/GroupCompletion.lean,Mathlib/Topology/Algebra/InfiniteSum/GroupCompletion.lean,Mathlib/Topology/Algebra/Nonarchimedean/Completion.lean,Mathlib/Topology/Algebra/UniformField.lean,Mathlib/Topology/Algebra/UniformMulAction.lean,Mathlib/Topology/Algebra/UniformRing.lean	9	14	['eric-wieser', 'github-actions', 'trivial1711']	nobody	446-66990 1 year ago	unknown	unknown
7994	ericrbg author:ericrbg	chore: generalize `LieSubalgebra.mem_map_submodule`	--- Not sure if we should rename to something like `mem_map_iff_mem_map_submodule` or not. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	please-adopt merge-conflict t-algebra label:t-algebra$	16/4	Mathlib/Algebra/Lie/SkewAdjoint.lean,Mathlib/Algebra/Lie/Subalgebra.lean	2	3	['eric-wieser', 'ericrbg']	nobody	354-27068 11 months ago	unknown	unknown
15115	kkytola author:kkytola	feat: Generalize assumptions in liminf and limsup results in ENNReals	In a [review comment](https://github.com/leanprover-community/mathlib4/pull/13938#discussion_r1649744441) it was pointed out that results about liminf and limsup in ENNReal hold under milder assumptions. This PR does the generalization. --- This PR is split off from #13938, where the review comment was made. The changes needed for the suggested generalization were of different kind than the simple PR's content, justifying a separate PR. - [x] depends on: #13938 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-order merge-conflict help-wanted awaiting-author t-topology	215/27	Mathlib/MeasureTheory/Measure/Portmanteau.lean,Mathlib/Order/LiminfLimsup.lean,Mathlib/Topology/Instances/ENNReal.lean	3	8	['Ruben-VandeVelde', 'github-actions', 'grunweg', 'j-loreaux', 'kkytola', 'leanprover-community-mathlib4-bot']	nobody	342-8445 11 months ago	unknown	unknown
12799	jstoobysmith author:jstoobysmith	feat(LinearAlgebra/UnitaryGroup): Add properties of Special Unitary Group	Add properties of the special unitary group, mirroring the properties of found in Algebra/Star/Unitary.lean. In particular, I add an instance of `specialUnitaryGroup` as a `Group`, `Star`, `InvolutiveStar`, and `StarMul`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	please-adopt t-algebra new-contributor merge-conflict awaiting-author label:t-algebra$	78/0	Mathlib/LinearAlgebra/UnitaryGroup.lean	1	8	['chrisflav', 'jcommelin', 'leanprover-community-bot-assistant']	nobody	319-50364 10 months ago	unknown	unknown
22925	ggranberry author:ggranberry	feat(Mathlib/PlaceHolder/ToeplitzHausdorff): Toeplitz-Hausdorff	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	WIP new-contributor will-close-soon awaiting-author help-wanted t-analysis	411/0	Mathlib/PlaceHolder/ToeplitzHausdorff.lean,Mathlib/PlaceHolder/ToeplitzHausdorff_v2.lean	2	11	['faenuccio', 'ggranberry', 'github-actions']	faenuccio assignee:faenuccio	252-15441 8 months ago	unknown	unknown
7300	ah1112 author:ah1112	feat: synthetic geometry	This is adding synthetic geometry using Avigad's axioms and formalizing Euclid Book I, through the Pythagorean theorem. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict awaiting-author help-wanted t-euclidean-geometry	2661/0	Mathlib.lean,Mathlib/Geometry/Synthetic/Avigad/Axioms.lean,Mathlib/Geometry/Synthetic/Avigad/EuclidBookI.lean,Mathlib/Geometry/Synthetic/Avigad/Tactics.lean	4	74	['ah1112', 'alreadydone', 'eric-wieser', 'github-actions', 'leanprover-community-bot-assistant', 'plp127', 'tb65536', 'urkud']	nobody	243-48206 8 months ago	unknown	unknown
26085	grunweg author:grunweg	feat: disjoint unions distribute with products of manifolds	This PR continues the work from #22611. Original PR: https://github.com/leanprover-community/mathlib4/pull/22611	please-adopt WIP t-differential-geometry merge-conflict	75/6	Mathlib/Geometry/Manifold/Diffeomorph.lean,Mathlib/Geometry/Manifold/LocalDiffeomorph.lean	2	3	['github-actions', 'grunweg', 'mathlib4-merge-conflict-bot']	nobody	173-17535 5 months ago	unknown	unknown
5863	eric-wieser author:eric-wieser	feat: add elaborators for concrete matrices	--- - [x] depends on: #5866 - [ ] depends on: #5897 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict help-wanted blocked-by-other-PR t-meta	257/7	Mathlib/Control/Monad/Cont.lean,Mathlib/Data/Matrix/Auto.lean,MathlibTest/matrix_auto.lean	3	8	['eric-wieser', 'github-actions', 'kim-em', 'leanprover-community-bot-assistant', 'mathlib4-merge-conflict-bot']	nobody	154-28238 5 months ago	unknown	unknown
5919	MithicSpirit author:MithicSpirit	feat: implement orthogonality for AffineSubspace	Define `AffineSubspace.orthogonal` and `AffineSubspace.IsOrtho`, as well as develop an API emulating that of `Submodule.orthogonal` and `Submodule.IsOrtho`, respectively. Additionally, provide some relevant lemmas exclusive to affine subspaces, which are mostly to do with the relationship between orthogonality and `AffineSubspace.Parallel`. Closes #5539 --- Still WIP as I need to add more docstrings as well as notations for the new definitions. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	WIP new-contributor merge-conflict help-wanted t-analysis	287/0	Mathlib.lean,Mathlib/Analysis/InnerProductSpace/AffineSubspace.lean	2	7	['MithicSpirit', 'eric-wieser', 'github-actions', 'leanprover-community-bot-assistant', 'mathlib4-merge-conflict-bot']	MithicSpirit assignee:MithicSpirit	154-28237 5 months ago	unknown	unknown
13442	dignissimus author:dignissimus	feat: mabel tactic for multiplicative abelian groups	Mabel tactic for multiplicative abelian groups (#10361) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor merge-conflict modifies-tactic-syntax awaiting-author help-wanted t-meta	439/0	Mathlib.lean,Mathlib/Tactic.lean,Mathlib/Tactic/MAbel.lean,MathlibTest/mabel.lean	4	11	['BoltonBailey', 'dignissimus', 'github-actions', 'joneugster', 'kbuzzard', 'mathlib4-merge-conflict-bot']	joneugster assignee:joneugster	154-27973 5 months ago	unknown	unknown
26398	ChrisHughes24 author:ChrisHughes24	feat(ModelTheory): definable functions	--- Possibly this should be generalized to partial functions. I migrated the PR by hand instead of using the script. - [x] depends on: #20166 - [x] depends on: #20161 - [x] depends on: #20115 - [x] depends on: #20174 - [x] depends on: #20175 - [x] depends on: #21948 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	please-adopt merge-conflict t-logic	618/0	Mathlib.lean,Mathlib/ModelTheory/FunctionalFormula.lean	2	13	['ChrisHughes24', 'github-actions', 'jcommelin', 'kckennylau', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'staroperator']	nobody	154-26849 5 months ago	176-16314 176 days ago	87-74589 87 days
29675	yury-harmonic author:yury-harmonic	feat(Wolstenholme): new file	Co-authored-by: @Aristotle-Harmonic --- I still need to cleanup the proof and write the docs. For now, it's just what the AI generated, forward-ported to the latest Mathlib. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict awaiting-author help-wanted t-data	198/0	Mathlib.lean,Mathlib/Data/Nat/Choose/Wolstenholme.lean	2	4	['github-actions', 'mathlib4-merge-conflict-bot', 'yury-harmonic']	nobody	154-25625 5 months ago	unknown	unknown
6859	MohanadAhmed author:MohanadAhmed	feat: TryLean4Bundle: Windows Bundle Creator	# `TryLean4Bundle`: Windows Bundle Creator A Windows batch script and a CI yml file that create an self extracting archive. The user should 1. just download the archive, 2. double click the archive to expand 3. double click the `RunLean.bat` script in the expanded archive. The script currently downloads 7 dependencies into CI then unpacks them in the appropriate locations and finally packs them back. To try a bundle created using these scripts but from a different repo see (https://github.com/MohanadAhmed/TryLean4Bundle/releases) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	WIP help-wanted CI	114/0	.github/workflows/mk_windows_bundle.yml,scripts/windowsBundle.bat	2	0	[]	nobody	153-85950 5 months ago	unknown	unknown
11800	JADekker author:JADekker	feat: KappaLindelöf spaces	Define KappaLindelöf spaces by following the first one-third of the API for Lindelöf spaces. The remainder will be added in a future PR. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	please-adopt merge-conflict t-topology awaiting-zulip	301/2	Mathlib.lean,Mathlib/Topology/Compactness/KappaLindelof.lean,Mathlib/Topology/Compactness/Lindelof.lean	3	38	['ADedecker', 'JADekker', 'PatrickMassot', 'StevenClontz', 'adomani', 'github-actions', 'grunweg', 'kim-em', 'urkud']	nobody	153-85814 5 months ago	unknown	unknown
12087	JADekker author:JADekker	feat: complete API for K-Lindelöf spaces	--- - [ ] depends on: #11800 (which is now awaiting a design decision) [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	please-adopt merge-conflict t-topology blocked-by-other-PR	789/17	Mathlib.lean,Mathlib/Order/Filter/CardinalInter.lean,Mathlib/Topology/Compactness/KLindelof.lean,Mathlib/Topology/Compactness/Lindelof.lean	4	2	['github-actions', 'leanprover-community-mathlib4-bot']	nobody	153-85807 5 months ago	unknown	unknown
12394	JADekker author:JADekker	feat: define pre-tight and tight measures	Define tight measures (by first defining separable and pre-tight measures). Define some api for all three concepts Prove Ulam's tightness theorem and a strengthened version of this. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	please-adopt merge-conflict awaiting-author t-measure-probability	503/0	Mathlib.lean,Mathlib/MeasureTheory/Measure/Tight.lean	2	34	['EtienneC30', 'JADekker', 'github-actions', 'sgouezel']	nobody	153-85787 5 months ago	unknown	unknown
14686	smorel394 author:smorel394	feat(AlgebraicGeometry/Grassmannian): define the Grassmannian scheme	# The Grassmannian scheme Define the Grassmannian scheme by gluing affine charts. We fix a commutative ring `K`, a free `K`-module of finite type `V` and two natural numbers `r` and `c`. The scheme we define should parametrize surjective `K`-linear maps `V →ₗ[K] (Fin r → K)`, assuming that `V` is of rank `r + c`. We actually define the scheme without assuming the condition on the rank of `V`, but it is empty unless the rank of `V` is `r + c`. Main definitions: * `Grassmannian.glueData K V r c`: the `AlgebraicGeometry.Scheme.GlueData` defining the Grassmannian scheme. * `Grassmannian K V r c`: the Grassmannian scheme, defined as `(Grassmannian.glueData K V r c).glued`. * `Grassmannian.structMorphism K V r c`: the structural morphism from `Grassmannian K V r c` to `Spec K`. # Implementation We use as index type for the charts the type `Basis (Fin (r + c)) K V` (so this is empty unless `V` is free of rank `r + c`). All the charts are the same and equal to the affine space with coordinates indexed by `Fin c × Fin r`, that is, to `Spec (MvPolynomial (Fin c × Fin r) K)`. The idea is that, for `i` in `Basis (Fin (r + c)) K V`, the corresponding chart will parametrize all surjective `K`-linear maps `φ : V →ₗ[K] (Fin r → K)` that become isomorphisms when restricted to the `K`-submodule generated by the first `r` vectors of the basis `i`. To get the point of the chart corresponding to `φ`, we take the matrix of `φ` in the basis `i` of `V` and the canonical basis of `Fin r → K`, we divide it on the right by its top `r × r` square submatrix (which is invertible by assumption), and we taken the botton `c × r` submatrix. This is almost the usual description of the Grassmannian by charts, with three differences: * We consider the Grassmannian parametrizing `r`-dimensional quotients of `V` instead of `r`-dimensional subspaces of `V`, because this is more natural when working over a general ring (or scheme). * In the usual description, we fix a basis of `V` and index the chart by its subsets `I` of cardinality `r`. Here, to avoid making a choice, we instead index charts by the set of bases of `V` and always choose the subset `I` to consist of the first `r` vectors. * Instead of working with `FiniteDimensional.finrank K V - r`, which would cause technical trouble because of the way subtraction works on `ℕ`, we introduce the codimension `c` as an auxiliary variable, and our constructions are only interesting when `r + c` is equal to `FiniteDimensional.finrank K V`. # Why is this a WIP * There a bunch of lemmas in the file `AlgebraicGeometry/Grassmannian/Lemmas.lean` that either should not be necessary or should be put in another PR for some other part of mathlib. * The proofs in `AlgebraicGeometry/Grassmannian/Basic.lean` are probably too complicated, and the names suck. # Notes. This contribution was created as part of the AIM workshop "Formalizing algebraic geometry" in June 2024. --- - [x] depends on: #14711 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	please-adopt WIP workshop-AIM-AG-2024 merge-conflict t-algebraic-geometry	1002/0	Mathlib.lean,Mathlib/AlgebraicGeometry/Grassmannian/Basic.lean,Mathlib/AlgebraicGeometry/Grassmannian/Lemmas.lean	3	15	['erdOne', 'github-actions', 'joelriou', 'leanprover-community-mathlib4-bot', 'smorel394']	nobody	153-85743 5 months ago	unknown	unknown
32095	grunweg author:grunweg	chore: fix some explicitVarOfIff linter errors	Needs a merge, and removing the linter changes... should be re-done and split out! --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	please-adopt WIP merge-conflict	320/146	Mathlib/Analysis/LocallyConvex/Bounded.lean,Mathlib/Analysis/Oscillation.lean,Mathlib/Geometry/Manifold/LocalInvariantProperties.lean,Mathlib/MeasureTheory/Measure/EverywherePos.lean,Mathlib/SetTheory/Ordinal/Topology.lean,Mathlib/Topology/Algebra/Group/Basic.lean,Mathlib/Topology/Algebra/Module/Basic.lean,Mathlib/Topology/Algebra/Monoid.lean,Mathlib/Topology/Bases.lean,Mathlib/Topology/Basic.lean,Mathlib/Topology/Category/TopCat/Basic.lean,Mathlib/Topology/Clopen.lean,Mathlib/Topology/CompactOpen.lean,Mathlib/Topology/Compactness/LocallyCompact.lean,Mathlib/Topology/Constructions.lean,Mathlib/Topology/ContinuousOn.lean,Mathlib/Topology/DenseEmbedding.lean,Mathlib/Topology/Gluing.lean,Mathlib/Topology/Homeomorph.lean,Mathlib/Topology/IndicatorConstPointwise.lean,Mathlib/Topology/Inseparable.lean,Mathlib/Topology/Irreducible.lean,Mathlib/Topology/IsLocalHomeomorph.lean,Mathlib/Topology/LocalAtTarget.lean,Mathlib/Topology/Maps/Basic.lean,Mathlib/Topology/MetricSpace/Isometry.lean,Mathlib/Topology/NoetherianSpace.lean,Mathlib/Topology/Order.lean,Mathlib/Topology/Order/LowerUpperTopology.lean,Mathlib/Topology/Partial.lean,Mathlib/Topology/PartialHomeomorph.lean,Mathlib/Topology/PartitionOfUnity.lean,Mathlib/Topology/QuasiSeparated.lean,Mathlib/Topology/Separation.lean,Mathlib/Topology/TietzeExtension.lean,Mathlib/Topology/UniformSpace/Ascoli.lean,Mathlib/Topology/UniformSpace/Basic.lean,Mathlib/Topology/UniformSpace/Cauchy.lean,Mathlib/Topology/UniformSpace/CompactConvergence.lean,Mathlib/Topology/UniformSpace/Completion.lean,Mathlib/Topology/UniformSpace/Equicontinuity.lean,Mathlib/Topology/UniformSpace/Matrix.lean,Mathlib/Topology/UniformSpace/Pi.lean,Mathlib/Topology/UnitInterval.lean,Mathlib/Topology/UrysohnsBounded.lean,Mathlib/Topology/UrysohnsLemma.lean,Mathlib/Topology/VectorBundle/Basic.lean,lakefile.lean,scripts/run_linter.lean	49	0	[]	nobody	148-12859 4 months ago	unknown	unknown
5934	eric-wieser author:eric-wieser	feat: port Data.Rat.MetaDefs	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) This needs some eyes from people familiar with Qq	merge-conflict help-wanted mathlib-port t-meta	183/0	Mathlib.lean,Mathlib/Data/Rat/MetaDefs.lean,test/rat.lean	3	5	['eric-wieser', 'gebner', 'vihdzp']	nobody	116-73276 3 months ago	unknown	unknown
21344	kbuzzard author:kbuzzard	chore: attempt to avoid diamond in OreLocalization	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	please-adopt t-algebra label:t-algebra$	16/5	Mathlib/RingTheory/OreLocalization/Basic.lean	1	6	['erdOne', 'github-actions', 'kbuzzard']	nobody	107-61964 3 months ago	unknown	unknown
17176	arulandu author:arulandu	feat: integrals and integrability with .re	Lemmas for swapping order of .re and integration/integrability. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict awaiting-author new-contributor t-measure-probability please-adopt	49/0	Mathlib/MeasureTheory/Function/L1Space.lean,Mathlib/MeasureTheory/Integral/IntegrableOn.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral.lean,Mathlib/MeasureTheory/Integral/SetIntegral.lean	4	32	['EtienneC30', 'arulandu', 'github-actions', 'loefflerd']	nobody	106-69379 3 months ago	unknown	unknown
26088	grunweg author:grunweg	chore(Linter/DirectoryDependency): move forbidden directories into a JSON file	This PR continues the work from #25406. Original PR: https://github.com/leanprover-community/mathlib4/pull/25406	please-adopt t-linter merge-conflict	387/19	Mathlib/Tactic/Linter/DirectoryDependency.lean,scripts/README.md,scripts/forbiddenDirs.json	3	5	['Vierkantor', 'github-actions', 'grunweg', 'mathlib4-merge-conflict-bot']	nobody	104-55154 3 months ago	unknown	unknown
24010	grunweg author:grunweg	feat(Counterexamples): a non-negative function, not a.e. zero, with vanishing lowe…	…r Lebesgue integral. Came up in #23707, let's document this while we're at it. --- - [ ] depends on: #20722 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict please-adopt WIP blocked-by-other-PR t-measure-probability	110/0	Counterexamples.lean,Counterexamples/LIntegralZero.lean	2	3	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	104-7609 3 months ago	unknown	unknown
25905	mans0954 author:mans0954	feat(RingTheory/Polynomial/SmallDegreeVieta): polynomial versions of results in Algebra.QuadraticDiscriminant	This PR continues the work from #25605. Original PR: https://github.com/leanprover-community/mathlib4/pull/25605	merge-conflict t-ring-theory please-adopt	77/8	Mathlib/Algebra/Polynomial/Coeff.lean,Mathlib/RingTheory/Polynomial/SmallDegreeVieta.lean	2	47	['chrisflav', 'github-actions', 'kckennylau', 'mans0954', 'mathlib4-merge-conflict-bot', 'ocfnash']	chrisflav assignee:chrisflav	101-58272 3 months ago	228-251 227 days ago	81-61193 81 days
25907	mans0954 author:mans0954	feat: low order roots of unity	This PR continues the work from #25470. Original PR: https://github.com/leanprover-community/mathlib4/pull/25470	t-algebra please-adopt label:t-algebra$	182/0	Mathlib/Algebra/CharP/Invertible.lean,Mathlib/RingTheory/RootsOfUnity/Complex.lean	2	3	['github-actions', 'mans0954', 'urkud']	jcommelin assignee:jcommelin	101-58255 3 months ago	153-71840 153 days ago	115-85002 115 days
26339	mans0954 author:mans0954	feat(Analysis/Normed/Module/WeakDual): Banach Dieudonné Lemma	This PR continues the work from #16316. Original PR: https://github.com/leanprover-community/mathlib4/pull/16316	merge-conflict WIP t-analysis large-import please-adopt	377/3	Mathlib/Analysis/LocallyConvex/AbsConvex.lean,Mathlib/Analysis/LocallyConvex/Polar.lean,Mathlib/Analysis/Normed/Module/WeakDual.lean,Mathlib/Topology/UniformSpace/Cauchy.lean	4	5	['github-actions', 'mans0954', 'mathlib4-merge-conflict-bot']	nobody	101-58233 3 months ago	unknown	unknown
26340	mans0954 author:mans0954	feat(Algebra/Module/NestAlgebra): Nest algebras	This PR continues the work from #18705. Original PR: https://github.com/leanprover-community/mathlib4/pull/18705	merge-conflict t-algebra please-adopt label:t-algebra$	184/0	Mathlib.lean,Mathlib/Algebra/Module/NestAlgebra.lean,Mathlib/Order/Nest.lean,Mathlib/Order/Preorder/Chain.lean,docs/references.bib	5	3	['github-actions', 'mans0954', 'mathlib4-merge-conflict-bot']	nobody	101-58217 3 months ago	unknown	unknown
26341	mans0954 author:mans0954	feat(LinearAlgebra/QuadraticForm/Basis): Free Tensor product of Quadratic Maps	This PR continues the work from #19432. Original PR: https://github.com/leanprover-community/mathlib4/pull/19432	merge-conflict WIP t-algebra large-import please-adopt label:t-algebra$	888/0	Mathlib.lean,Mathlib/Data/Sym/Sym2/Prod.lean,Mathlib/LinearAlgebra/QuadraticForm/Basis.lean	3	3	['github-actions', 'mans0954', 'mathlib4-merge-conflict-bot']	nobody	101-57986 3 months ago	unknown	unknown
26344	mans0954 author:mans0954	feat(Analysis/NormedSpace/MStructure): The component projections on WithLp 1 (α × β) are L-projections	This PR continues the work from #20380. Original PR: https://github.com/leanprover-community/mathlib4/pull/20380	merge-conflict WIP t-analysis file-removed please-adopt	20/1	Mathlib.lean,Mathlib/Analysis/Normed/Lp/MStructure.lean,Mathlib/Analysis/Normed/Lp/ProdLp.lean	3	3	['github-actions', 'mans0954', 'mathlib4-merge-conflict-bot']	nobody	101-52782 3 months ago	unknown	unknown
26347	mans0954 author:mans0954	feat(Data/Finset/RangeDistance): abs_sub_lt_of_mem_finset_range	This PR continues the work from #23161. Original PR: https://github.com/leanprover-community/mathlib4/pull/23161	merge-conflict t-data please-adopt	30/0	Mathlib.lean,Mathlib/Algebra/Order/Group/Unbundled/Abs.lean,Mathlib/Data/Finset/RangeDistance.lean	3	3	['github-actions', 'mans0954', 'mathlib4-merge-conflict-bot']	alreadydone assignee:alreadydone	101-52759 3 months ago	154-26857 154 days ago	142-36931 142 days
26349	mans0954 author:mans0954	feat(Analysis/SpecialFunctions/Trigonometric/Basic): sin and cos of multiples of π / 3	This PR continues the work from #25009. Original PR: https://github.com/leanprover-community/mathlib4/pull/25009	help-wanted t-analysis please-adopt	159/0	Mathlib/Algebra/Order/Monoid/NatCast.lean,Mathlib/Analysis/SpecialFunctions/Trigonometric/Basic.lean,Mathlib/Data/Nat/Cast/Defs.lean,MathlibTest/trigonometry.lean	4	3	['github-actions', 'mans0954', 'themathqueen']	nobody	101-52715 3 months ago	unknown	unknown
26348	mans0954 author:mans0954	feat(Analysis/LocallyConvex/Prime): the prime map	This PR continues the work from #24385. Original PR: https://github.com/leanprover-community/mathlib4/pull/24385	merge-conflict WIP t-analysis please-adopt	125/0	Mathlib.lean,Mathlib/Analysis/LocallyConvex/Prime.lean	2	3	['github-actions', 'mans0954', 'mathlib4-merge-conflict-bot']	nobody	101-52706 3 months ago	unknown	unknown
26983	mans0954 author:mans0954	feat(Order/LatticeElements): distributive, standard and neutral elements of a lattice	Defines distributive, standard and neutral elements of a lattice and gives equivalent conditions. --- - [x] depends on: #26836 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict WIP t-order please-adopt	238/0	Mathlib.lean,Mathlib/Order/Hom/Lattice.lean,Mathlib/Order/LatticeElements.lean	3	5	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	101-52673 3 months ago	198-76930 198 days ago	0-19323 5 hours
29980	mans0954 author:mans0954	refactor(RingTheory/Polynomial/Resultant/Quadratic): Re-implement QuadraticDiscriminant for R[X]	Re-implement `Algebra/QuadraticDiscriminant` for polynomials. [Zulip discussion](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/discriminants.20of.20low.20degree.20polynomials/with/538010519) --- - [ ] depends on: #29981 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict please-adopt	208/0	Mathlib.lean,Mathlib/RingTheory/Polynomial/Resultant/Quadratic.lean	2	4	['JovanGerb', 'github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	JovanGerb assignee:JovanGerb	101-52640 3 months ago	154-25594 154 days ago	41-43711 41 days
29387	mans0954 author:mans0954	feat(Analysis/LocallyConvex/WeakSpace): toWeakSpace_closedAbsConvexHull_eq	The closed absolutely convex hull taken in the weak topology coincides with the closed absolutely convex hull taken in the original topology. --- - [ ] depends on: #29378 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict blocked-by-other-PR t-analysis please-adopt	133/68	Mathlib/Analysis/Convex/Basic.lean,Mathlib/Analysis/LocallyConvex/AbsConvex.lean,Mathlib/Analysis/LocallyConvex/AbsConvexOpen.lean,Mathlib/Analysis/LocallyConvex/BalancedCoreHull.lean,Mathlib/Analysis/LocallyConvex/Basic.lean,Mathlib/Analysis/Normed/Module/Dual.lean	6	5	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	101-52621 3 months ago	unknown	unknown
29378	mans0954 author:mans0954	feat(Analysis/LocallyConvex/AbsConvex): Balanced and AbsConvex sets under linear maps	Provide `Balanced` and `AbsConvex` versions of `Convex.linear_image`, `Convex.linear_preimage` and the `is_linear` equivalents. --- - [ ] depends on: #29342 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-analysis please-adopt	133/68	Mathlib/Analysis/Convex/Basic.lean,Mathlib/Analysis/LocallyConvex/AbsConvex.lean,Mathlib/Analysis/LocallyConvex/AbsConvexOpen.lean,Mathlib/Analysis/LocallyConvex/BalancedCoreHull.lean,Mathlib/Analysis/LocallyConvex/Basic.lean,Mathlib/Analysis/Normed/Module/Dual.lean	6	4	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	101-52461 3 months ago	189-42362 189 days ago	0-14240 3 hours
12934	grunweg author:grunweg	chore: replace more uses of > or ≥ by < or ≤	These were flagged by the linter in https://github.com/leanprover-community/mathlib4/pull/12879: it is easy to simple avoid > or ≥ in hypotheses or haves. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict awaiting-author help-wanted	41/42	Archive/Imo/Imo1962Q1.lean,Archive/Imo/Imo1988Q6.lean,Archive/Imo/Imo1994Q1.lean,Archive/Imo/Imo2005Q3.lean,Archive/Imo/Imo2006Q3.lean,Archive/Imo/Imo2008Q2.lean,Archive/Imo/Imo2008Q3.lean,Archive/Imo/Imo2019Q4.lean,Archive/Sensitivity.lean,Archive/Wiedijk100Theorems/CubingACube.lean,Mathlib/Tactic/Linarith/Datatypes.lean,test/cancel_denoms.lean,test/congr.lean,test/interval_cases.lean,test/observe.lean	15	12	['YaelDillies', 'adomani', 'github-actions', 'grunweg', 'jcommelin', 'urkud']	nobody	100-39687 3 months ago	unknown	unknown
8608	eric-wieser author:eric-wieser	feat: multiplicativize `AddTorsor`	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict WIP t-algebra please-adopt label:t-algebra$	268/199	Mathlib/Algebra/AddTorsor.lean,Mathlib/Algebra/Group/Defs.lean,Mathlib/Data/Set/Pointwise/SMul.lean,Mathlib/Tactic/ToAdditive.lean	4	2	['alreadydone']	nobody	84-53232 2 months ago	unknown	unknown
23042	joneugster author:joneugster	feat(CategoryTheory/Enriched/Limits): add HasConicalLimitsOfSize.shrink	--- Note: I've marked this "WIP" because I'm not yet sure when this will be needed and I'd probably put the PR on the queue once I've created some follow-up needing it. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	WIP t-category-theory infinity-cosmos please-adopt	22/1	Mathlib/CategoryTheory/Enriched/Limits/HasConicalLimits.lean	1	1	['github-actions']	nobody	66-43182 2 months ago	unknown	unknown
23142	joneugster author:joneugster	feat(CategoryTheory/Enriched/Limits): add API for HasConicalLimit	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-author t-category-theory infinity-cosmos please-adopt	52/9	Mathlib/CategoryTheory/Enriched/Limits/HasConicalLimits.lean	1	2	['github-actions', 'joelriou']	nobody	66-43182 2 months ago	unknown	unknown
23145	joneugster author:joneugster	feat(CategoryTheory/Enriched/Limits): add IsConicalLimits	--- - [ ] depends on: #23142 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict blocked-by-other-PR t-category-theory infinity-cosmos please-adopt	221/9	Mathlib.lean,Mathlib/CategoryTheory/Enriched/Limits/HasConicalLimits.lean,Mathlib/CategoryTheory/Enriched/Limits/IsConicalLimit.lean	3	3	['github-actions', 'joelriou', 'mathlib4-dependent-issues-bot']	nobody	66-43181 2 months ago	unknown	unknown
35339	grunweg author:grunweg	feat: "confusing variables" linter	Continuation of #15400. This linter flags variable commands which both update an existing binder annotation and declare new variables: these can yield confusing or misleading error messages (see https://github.com/leanprover/lean4/issues/2789). Instead, these should be split in several variable statements. ------------ Help fixing these errors is welcome! Currently, the linter only catches some cases, when the updated binder is from a previous scope. To make it catch all cases, the linter could insert a section before the variable command and use that scope instead. See [zulip](https://leanprover.zulipchat.com/#narrow/stream/113488-general/topic/Get.20scope.20before.20some.20syntax.20is.20evaluated) [discussions](https://leanprover.zulipchat.com/#narrow/stream/113488-general/topic/Determining.20variable.20binders.20from.20syntax). --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	please-adopt merge-conflict awaiting-CI t-linter	220/9	Cache/Requests.lean,Mathlib/FieldTheory/AbelRuffini.lean,Mathlib/FieldTheory/IntermediateField/Basic.lean,Mathlib/FieldTheory/KummerExtension.lean,Mathlib/LinearAlgebra/CliffordAlgebra/Basic.lean,Mathlib/Tactic/Linter/Lint.lean,Mathlib/Tactic/Linter/Style.lean,MathlibTest/LintStyle.lean	8	0	[]	nobody	66-13552 2 months ago	unknown	unknown
35344	grunweg author:grunweg	feat: lint upon uses of the mono tactic	suggesting to use `gcongr` instead. In general, `mono` is unmaintained, was only partially ported --- and gcongr at this point is more featureful, actively developed and has a nicer user interface. The topic was also discussed [on zulip](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Porting.20note.3A.20Fixing.20up.20.60mono.60/with/445125798). --- TODO: update the linter wording, fix its implementation and wait until tests pass Rebased and migrated version of #25700. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	please-adopt t-linter RFC	4/0	MathlibTest/DeprecatedSyntaxLinter.lean,MathlibTest/Monotonicity.lean	2	2	['github-actions', 'grunweg']	nobody	65-69371 2 months ago	unknown	unknown
8102	miguelmarco author:miguelmarco	feat(Tactic): add `unify_denoms` and `collect_signs` tactics	This PR adds four new tactics: - `unify_denoms` tries to put expressions with several divisions in a form with only one division. In the case of fields, it works similarly to `field_simp`, but if the hypothesis about denominators being nonzero are not present, it assumes them, and leaves them as new goals to prove. In that sense, it is an "unsafe" tactic (but can be useful nevertheless, for example when you can't find which exact hypothesis is missing). It also works with expressions of naturals and Euclidean domains, assuming the corresponding hypothesis about the denominators dividing the numerators. - `unify_denoms!` extends `unify_denoms` to work with (in)equalities, assuming also that the denominators, once in normal form, are positive. - `collect_signs` works similarly with expressions using sums and substractions: it tries to put them in a form of one sum minus other sum. In the case of working with naturals, it assumes that we never substract a bigger number from a smaller one. Both are implemented essentially as a macro that combines several rewriting rules. Some new lemmas with the corresponding rules are added. ---	please-adopt new-contributor merge-conflict modifies-tactic-syntax good first issue t-meta	407/0	Mathlib.lean,Mathlib/Algebra/EuclideanDomain/Basic.lean,Mathlib/Tactic.lean,Mathlib/Tactic/CollectSigns.lean,Mathlib/Tactic/UnifyDenoms.lean,MathlibTest/unify_denoms.lean,scripts/noshake.json	7	55	['Paul-Lez', 'YaelDillies', 'github-actions', 'joneugster', 'kbuzzard', 'mathlib4-merge-conflict-bot', 'miguelmarco']	nobody	54-5093 1 month ago	unknown	unknown
9605	davikrehalt author:davikrehalt	feat(Data/Finset & List): Add Lemmas for Sorting and Filtering	This PR includes several useful lemmas to the Data/Finset and Data/List modules in Lean's mathlib: 1. `toFinset_filter` (List): Shows that filtering commutes with toFinset. 2. `toFinset_is_singleton_implies_replicate` (List): Shows a list with a singleton toFinset is a List.replicate. 3. `filter_sort_commute` (Finset): Sorting and filtering can be interchanged in Finsets. 4. `Sorted.filter` (List): A sorted list stays sorted after filtering. 5. `Sorted.append_largest` (List): Appending the largest element keeps a list sorted. 6. `sort_monotone_map` (Finset): Relates sorting of a Finset after mapping to sorting of a list. 7. `sort_insert_largest` (Finset): Sorting a Finset with an inserted largest element. 8. `sort_range` (Finset): Sorting a range in a Finset equals the corresponding range list. 9. ~~`filter_eval_true` (List): Filtering a list with a predicate always true keeps the list unchanged.~~ 10. ~~`filter_eval_false` (List): Filtering with an always-false predicate gives an empty list.~~ 11. ~~`pairwise_concat` (List): Iff condition for Pairwise relation in concatenated lists (similar to pairwise_join).~~ 12. `list_map_toFinset` (Finset): toFinset commutes with map under injection --- - [x] depends on: #15952 This is my first PR to mathlib, so I'm not too familiar with etiquette's and more specifically there are two proofs in the PR which uses aesop, and I am not sure if it's frowned upon. I kept the aesop in there for now as I couldn't construct very short proofs otherwise. The sort_range function proof was suggested in https://leanprover.zulipchat.com/#narrow/stream/113489-new-members/topic/Computing.20Finset.20sort.20of.20Finset.20range/near/410346731 by Ruben Van de Velde. Thanks for your time for improving this PR.	please-adopt t-data new-contributor merge-conflict awaiting-author	71/0	Mathlib/Data/Finset/Basic.lean,Mathlib/Data/Finset/Image.lean,Mathlib/Data/Finset/Sort.lean,Mathlib/Data/List/Sort.lean	4	30	['YaelDillies', 'davikrehalt', 'eric-wieser', 'github-actions', 'jcommelin', 'urkud', 'vihdzp']	nobody	41-20560 1 month ago	unknown	unknown
29856	mans0954 author:mans0954	feat(Analysis/Normed/Ring/Basic): Add NonUnitalNonAssocSeminormedRing and NonUnitalNonAssocNormedRing	Adds the classes `NonUnitalNonAssocSeminormedRing` and `NonUnitalNonAssocNormedRing` and relaxes the `NonUnitalSeminormedRing` section to `NonUnitalNonAssocSeminormedRing`. Examples of non-unital non-associative normed rings include non-untial JB-algebras and non-unital JB*-algebras. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-analysis please-adopt	110/11	Mathlib/Analysis/Normed/Ring/Basic.lean,MathlibTest/TCSynth.lean	2	15	['github-actions', 'j-loreaux', 'leanprover-bot']	ADedecker and j-loreaux assignee:j-loreaux assignee:ADedecker	40-42845 1 month ago	154-62032 154 days ago	57-10323 57 days
33466	Shreyas4991 author:Shreyas4991	refactor(Combinatorics/Digraph): add vertex sets	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-combinatorics merge-conflict please-adopt	382/55	Mathlib/Combinatorics/Digraph/Basic.lean,Mathlib/Combinatorics/Digraph/Orientation.lean	2	83	['IvanRenison', 'Shreyas4991', 'SnirBroshi', 'YaelDillies', 'copilot-pull-request-reviewer', 'github-actions', 'mathlib-merge-conflicts', 'mathlib4-merge-conflict-bot', 'vihdzp', 'vlad902']	awainverse assignee:awainverse	38-9029 1 month ago	41-82888 41 days ago	26-3608 26 days
22366	kim-em author:kim-em	feat: `check_equalities` tactic for diagnosing defeq problems	The `check_equalities` tactic, which checks the typing of equalities in the goal, reporting discrepancies between the implicit type argument of the equality, and the inferred types of the left and right hand sides, at "instances and reducible" transparency. Reports from this tactic do not necessarily indicate a problem, although typically `simp` should reduce rather than increase the reported discrepancies. `check_equalities` may be useful in diagnosing uses of `erw`.	t-meta please-adopt WIP	123/4	Mathlib.lean,Mathlib/Tactic.lean,Mathlib/Tactic/Basic.lean,Mathlib/Tactic/CategoryTheory/CheckCompositions.lean,Mathlib/Tactic/CheckEqualities.lean,Mathlib/Tactic/Common.lean,MathlibTest/check_equalities.lean	7	21	['adomani', 'b-mehta', 'eric-wieser', 'fpvandoorn', 'github-actions', 'grunweg', 'kim-em', 'mathlib-bors', 'mathlib4-merge-conflict-bot']	adamtopaz assignee:adamtopaz	30-12886 30 days ago	30-12897 30 days ago	16-84211 16 days
20719	gio256 author:gio256	feat(AlgebraicTopology): delaborators for truncated simplicial notations	We add delaborators for the following notations, introduced in #20688: - `⦋m⦌ₙ`, which denotes the `m`-dimensional simplex in the `n`-truncated simplex category. - `X _⦋m⦌ₙ`, which denotes the `m`-th term of an `n`-truncated simplicial object `X`. - `X ^⦋m⦌ₙ`, which denotes the `m`-th term of an `n`-truncated cosimplicial object `X`. If `pp.proofs` is set to `true`, we also pretty-print the proof `p : m ≤ n` for all three notations as `⦋m, p⦌ₙ`, `X _⦋m, p⦌ₙ`, and `X ^⦋m, p⦌ₙ`, respectively. Credit to @kmill for one piece of code and much metaprogramming inspiration. --- - [x] depends on: #20688 - [x] depends on: #23018 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-algebraic-topology infinity-cosmos t-meta please-adopt will-close-soon	525/33	Mathlib.lean,Mathlib/AlgebraicTopology/SimplexCategory/Basic.lean,Mathlib/AlgebraicTopology/SimplexCategory/Defs.lean,Mathlib/AlgebraicTopology/SimplicialObject/Basic.lean,Mathlib/Tactic.lean,Mathlib/Tactic/SimplexCategory.lean,Mathlib/Util/Superscript.lean,MathlibTest/SimplexCategory.lean,MathlibTest/SimplicialObject.lean,MathlibTest/superscript.lean,scripts/noshake.json	11	24	['eric-wieser', 'gio256', 'github-actions', 'joneugster', 'kim-em', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	26-18552 26 days ago	unknown	unknown
21476	grunweg author:grunweg	feat(lint-style): enable running on downstream projects	Enable lint-style to run on downstream projects, by making the following modifications: - allow passing an explicit list of libraries to lint: if nothing is passed, it lints `Mathlib`, `Archive` and `Counterexamples` (as before); otherwise, it lints precisely the passed modules - only check init imports, undocumented scripts and the errors from `lint-style.py` when linting Mathlib - make the style exceptions file configurable and optional: using the `nolints-file` flag, the exceptions file can be configured. If the flag is omitted, we try to find a file at `scripts/nolints-style.txt` --- and otherwise proceed with no style exceptions. This means mathlib can continue unchanged, and downstream projects can either add an explicit exceptions file, or proceed without any exceptions. After this PR, one should be able to run lint-style on a downstream project by `lake exe lint-style ProjectName`. Prompted by [this zulip discussion](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/lint-style.20for.20downstream.20libraries). --- - [x] depends on: #24570 - [x] depends on: #24953 (I did not test the last part.) [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-linter awaiting-author please-adopt	58/19	Mathlib/Tactic/Linter/TextBased.lean,scripts/lint-style.lean	2	21	['Vierkantor', 'adomani', 'github-actions', 'grunweg', 'joneugster', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	26-18001 26 days ago	unknown	unknown
37730	RemyDegenne author:RemyDegenne	feat: define total variation distance	Define the total variation distance between two finite measures, using the variation of the difference seen as signed measures. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	please-adopt WIP t-measure-probability	56/0	Mathlib.lean,Mathlib/InformationTheory/TotalVariation/Basic.lean	2	1	['github-actions']	nobody	15-23535 15 days ago	unknown	unknown
34501	eric-wieser author:eric-wieser	chore(Data/Fintype/Induction): add a workaround for a bug in `induction`	This works around leanprover/lean4#4246, as Zulip threads frequently run up against this. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-author t-meta please-adopt	15/1	Mathlib/Data/Fintype/Option.lean	1	3	['github-actions', 'joneugster']	joneugster assignee:joneugster	5-31756 5 days ago	82-1633 82 days ago	2-56184 2 days
35193	Brian-Nugent author:Brian-Nugent	feat(Topology/Closeds): implement category of closed sets in topological spaces	I copied over the nice API for working with `TopologicalSpace.Opens` as a category over for `TopologicalSpace.Closeds`. The only thing that did not immediately transfer was `Topology.IsInducing.functorObj` so I omitted it. Based on work of @kim-em --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology new-contributor please-adopt	352/6	Mathlib.lean,Mathlib/Topology/Category/TopCat/Closeds.lean,Mathlib/Topology/Category/TopCat/Opens.lean	3	23	['Brian-Nugent', 'dagurtomas', 'github-actions']	dagurtomas assignee:dagurtomas	4-75470 4 days ago	32-83836 32 days ago	17-61064 17 days
32989	kim-em author:kim-em	fix(Tactic/Simps): skip @[defeq] inference for non-exposed definitions	This PR makes `@[simps]` check whether the source definition's body is exposed before calling `inferDefEqAttr`. When the body is not exposed, we skip the `@[defeq]` inference to avoid validation errors. Without this fix, using `@[simps]` on a definition that is not `@[expose]`d produces an error like: ``` Theorem Foo_bar has a `rfl`-proof and was thus inferred to be `@[defeq]`, but validating that attribute failed: Not a definitional equality: the left-hand side ... is not definitionally equal to the right-hand side ... Note: This theorem is exported from the current module. This requires that all definitions that need to be unfolded to prove this theorem must be exposed. ``` The fix checks `(← getEnv).setExporting true \|>.find? cfg.srcDeclName \|>.any (·.hasValue)` to determine if the definition body is visible in the public scope, and only calls `inferDefEqAttr` if it is. 🤖 Prepared with Claude Code	t-meta awaiting-author LLM-generated please-adopt	50/2	Mathlib/CategoryTheory/Triangulated/TStructure/TruncLTGE.lean,Mathlib/Tactic/Simps/Basic.lean,MathlibTest/SimpsModule.lean	3	17	['JovanGerb', 'Vierkantor', 'github-actions', 'joneugster', 'kim-em', 'mathlib-merge-conflicts']	joneugster assignee:joneugster	4-59062 4 days ago	89-12694 89 days ago	37-2239 37 days
35341	grunweg author:grunweg	feat: lint against the tactic.skipAssignedInstances option in mathlib	This means we can remove the corresponding technical debt entry. Re-created version of #20872. --- [This comment](https://github.com/leanprover-community/mathlib4/pull/20872#issuecomment-2602743770) might still be relevant: does this linter need adaptations to recursively parse the outer `set_option`s? Wasn't there code written semi-recently which did this? [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	please-adopt t-linter merge-conflict	54/3	Mathlib/Tactic/Linter/Style.lean,MathlibTest/LintStyle.lean	2	3	['github-actions', 'mathlib-merge-conflicts']	nobody	0-60547 16 hours ago	unknown	unknown
35545	joelriou author:joelriou	feat(Algebra/Category/ModuleCat): the internal hom for presheaves of modules	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra WIP please-adopt label:t-algebra$	141/0	Mathlib.lean,Mathlib/Algebra/Category/ModuleCat/Presheaf/InternalHom.lean,Mathlib/Algebra/Category/ModuleCat/Presheaf/Pushforward.lean	3	1	['github-actions']	nobody	0-26640 7 hours ago	unknown	unknown
38334	8e7 author:8e7	feat(Combinatorics/SimpleGraph/TreeDecomp): define tree decompositions	Add definition for tree decompositions on simple graphs. Define the tree width of a simple graph and prove basic statements and conversions. ```lean structure TreeDecomp (G : SimpleGraph V) where /-- The type of bags in the tree. -/ W : Type u /-- The set of vertices in each bag. -/ 𝓧 : W → Finset V /-- The graph adjacency relation of bags. -/ T : SimpleGraph W /-- T must be a tree. -/ isTree : IsTree T /-- All vertices in G must appear in some bag. -/ vertexCover : ∀ v : V, ∃ w : W, v ∈ 𝓧 w /-- For any edge (u, v) in G, there is a bag containing both u and v. -/ edgeCover ⦃u v : V⦄ : G.Adj u v → ∃ w : W, u ∈ 𝓧 w ∧ v ∈ 𝓧 w /-- For any vertex v in G, the set of bags that contain v is preconnected. -/ connectedBags : ∀ v : V, (T.induce ({w \| v ∈ 𝓧 w})).Preconnected ``` AI Usage: Some proofs are written with the help of Claude Code, and everything has been manually reviewed. --- - [ ] depends on: #38027 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor help-wanted blocked-by-other-PR t-combinatorics LLM-generated	396/0	Mathlib.lean,Mathlib/Combinatorics/SimpleGraph/Star.lean,Mathlib/Combinatorics/SimpleGraph/TreeDecomp.lean	3	4	['8e7', 'github-actions', 'mathlib-dependent-issues']	nobody	0-21387 5 hours ago	unknown	unknown

PRs with just a merge conflict

Number	Author	Title	Description	Labels	+/-	Modified files (first 100)	📝	💬	All users who commented or reviewed	Assignee(s)	Updated	Last status change	total time in review
24823	eric-wieser author:eric-wieser	refactor: add `hom` lemmas for the `MonoidalCategory` structure on `ModuleCat`	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-algebra label:t-algebra$	148/164	Mathlib/Algebra/Category/FGModuleCat/Basic.lean,Mathlib/Algebra/Category/ModuleCat/Adjunctions.lean,Mathlib/Algebra/Category/ModuleCat/Monoidal/Basic.lean,Mathlib/Algebra/Category/ModuleCat/Monoidal/Closed.lean,Mathlib/Algebra/Category/ModuleCat/Monoidal/Symmetric.lean,Mathlib/Algebra/Category/ModuleCat/Presheaf/Free.lean,Mathlib/Algebra/Category/ModuleCat/Presheaf/Generator.lean,Mathlib/Algebra/Category/ModuleCat/Presheaf/Monoidal.lean,Mathlib/CategoryTheory/Monoidal/Internal/Module.lean,Mathlib/RepresentationTheory/Coinvariants.lean,Mathlib/RepresentationTheory/Rep.lean	11	21	['101damnations', 'YaelDillies', 'eric-wieser', 'github-actions', 'joelriou', 'kbuzzard', 'leanprover-community-bot-assistant']	101damnations assignee:101damnations	291-39927 9 months ago	291-39927 291 days ago	25-46309 25 days
25988	Multramate author:Multramate	refactor(AlgebraicGeometry/EllipticCurve/*): replace Fin 3 with products	This PR continues the work from #24593. Original PR: https://github.com/leanprover-community/mathlib4/pull/24593	merge-conflict t-algebraic-geometry	1000/1022	Mathlib/AlgebraicGeometry/EllipticCurve/Jacobian/Basic.lean,Mathlib/AlgebraicGeometry/EllipticCurve/Jacobian/Formula.lean,Mathlib/AlgebraicGeometry/EllipticCurve/Jacobian/Point.lean,Mathlib/AlgebraicGeometry/EllipticCurve/Projective/Basic.lean,Mathlib/AlgebraicGeometry/EllipticCurve/Projective/Formula.lean,Mathlib/AlgebraicGeometry/EllipticCurve/Projective/Point.lean	6	3	['Multramate', 'github-actions', 'leanprover-community-bot-assistant']	nobody	291-39369 9 months ago	unknown	unknown
26067	mapehe author:mapehe	feat(Topology/StoneCech): exists_continuous_surjection_from_StoneCech_to_dense_range	This lemma formalises the following version of the maximality property of the Stone–Čech compactification: If `f : α → β` is a continuous map from a topological space `α` to a Hausdorff space `β` with dense range, then there exists a continuous surjection from `StoneCech α` to `β` extending `f`. In particular, `StoneCech α` is the “largest” compact Hausdorff space into which `α` densely embeds, in the sense that any other such space is a continuous image of it. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-topology	18/0	Mathlib/Topology/StoneCech.lean	1	2	['github-actions', 'leanprover-community-bot-assistant']	nobody	288-20747 9 months ago	288-20747 288 days ago	20-8050 20 days
26200	adomani author:adomani	fix: add label when landrun fails	Adds the `permission-denied` label on PRs that get blocked by landrun. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict CI	68/8	.github/build.in.yml,.github/workflows/bors.yml,.github/workflows/build.yml,.github/workflows/build_fork.yml	4	2	['github-actions', 'mathlib4-merge-conflict-bot']	nobody	259-55362 8 months ago	259-55362 259 days ago	46-51722 46 days
27451	kckennylau author:kckennylau	feat(RingTheory/Valuation): define ball, closed ball, and sphere	From the 2025 Local Class Field Theory Workshop. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-ring-theory	27/0	Mathlib/RingTheory/Valuation/Basic.lean	1	13	['JovanGerb', 'github-actions', 'kckennylau', 'mathlib4-merge-conflict-bot', 'pechersky', 'wwylele']	nobody	254-1465 8 months ago	254-1466 254 days ago	17-51735 17 days
27987	kckennylau author:kckennylau	feat(RingTheory/Valuation): define ball, closed ball, and sphere	--- The pullback PR of #26827 and #27451. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-ring-theory large-import	73/0	Mathlib/RingTheory/Valuation/Basic.lean	1	4	['JovanGerb', 'github-actions', 'kckennylau', 'mathlib4-merge-conflict-bot']	nobody	254-1094 8 months ago	254-1095 254 days ago	6-5823 6 days
27003	eric-wieser author:eric-wieser	chore: use `Simp.ResultQ` more often	Also uses `~q` in place of manual `isDefEq` matching. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-meta	18/22	Mathlib/Tactic/NormNum/Core.lean,Mathlib/Tactic/NormNum/Result.lean,Mathlib/Tactic/ReduceModChar.lean	3	7	['JovanGerb', 'eric-wieser', 'github-actions', 'mathlib4-merge-conflict-bot']	JovanGerb assignee:JovanGerb	252-15718 8 months ago	252-15719 252 days ago	32-67299 32 days
28622	alreadydone author:alreadydone	chore(Mathlib): replace `=>` by `↦`	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict	51792/51792	Mathlib/Algebra/AddTorsor/Basic.lean,Mathlib/Algebra/AddTorsor/Defs.lean,Mathlib/Algebra/Algebra/Basic.lean,Mathlib/Algebra/Algebra/Bilinear.lean,Mathlib/Algebra/Algebra/Defs.lean,Mathlib/Algebra/Algebra/Equiv.lean,Mathlib/Algebra/Algebra/Hom.lean,Mathlib/Algebra/Algebra/Hom/Rat.lean,Mathlib/Algebra/Algebra/NonUnitalHom.lean,Mathlib/Algebra/Algebra/NonUnitalSubalgebra.lean,Mathlib/Algebra/Algebra/Operations.lean,Mathlib/Algebra/Algebra/Opposite.lean,Mathlib/Algebra/Algebra/Prod.lean,Mathlib/Algebra/Algebra/Rat.lean,Mathlib/Algebra/Algebra/Spectrum/Basic.lean,Mathlib/Algebra/Algebra/Spectrum/Pi.lean,Mathlib/Algebra/Algebra/Spectrum/Quasispectrum.lean,Mathlib/Algebra/Algebra/Subalgebra/Basic.lean,Mathlib/Algebra/Algebra/Subalgebra/Centralizer.lean,Mathlib/Algebra/Algebra/Subalgebra/Directed.lean,Mathlib/Algebra/Algebra/Subalgebra/IsSimpleOrder.lean,Mathlib/Algebra/Algebra/Subalgebra/Lattice.lean,Mathlib/Algebra/Algebra/Subalgebra/Matrix.lean,Mathlib/Algebra/Algebra/Subalgebra/Operations.lean,Mathlib/Algebra/Algebra/Subalgebra/Pointwise.lean,Mathlib/Algebra/Algebra/Subalgebra/Prod.lean,Mathlib/Algebra/Algebra/Subalgebra/Unitization.lean,Mathlib/Algebra/Algebra/Tower.lean,Mathlib/Algebra/Algebra/TransferInstance.lean,Mathlib/Algebra/Algebra/Unitization.lean,Mathlib/Algebra/Algebra/ZMod.lean,Mathlib/Algebra/AlgebraicCard.lean,Mathlib/Algebra/BigOperators/Associated.lean,Mathlib/Algebra/BigOperators/Expect.lean,Mathlib/Algebra/BigOperators/Fin.lean,Mathlib/Algebra/BigOperators/Finprod.lean,Mathlib/Algebra/BigOperators/Finsupp/Basic.lean,Mathlib/Algebra/BigOperators/Finsupp/Fin.lean,Mathlib/Algebra/BigOperators/Group/Finset/Basic.lean,Mathlib/Algebra/BigOperators/Group/Finset/Defs.lean,Mathlib/Algebra/BigOperators/Group/Finset/Piecewise.lean,Mathlib/Algebra/BigOperators/Group/Finset/Sigma.lean,Mathlib/Algebra/BigOperators/Group/List/Basic.lean,Mathlib/Algebra/BigOperators/Group/List/Defs.lean,Mathlib/Algebra/BigOperators/Group/List/Lemmas.lean,Mathlib/Algebra/BigOperators/Group/Multiset/Basic.lean,Mathlib/Algebra/BigOperators/Group/Multiset/Defs.lean,Mathlib/Algebra/BigOperators/GroupWithZero/Finset.lean,Mathlib/Algebra/BigOperators/Intervals.lean,Mathlib/Algebra/BigOperators/Option.lean,Mathlib/Algebra/BigOperators/Pi.lean,Mathlib/Algebra/BigOperators/Ring/Finset.lean,Mathlib/Algebra/BigOperators/Ring/Multiset.lean,Mathlib/Algebra/Category/AlgCat/Basic.lean,Mathlib/Algebra/Category/AlgCat/Limits.lean,Mathlib/Algebra/Category/AlgCat/Monoidal.lean,Mathlib/Algebra/Category/BialgCat/Basic.lean,Mathlib/Algebra/Category/BoolRing.lean,Mathlib/Algebra/Category/CoalgCat/Basic.lean,Mathlib/Algebra/Category/CoalgCat/ComonEquivalence.lean,Mathlib/Algebra/Category/FGModuleCat/Limits.lean,Mathlib/Algebra/Category/Grp/AB.lean,Mathlib/Algebra/Category/Grp/Adjunctions.lean,Mathlib/Algebra/Category/Grp/Basic.lean,Mathlib/Algebra/Category/Grp/Biproducts.lean,Mathlib/Algebra/Category/Grp/CartesianMonoidal.lean,Mathlib/Algebra/Category/Grp/Colimits.lean,Mathlib/Algebra/Category/Grp/EpiMono.lean,Mathlib/Algebra/Category/Grp/FilteredColimits.lean,Mathlib/Algebra/Category/Grp/Images.lean,Mathlib/Algebra/Category/Grp/Kernels.lean,Mathlib/Algebra/Category/Grp/LargeColimits.lean,Mathlib/Algebra/Category/Grp/LeftExactFunctor.lean,Mathlib/Algebra/Category/Grp/Limits.lean,Mathlib/Algebra/Category/Grp/Preadditive.lean,Mathlib/Algebra/Category/Grp/ZModuleEquivalence.lean,Mathlib/Algebra/Category/Grp/Zero.lean,Mathlib/Algebra/Category/GrpWithZero.lean,Mathlib/Algebra/Category/HopfAlgCat/Basic.lean,Mathlib/Algebra/Category/ModuleCat/Adjunctions.lean,Mathlib/Algebra/Category/ModuleCat/Basic.lean,Mathlib/Algebra/Category/ModuleCat/Biproducts.lean,Mathlib/Algebra/Category/ModuleCat/ChangeOfRings.lean,Mathlib/Algebra/Category/ModuleCat/Colimits.lean,Mathlib/Algebra/Category/ModuleCat/EpiMono.lean,Mathlib/Algebra/Category/ModuleCat/FilteredColimits.lean,Mathlib/Algebra/Category/ModuleCat/Images.lean,Mathlib/Algebra/Category/ModuleCat/Injective.lean,Mathlib/Algebra/Category/ModuleCat/Kernels.lean,Mathlib/Algebra/Category/ModuleCat/Limits.lean,Mathlib/Algebra/Category/ModuleCat/Monoidal/Basic.lean,Mathlib/Algebra/Category/ModuleCat/Monoidal/Closed.lean,Mathlib/Algebra/Category/ModuleCat/Monoidal/Symmetric.lean,Mathlib/Algebra/Category/ModuleCat/Presheaf.lean,Mathlib/Algebra/Category/ModuleCat/Presheaf/Abelian.lean,Mathlib/Algebra/Category/ModuleCat/Presheaf/Colimits.lean,Mathlib/Algebra/Category/ModuleCat/Presheaf/Limits.lean,Mathlib/Algebra/Category/ModuleCat/Presheaf/Pushforward.lean,Mathlib/Algebra/Category/ModuleCat/Presheaf/Sheafify.lean,Mathlib/Algebra/Category/ModuleCat/Products.lean	3838	4	['github-actions', 'mathlib4-merge-conflict-bot']	nobody	245-60394 8 months ago	245-60395 245 days ago	0-55389 15 hours
28626	alreadydone author:alreadydone	chore(Archive, Counterexamples): replace => by ↦	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict	288/288	Archive/Arithcc.lean,Archive/Examples/IfNormalization/Result.lean,Archive/Examples/IfNormalization/WithoutAesop.lean,Archive/Examples/PropEncodable.lean,Archive/Imo/Imo1959Q1.lean,Archive/Imo/Imo1960Q1.lean,Archive/Imo/Imo1962Q4.lean,Archive/Imo/Imo1972Q5.lean,Archive/Imo/Imo1977Q6.lean,Archive/Imo/Imo1981Q3.lean,Archive/Imo/Imo1987Q1.lean,Archive/Imo/Imo1988Q6.lean,Archive/Imo/Imo1994Q1.lean,Archive/Imo/Imo1998Q2.lean,Archive/Imo/Imo2001Q2.lean,Archive/Imo/Imo2006Q3.lean,Archive/Imo/Imo2006Q5.lean,Archive/Imo/Imo2008Q2.lean,Archive/Imo/Imo2008Q4.lean,Archive/Imo/Imo2011Q3.lean,Archive/Imo/Imo2013Q1.lean,Archive/Imo/Imo2019Q1.lean,Archive/Imo/Imo2024Q5.lean,Archive/MiuLanguage/Basic.lean,Archive/MiuLanguage/DecisionSuf.lean,Archive/OxfordInvariants/Summer2021/Week3P1.lean,Archive/Sensitivity.lean,Archive/Wiedijk100Theorems/AbelRuffini.lean,Archive/Wiedijk100Theorems/AreaOfACircle.lean,Archive/Wiedijk100Theorems/AscendingDescendingSequences.lean,Archive/Wiedijk100Theorems/BallotProblem.lean,Archive/Wiedijk100Theorems/BirthdayProblem.lean,Archive/Wiedijk100Theorems/BuffonsNeedle.lean,Archive/Wiedijk100Theorems/CubingACube.lean,Archive/Wiedijk100Theorems/FriendshipGraphs.lean,Archive/Wiedijk100Theorems/Konigsberg.lean,Archive/Wiedijk100Theorems/Partition.lean,Archive/Wiedijk100Theorems/SumOfPrimeReciprocalsDiverges.lean,Archive/ZagierTwoSquares.lean,Counterexamples/AharoniKorman.lean,Counterexamples/CanonicallyOrderedCommSemiringTwoMul.lean,Counterexamples/CharPZeroNeCharZero.lean,Counterexamples/CliffordAlgebraNotInjective.lean,Counterexamples/DirectSumIsInternal.lean,Counterexamples/GameMultiplication.lean,Counterexamples/Girard.lean,Counterexamples/HomogeneousPrimeNotPrime.lean,Counterexamples/MapFloor.lean,Counterexamples/MonicNonRegular.lean,Counterexamples/Phillips.lean,Counterexamples/Pseudoelement.lean,Counterexamples/QuadraticForm.lean,Counterexamples/SorgenfreyLine.lean,Counterexamples/ZeroDivisorsInAddMonoidAlgebras.lean	54	2	['github-actions', 'mathlib4-merge-conflict-bot']	nobody	244-3120 8 months ago	244-3121 244 days ago	2-46227 2 days
28150	Equilibris author:Equilibris	chore: clean up proofs typevec proofs	While adding variable universe corecs I found a lot of theorems in typevec that could do with a bit of a clean-up --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-data new-contributor	24/26	Mathlib/Data/TypeVec.lean	1	7	['Equilibris', 'alexkeizer', 'github-actions', 'mathlib4-merge-conflict-bot']	nobody	242-56836 7 months ago	242-56837 242 days ago	13-47613 13 days
27403	MoritzBeroRoos author:MoritzBeroRoos	fix: replace probably erroneous usage of ⬝ (with old \cdot) by · (with \centerdot)	Discussion at [zulip](https://leanprover.zulipchat.com/#narrow/channel/270676-lean4/topic/.5Ccdot.20!.3D.20.5Ccenterdot). Currently the abbreviations \cdot and \centerdot resolve to different, with the naked eye nearly undistinguishable symbols (despite the c in cdot surely standing for center..). This pr replaces instances of ⬝ where · was probably meant. All of the replacement is in comments, except for the file bench_summary.lean which is used for priting the github benchmark results. Since this file is about scientific notation of numbers, sure · was meant to be used, not a rectangle. [Related](https://github.com/leanprover-community/mathlib4/pull/27399) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict new-contributor	195/195	Mathlib/Algebra/ContinuedFractions/Computation/Approximations.lean,Mathlib/Algebra/DirectSum/Idempotents.lean,Mathlib/Algebra/Lie/Derivation/Basic.lean,Mathlib/Algebra/Module/Equiv/Basic.lean,Mathlib/AlgebraicGeometry/EllipticCurve/DivisionPolynomial/Basic.lean,Mathlib/Analysis/Analytic/Constructions.lean,Mathlib/Analysis/CStarAlgebra/CStarMatrix.lean,Mathlib/Analysis/Calculus/ContDiff/Basic.lean,Mathlib/Analysis/Calculus/ContDiff/Bounds.lean,Mathlib/Analysis/Calculus/FDeriv/Symmetric.lean,Mathlib/Analysis/Fourier/FourierTransformDeriv.lean,Mathlib/Analysis/InnerProductSpace/Dual.lean,Mathlib/Analysis/InnerProductSpace/PiL2.lean,Mathlib/Analysis/Normed/Unbundled/InvariantExtension.lean,Mathlib/Analysis/SpecialFunctions/Complex/CircleAddChar.lean,Mathlib/Combinatorics/Configuration.lean,Mathlib/Combinatorics/SimpleGraph/AdjMatrix.lean,Mathlib/Combinatorics/SimpleGraph/LapMatrix.lean,Mathlib/Data/Matrix/Block.lean,Mathlib/Data/Matrix/ConjTranspose.lean,Mathlib/Data/Matrix/Hadamard.lean,Mathlib/Data/Matrix/Mul.lean,Mathlib/Data/Matrix/Notation.lean,Mathlib/Data/Matrix/Reflection.lean,Mathlib/Data/Matrix/RowCol.lean,Mathlib/Data/Matrix/Vec.lean,Mathlib/FieldTheory/PurelyInseparable/PerfectClosure.lean,Mathlib/Geometry/Manifold/GroupLieAlgebra.lean,Mathlib/GroupTheory/Coxeter/Matrix.lean,Mathlib/LinearAlgebra/CrossProduct.lean,Mathlib/LinearAlgebra/Matrix/BilinearForm.lean,Mathlib/LinearAlgebra/Matrix/DotProduct.lean,Mathlib/LinearAlgebra/Matrix/Nondegenerate.lean,Mathlib/LinearAlgebra/Matrix/Orthogonal.lean,Mathlib/LinearAlgebra/Matrix/PosDef.lean,Mathlib/LinearAlgebra/Matrix/SchurComplement.lean,Mathlib/LinearAlgebra/Matrix/SesquilinearForm.lean,Mathlib/LinearAlgebra/Matrix/Trace.lean,Mathlib/LinearAlgebra/Multilinear/Basic.lean,Mathlib/LinearAlgebra/PerfectPairing/Matrix.lean,Mathlib/LinearAlgebra/Projectivization/Constructions.lean,Mathlib/NumberTheory/NumberField/ProductFormula.lean,Mathlib/NumberTheory/SiegelsLemma.lean,Mathlib/RingTheory/DividedPowers/SubDPIdeal.lean,Mathlib/SetTheory/Ordinal/Veblen.lean,Mathlib/Topology/Algebra/Module/Equiv.lean,Mathlib/Topology/Homeomorph/Lemmas.lean,Mathlib/Topology/Instances/Matrix.lean,scripts/bench_summary.lean	49	5	['eric-wieser', 'github-actions', 'grunweg', 'leanprover-community-bot-assistant']	nobody	242-36156 7 months ago	265-12078 265 days ago	7-51497 7 days
28042	kckennylau author:kckennylau	feat(Topology/ValuativeRel): a topological basis indexed by pairs of elements	--- The pullback PR of #27314 and #27163. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-ring-theory	140/23	Mathlib/RingTheory/Valuation/ValuativeRel.lean,Mathlib/Topology/Algebra/Valued/ValuativeRel.lean	2	3	['github-actions', 'grunweg', 'mathlib4-merge-conflict-bot']	nobody	242-36110 7 months ago	252-1154 252 days ago	7-2766 7 days
27399	MoritzBeroRoos author:MoritzBeroRoos	chore: replace every usage of ⬝ᵥ (with old \cdot) by ·ᵥ (with \centerdot)	Discussion at [zulip](https://leanprover.zulipchat.com/#narrow/channel/270676-lean4/topic/.5Ccdot.20!.3D.20.5Ccenterdot). Currently the abbreviations `\cdot` and `\centerdot` resolve to different, with the naked eye nearly undistinguishable symbols (despite the c in cdot surely standing for `center`..): - `\cdot` gives ⬝ [U+2B1D](https://www.compart.com/en/unicode/U+2B1D) "Black Very Small Square" - `\centerdot` gives · [U+00B7](https://www.compart.com/en/unicode/U+00B7) "Middle Dot" Mathlib mostly uses the `\centerdot` variant, except for the dotProduct notation and some probably unsuspecting people wanting \centerdot but getting \cdot in their comments and 6 uses of a notation using the raw `\cdot` without any subscript at `Mathlib\Topology\Homotopy\Product.lean`. This PR replaces the dot product `⬝ᵥ` with its `\centerdot` counterpart `·ᵥ`. The related PR [here](https://github.com/leanprover/vscode-lean4/pull/639) can then overwrite the `\cdot` abbreviation, to produce the same symbol as the `centerdot` abbreviation does. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict new-contributor	133/133	Mathlib/Analysis/CStarAlgebra/CStarMatrix.lean,Mathlib/Analysis/InnerProductSpace/PiL2.lean,Mathlib/Combinatorics/Configuration.lean,Mathlib/Combinatorics/SimpleGraph/AdjMatrix.lean,Mathlib/Combinatorics/SimpleGraph/LapMatrix.lean,Mathlib/Data/Matrix/Block.lean,Mathlib/Data/Matrix/ConjTranspose.lean,Mathlib/Data/Matrix/Hadamard.lean,Mathlib/Data/Matrix/Mul.lean,Mathlib/Data/Matrix/Notation.lean,Mathlib/Data/Matrix/Reflection.lean,Mathlib/Data/Matrix/RowCol.lean,Mathlib/Data/Matrix/Vec.lean,Mathlib/LinearAlgebra/CrossProduct.lean,Mathlib/LinearAlgebra/Matrix/BilinearForm.lean,Mathlib/LinearAlgebra/Matrix/DotProduct.lean,Mathlib/LinearAlgebra/Matrix/Nondegenerate.lean,Mathlib/LinearAlgebra/Matrix/Orthogonal.lean,Mathlib/LinearAlgebra/Matrix/PosDef.lean,Mathlib/LinearAlgebra/Matrix/SchurComplement.lean,Mathlib/LinearAlgebra/Matrix/SesquilinearForm.lean,Mathlib/LinearAlgebra/Matrix/Trace.lean,Mathlib/LinearAlgebra/PerfectPairing/Matrix.lean,Mathlib/LinearAlgebra/Projectivization/Constructions.lean,Mathlib/Topology/Instances/Matrix.lean	25	6	['MoritzBeroRoos', 'eric-wieser', 'github-actions', 'leanprover-community-bot-assistant']	nobody	241-84388 7 months ago	265-12079 265 days ago	7-53541 7 days
28148	kckennylau author:kckennylau	feat(Matrix): Simproc and Rw-proc for Matrix Transpose	Co-authored by Aaron Liu. ```lean example : !![1, 2, 3; 4, 5, 6]ᵀ = !![1, 4; 2, 5; 3, 6] := by rw [transpose_of% 2 3] example : !![1, 2, 3; 4, 5, 6]ᵀ = !![1, 4; 2, 5; 3, 6] := by rw [transpose_of] example : !![1, 2, 3; 4, 5, 6]ᵀ = !![1, 4; 2, 5; 3, 6] := by simp only [matrix_transpose] ``` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-meta	267/8	Mathlib.lean,Mathlib/Data/Matrix/Notation.lean,Mathlib/LinearAlgebra/UnitaryGroup.lean,Mathlib/Tactic.lean,Mathlib/Tactic/Simproc/Matrix.lean,MathlibTest/Simproc/Matrix.lean,MathlibTest/matrix.lean,scripts/noshake.json	8	32	['eric-wieser', 'github-actions', 'kckennylau', 'mathlib4-merge-conflict-bot', 'plp127']	eric-wieser assignee:eric-wieser	237-41322 7 months ago	237-41323 237 days ago	12-66568 12 days
26908	robin-carlier author:robin-carlier	feat(CategoryTheory/Monoidal/DayConvolution): alternative ext principle for unitors	Currently, our infrastructure for left/right unitors for Day convolution of functors `C ⥤ V` do not have satisfactory extensionality principle: the current way to characterize morphisms out of `U ⊛ F` is the default extensionality principle for Day convolution, which characterizes first such functors via functors out of `U ⊠ F`. Left unitors are then obtained using the fact `U ⊠ F` is a left Kan extension of a functor from `PUnit × C` (which is equivalent to `C`) but we did not record on its own this principle. Using the transitivity of left Kan extensions proved in #26899, we directly exhibit `U ⊛ F` as a left Kan extension of `F ⋙ tensorLeft (𝟙_ V)` along `tensorLeft (𝟙_ C)`. The unit of this Kan extension is composed exactly of the morphisms that appear in the [characterization of left unitors](https://leanprover-community.github.io/mathlib4_docs/Mathlib/CategoryTheory/Monoidal/DayConvolution.html#CategoryTheory.MonoidalCategory.DayConvolutionUnit.leftUnitor_hom_unit_app). We also slightly generalize the instances that express that external products with unitors are left Kan extensions, so that they can be used when taking external products with more complicated functors than currently. This is again useful when chaining extensionality lemmas for morphisms out of terms of the form `(F ⊛ U) ⊛ G`. We prove a similar thing for right unitors With this, it should be possible to have a much more satisfactory way of working with Day convolutions: this allows to "elimiinate" units without ending up with terms in an external product. --- - [ ] depends on: #26899 - [ ] depends on: #26906 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-category-theory	307/18	Mathlib/CategoryTheory/Functor/KanExtension/Basic.lean,Mathlib/CategoryTheory/Monoidal/DayConvolution.lean	2	4	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	226-1268 7 months ago	226-1269 226 days ago	0-1045 17 minutes
27150	robin-carlier author:robin-carlier	feat(CategoryTheory/Monoidal/DayConvolution): constructors for braided and symmetric structure on day convolutions monoidal categories	Following the pattern in #27119, we give API to construct `BraidedCategory` and `SymmetricCategory` structures on a monoidal category equipped with a `LawfulDayConvolutionMonoidalCategoryStruct`. To achieve this, we introduce an other type class `LawfulDayConvolutionBraidedCategoryStruct` that bundles an associator isomorphism that behaves like the one constructed for functors in #27067. We provide a noncomputable constructor for this typeclass that takes as input fullness of the "realization" functor to a category of functors, and we show that the typeclasses are sufficient to define the desired structures. --- - [x] depends on: #27067 - [x] depends on: #26820 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-category-theory	826/9	Mathlib/CategoryTheory/Monoidal/DayConvolution.lean,Mathlib/CategoryTheory/Monoidal/DayConvolution/Braided.lean	2	5	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	225-82707 7 months ago	281-26409 281 days ago	0-51 51 seconds
27119	robin-carlier author:robin-carlier	feat(CategoryTheory/Monoidal/DayConvolution): constructors for closed monoidal day convolution monoidal structures	Following the pattern introduced in #26798 and #26820 and using results of #26879, we introduce a typeclass `LawfulDayConvolutionClosedMonoidalCategoryStruct` that encodes the data needed on a `LawfulDayConvolutionMonoidalCategoryStruct` to define well-behaved internal homs. We give a constructor assuming existence of relevant ends, and prove that this data defines a `MonoidalClosed` instance on the monoidal category structures one can deduce from `LawfulDayConvolutionMonoidalCategoryStruct`. --- - [x] depends on: #27079 - [x] depends on: #27091 - [x] depends on: #26879 - [x] depends on: #26820 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-category-theory	900/9	Mathlib/CategoryTheory/Monoidal/DayConvolution.lean,Mathlib/CategoryTheory/Monoidal/DayConvolution/Closed.lean	2	6	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	225-10158 7 months ago	unknown	unknown
28623	gilesgshaw author:gilesgshaw	feat(Logic/Basic): minor additions and simplification of proofs	Add new theorems and simplify proofs. Specifically, we add the family of related theorems `apply_dite_iff_exists`, `apply_dite_iff_forall`, `apply_ite_iff_and` and `apply_ite_iff_or`. For each other 'family' of theorems in the file that is analogous to the above, we do the following - Simplify proofs where possible, e.g. by appealing to the new theorems - Complete the family, if any of the corresponding four are missing - Rename to ensure consistency with the above pattern ---	merge-conflict t-logic new-contributor	83/55	Archive/Examples/IfNormalization/Result.lean,Archive/Examples/IfNormalization/WithoutAesop.lean,Mathlib/Algebra/ContinuedFractions/Computation/Translations.lean,Mathlib/Algebra/MvPolynomial/Variables.lean,Mathlib/Algebra/Notation/Indicator.lean,Mathlib/LinearAlgebra/Matrix/Rank.lean,Mathlib/Logic/Basic.lean,Mathlib/MeasureTheory/Measure/WithDensity.lean,Mathlib/SetTheory/Ordinal/Notation.lean	9	12	['eric-wieser', 'gilesgshaw', 'github-actions', 'mathlib4-merge-conflict-bot', 'plp127']	awainverse assignee:awainverse	225-4019 7 months ago	225-4020 225 days ago	10-53273 10 days
27933	grunweg author:grunweg	chore(OrdNode): format code example in code blocks	Wrap them in code blocks (and unindent them; that indentation is not needed any more). This also avoids warnings from the linter in #27898. ------- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-data	459/212	Mathlib/Data/Ordmap/Ordnode.lean	1	4	['eric-wieser', 'github-actions', 'grunweg', 'mathlib4-merge-conflict-bot']	nobody	221-41052 7 months ago	221-41053 221 days ago	39-68381 39 days
26154	ADedecker author:ADedecker	refactor: add refactored APIs for algebraic filter bases	This PR continues the work from #18437. Original PR: https://github.com/leanprover-community/mathlib4/pull/18437	merge-conflict t-topology	651/0	Mathlib.lean,Mathlib/Topology/Algebra/FilterBasis.lean,Mathlib/Topology/Algebra/FilterBasisNew.lean,Mathlib/Topology/Algebra/Nonarchimedean/Bases.lean,Mathlib/Topology/Algebra/Nonarchimedean/BasesNew.lean	5	3	['ADedecker', 'github-actions', 'mathlib4-merge-conflict-bot']	PatrickMassot assignee:PatrickMassot	219-16263 7 months ago	219-16264 219 days ago	87-78694 87 days
29330	plp127 author:plp127	chore: define `Fin.cycleIcc` with conditions	Redefine `Fin.cycleIcc` using conditionals instead of composing existing `Fin` operations together. Its worst-case runtime drops from O(n) to O(1). As a bonus, the definition no longer needs explaining. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-group-theory	61/68	Mathlib/GroupTheory/Perm/Fin.lean	1	10	['JovanGerb', 'eric-wieser', 'github-actions', 'mathlib4-merge-conflict-bot', 'plp127', 'tb65536']	nobody	210-27860 6 months ago	210-27861 210 days ago	19-72402 19 days
27214	robin-carlier author:robin-carlier	feat(CategoryTheory/Limits/Shapes/Pullback/Categorical): Categorical pullback squares	In this PR, we give the definition and first basic properties of categorical pullback squares. Using our previous work on `CategoricalPullback`, we define a typeclass `CatPullbackSquare T L R B` that asserts that a given `CatCommSq T L R B` is a "pullback square": this is the data of a chosen adjoint equivalence to the canonical functor from the top left corner of the square to the categorical pulback of its leg. Using this equivalence, be derive a universal property for functors from `X`with values in the top left corner of the square: they are equivalent to `CatCommSqOver R B X`, the category of categorical commutative squares over the cospan `R, B` with top left corner `X`. We prove some coherence result for this equivalence, most notably an isomorphism that, given `S : CatCommSqOver R B X`, bundles the two commutative triangles formed by the induced functor, and the coherence between the squares that these isomorphisms satisfy: this is conveniently bundled in the data of a single isomorphisms of `CatCommSqOver R B X`. Finally, we provide a `Prop`-class `IsCatPullbackSquare` that merely asserts the existence (via `Nonempty`) of the relevant data: we show that it is tautotogically equivalent to the propopsition that the canonical functor to the categorical pullback is an equivalence. --- - [ ] depends on: #26679 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-category-theory	786/1	Mathlib.lean,Mathlib/CategoryTheory/Limits/Shapes/Pullback/Categorical/Basic.lean,Mathlib/CategoryTheory/Limits/Shapes/Pullback/Categorical/Square.lean	3	3	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	204-79452 6 months ago	204-79453 204 days ago	0-4044 1 hour
26466	robin-carlier author:robin-carlier	feat(AlgebraicTopology/SimplexCategory/Augmented): the canonical monoid object in the augmented simplex category	Show that in the augmented simplex category, `⦋0⦌` is an internal monoid object. Future work will show that this is in fact the universal monoid object: for any monoidal category `C`, evaluation at `⦋0⦌` induces an equivalence of categories between `Mon_ C` and the category of monoidal functors from `AugmentedSimplexCategory` to `C`. The resulting augmented cosimplicial object one gets from this construction is sometimes called the "monoidal bar construction" attached to a monoid. This PR was split from #25743. --- - [ ] depends on: #25743 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-algebraic-topology t-category-theory	571/111	Mathlib.lean,Mathlib/AlgebraicTopology/SimplexCategory/Augmented.lean,Mathlib/AlgebraicTopology/SimplexCategory/Augmented/Basic.lean,Mathlib/AlgebraicTopology/SimplexCategory/Augmented/Mon_.lean,Mathlib/AlgebraicTopology/SimplexCategory/Augmented/Monoidal.lean,Mathlib/AlgebraicTopology/SimplexCategory/Basic.lean	6	4	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	204-12454 6 months ago	299-19738 299 days ago	0-1046 17 minutes
26578	robin-carlier author:robin-carlier	feat(CategoryTheory/Limits/Pullbacks/Categorical/CatCospanTransform): adjunctions of categorical cospans	We build upon the bicategory-like structure developed in #26447 and #26412 to define the notion of adjunctions of categorical cospans. This is a structure encoding the data of two `CatCospanTransform`s, along with the usual unit and counit morphisms as part of the data, satisfying the usual left and right triangle identities. We provide basic API for these, such as extracting adjunctions between individual components. We also provide a proof that the notion satisfies a "coherence": with our chosen constructor, the forward direction of the structure `CatCommSq` on the left adjoints correspond to the inverse of the square for the right adjoints through `mateEquiv`. These adjunctions will be used as a substrate for defining equivalences of categorical cospans in a future PR: such an equivalence will be a structure extending a `CatCospanAdjunction` with isomorphisms data on the unit and co-unit (we will however provide alternative constructors in sync with the constructor for equivalences of categories). --- - [x] depends on: #26447 - [x] depends on: #26547 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-category-theory large-import	205/0	Mathlib/CategoryTheory/Limits/Shapes/Pullback/Categorical/CatCospanTransform.lean	1	5	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	203-15679 6 months ago	unknown	unknown
27990	kckennylau author:kckennylau	feat(Counterexamples): a nontrivial valuation with discrete topology	This file constructs a valuation on `K[X]` satisfying `IsValuativeTopology K[X] ∧ Nonempty (valuation K[X]).RankOne ∧ IsNontrivial K[X] ∧ DiscreteTopology K[X]`, and proves that `IsValuativeTopology F ∧ IsNontrivial F ∧ DiscreteTopology F` is not possible if `F` is a field. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-ring-theory	172/0	Counterexamples.lean,Counterexamples/DiscreteTopologyWithNontrivialValuation.lean	2	14	['github-actions', 'grunweg', 'kckennylau', 'mathlib4-merge-conflict-bot', 'pechersky']	nobody	191-85925 6 months ago	191-85926 191 days ago	67-78029 67 days
28132	dupuisf author:dupuisf	feat: preliminary `grind` tags for `IsUnit`	This PR adds preliminary `grind` tags for the `IsUnit` predicate. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-algebra label:t-algebra$	61/17	Mathlib/Algebra/Group/Action/Units.lean,Mathlib/Algebra/Group/Units/Defs.lean,Mathlib/Algebra/GroupWithZero/Units/Basic.lean,Mathlib/Algebra/Ring/Units.lean,Mathlib/Analysis/CStarAlgebra/ContinuousFunctionalCalculus/Order.lean,Mathlib/Analysis/SpecialFunctions/ContinuousFunctionalCalculus/Rpow/Basic.lean	6	3	['github-actions', 'mathlib4-merge-conflict-bot']	kim-em assignee:kim-em	168-62523 5 months ago	168-62524 168 days ago	80-71574 80 days
26827	pechersky author:pechersky	feat(Analysis/Normed/ValuativeRel): helper instance for NormedField	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) - [x] depends on: #26713 - [x] depends on: #26826	merge-conflict t-algebra t-number-theory t-analysis label:t-algebra$	211/27	Mathlib.lean,Mathlib/Analysis/Normed/ValuativeRel.lean,Mathlib/Topology/Algebra/Valued/ValuativeRel.lean	3	34	['ADedecker', 'adamtopaz', 'erdOne', 'github-actions', 'kbuzzard', 'kckennylau', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'pechersky']	kbuzzard assignee:kbuzzard	161-4727 5 months ago	161-4727 161 days ago	121-75550 121 days
24850	pechersky author:pechersky	feat(Topology/UniformSpace/Ultra): uniform spaces induced by pseudometrics are ultra if system is ultra	Any uniform space has a natural system of pseudometrics definable on it, comprised of those pseudometrics constructed from a descending chain of equivalence relation entourages. In a nonarchimedean uniformity, this pseudometric system induces the uniformity. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) - [x] depends on: #23111	merge-conflict t-topology	509/1	Mathlib.lean,Mathlib/Topology/MetricSpace/BundledFun.lean,Mathlib/Topology/UniformSpace/Ultra/Pseudometrizable.lean	3	9	['ADedecker', 'fpvandoorn', 'github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'pechersky']	urkud assignee:urkud	154-27214 5 months ago	154-27215 154 days ago	162-10999 162 days
26914	quangvdao author:quangvdao	feat(Data/PFunctor/Univariate): more definitions for univariate `PFunctor`	This PR defines several basic definitions of `PFunctor`, including zero, one, constants, monomials, coproduct (sum), product, sigma, pi, tensor product, universe lifting, and equivalence. We also add: (1) simple lemmas connecting the basic definitions, (2) an automatically derived ext lemma for `PFunctor` via `@[ext]` attribute Some things I'm not clear on: - I define `HAdd` and `HMul` instances for coproduct and product of poly functors having different universe levels. Should I also define `Add` and `Mul` instances for poly functors having the same universe level? - Is it ok to define notation for tensor product, i.e. `@[inherit_doc] scoped infixr:80 " ⊗ " => tensor`? I'm worried it might clash with other notation. - Need a double-check on the priority of notation. Some future definitions to add: - Various equivalences arising from arithmetic identities, e.g., `P + 0 ≃ₚ P`. - Definitions of Lenses and Charts (each of them will be a file or even a folder) - Exponential objects (corresponding to both `prod` and `tensor`) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-data	144/5	Mathlib/Data/PFunctor/Univariate/Basic.lean	1	20	['alexkeizer', 'eric-wieser', 'github-actions', 'mathlib4-merge-conflict-bot', 'quangvdao']	eric-wieser assignee:eric-wieser	154-26692 5 months ago	154-26693 154 days ago	133-15886 133 days
28125	nonisomorphiclinearmap author:nonisomorphiclinearmap	feat(Combinatorics): basic definition of simplicial complexes	This PR introduces the basic definition of a finite (abstract) simplicial complex, located in Mathlib/Combinatorics/SimplicialComplex/Basic.lean. --- This is our first contribution to mathlib. This work was done as part of the Fields Institute Summer Undergraduate Program on formalization in topological combinatorics. Eventually, we aim to formalize Lovasz's proof of the Kneser Conjecture and this is a small stepping stone in that direction. Some other commits will shortly depend on this one. We would like to acknowledge the Fields Institute for Research in Mathematical Sciences for their sponsorship. We would also like to thank our supervisors, Professor Chris Kapulkin and Mr. Daniel Carranza, for their guidance and support throughout this project. We would also like to thank our group members Tom Lindquist and Quang Minh Nguyen for our fruitful discussions.	merge-conflict t-combinatorics new-contributor	374/0	Mathlib.lean,Mathlib/Combinatorics/SimplicialComplex/Basic.lean,Mathlib/Combinatorics/SimplicialComplex/Category.lean,Mathlib/Combinatorics/SimplicialComplex/FacePoset.lean,Mathlib/Combinatorics/SimplicialComplex/Hom.lean	5	2	['github-actions', 'mathlib4-merge-conflict-bot']	awainverse assignee:awainverse	154-26387 5 months ago	154-26388 154 days ago	99-48372 99 days
28871	JaafarTanoukhi author:JaafarTanoukhi	feat(Combinatorics/Digraph): Tournaments	Define orientations and tournaments. Related to #26771. Co-authored-by: Rida Hamadani --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-combinatorics new-contributor	62/0	Mathlib.lean,Mathlib/Combinatorics/Digraph/Orientation.lean,Mathlib/Combinatorics/Digraph/Tournament.lean	3	6	['JaafarTanoukhi', 'Rida-Hamadani', 'SnirBroshi', 'github-actions', 'mathlib4-merge-conflict-bot']	kmill assignee:kmill	154-26234 5 months ago	154-26235 154 days ago	55-54921 55 days
29526	llllvvuu author:llllvvuu	feat: `Multiset.map f` identifies `f` up to permutation	Motivation: Reason about `Fintype`-indexed families via `Multiset` equality. Example use case 1: ```lean theorem Matrix.IsHermitian.cfc_eigenvalues {d : Type} [Fintype d] [DecidableEq d] {M : Matrix d d 𝕜} (hM : M.IsHermitian) (f : ℝ → ℝ) (hcfc : Matrix.IsHermitian (cfc f M) := cfc_predicate f M) : ∃ (e : d ≃ d), hcfc.eigenvalues = f ∘ hM.eigenvalues ∘ e := by have := hcfc.roots_charpoly_eq_eigenvalues.symm rw [hM.charpoly_cfc_eq f, Polynomial.roots_prod] at this; swap · simp [Finset.prod_ne_zero_iff, Polynomial.X_sub_C_ne_zero] simp_rw [Polynomial.roots_X_sub_C, Multiset.bind_singleton] at this have he := (Multiset.compTriple_equivOfMapUnivEq this).comp_eq simp_rw [← Function.comp_def RCLike.ofReal, ← Function.comp_def f, Function.comp_assoc] at he exact ⟨_, RCLike.ofReal_injective.comp_left he.symm⟩ ``` Example use case 2 (on top of https://github.com/leanprover-community/mathlib4/pull/29610): ```lean theorem LinearMap.Eigenbasis.μ_equiv {ι ι' R G : Type} [Fintype ι] [Fintype ι'] [CommRing R] [IsDomain R] [AddCommGroup G] [Module R G] [Module.Free R G] [Module.Finite R G] {f : Module.End R G} (B₁ : f.Eigenbasis ι) (B₂ : f.Eigenbasis ι') : ∃ e : ι ≃ ι', B₁.μ = B₂.μ ∘ e := by classical have := congr(Polynomial.roots $(B₁.charpoly_eq.symm.trans B₂.charpoly_eq)) rw [Polynomial.roots_prod, Polynomial.roots_prod] at this; rotate_left · simp [Finset.prod_ne_zero_iff, Polynomial.X_sub_C_ne_zero] · simp [Finset.prod_ne_zero_iff, Polynomial.X_sub_C_ne_zero] simp_rw [Polynomial.roots_X_sub_C, Multiset.bind_singleton] at this exact ⟨Multiset.equivOfMapUnivEq this, (Multiset.compTriple_equivOfMapUnivEq this).comp_eq.symm⟩ ``` Co-authored-by: Aristotle Harmonic --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-data	35/0	Mathlib/Data/Multiset/Fintype.lean	1	9	['Ruben-VandeVelde', 'github-actions', 'llllvvuu', 'mathlib4-merge-conflict-bot', 'vihdzp', 'wwylele']	pechersky assignee:pechersky	154-26196 5 months ago	154-26197 154 days ago	69-16483 69 days
29947	JaafarTanoukhi author:JaafarTanoukhi	feat(Combinatorics/Digraph): Maps	Ported `SimpleGraph/Maps.lean` to `Digraph/Maps.lean` for future PRs related to issue #[26771](https://github.com/leanprover-community/mathlib4/issues/26771) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-combinatorics new-contributor	476/0	Mathlib.lean,Mathlib/Combinatorics/Digraph/Maps.lean	2	2	['github-actions', 'mathlib4-merge-conflict-bot']	awainverse assignee:awainverse	154-25600 5 months ago	154-25601 154 days ago	54-81855 54 days
31356	adomani author:adomani	feat: add inspect-like functions	Produces a tree-like formatting for `Syntax`, `Expr` and `InfoTree`. Especially for the `InfoTree`s, there are many parts of it that do not get printed. For instance, this is how the `InfoTree`s of `set_option linter.missingDocs true` get printed: ```lean inspectIT set_option linter.missingDocs true /- commandCtx \|-Info.ofCommandInfo: Lean.Elab.Command.elabSetOption, 'set_option…gDocs true' \| \|-Info.ofCompletionInfo.CompletionInfo.option 'set_option…issingDocs' \| \|-Info.ofOptionInfo: linter.missingDocs, Linter.linter.missingDocs -/ ``` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-meta	720/0	Mathlib.lean,Mathlib/Util/Inspect.lean,MathlibTest/Inspect.lean	3	3	['github-actions', 'mathlib4-merge-conflict-bot', 'plp127']	kim-em assignee:kim-em	154-20621 5 months ago	154-20622 154 days ago	11-59965 11 days
26890	robin-carlier author:robin-carlier	feat(CategoryTheory/Monoidal/DayConvolution): more API for `DayFunctor`	We provide some lemmas that helps characterizing the monoidal structure on `DayFunctor`, they are special cases of the lemmas for `LawfulDayConvolutionMonoidalCategoryStruct`. --- - [x] depends on: #26824 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-category-theory	1372/19	Mathlib.lean,Mathlib/CategoryTheory/Functor/KanExtension/Basic.lean,Mathlib/CategoryTheory/Monoidal/DayConvolution.lean,Mathlib/CategoryTheory/Monoidal/DayConvolution/DayFunctor.lean	4	5	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	153-85248 5 months ago	unknown	unknown
26912	pechersky author:pechersky	chore(Algebra/Ring/Subring): simp tag `Subring.smul_def`	s-multiplying by a subtype is easiest to manipulate when both terms are in the ambient type. Many places that had to use the _def lemma for a rewrite, or to include it in a simp set, no longer have to. Ported from #25308 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) I found this being not-simp frustrating when talking about submodules over a valuation subring.	merge-conflict t-algebra label:t-algebra$	67/66	Mathlib/Algebra/Algebra/Subalgebra/Basic.lean,Mathlib/Algebra/Field/Subfield/Basic.lean,Mathlib/Algebra/Group/Subgroup/Actions.lean,Mathlib/Algebra/Group/Submonoid/MulAction.lean,Mathlib/Algebra/Module/LocalizedModule/Basic.lean,Mathlib/Algebra/Module/LocalizedModule/Exact.lean,Mathlib/Algebra/Module/LocalizedModule/IsLocalization.lean,Mathlib/Algebra/Module/LocalizedModule/Submodule.lean,Mathlib/Algebra/Ring/Periodic.lean,Mathlib/Algebra/Ring/Subring/Basic.lean,Mathlib/Algebra/Ring/Subsemiring/Basic.lean,Mathlib/Analysis/CStarAlgebra/Basic.lean,Mathlib/FieldTheory/KummerExtension.lean,Mathlib/GroupTheory/GroupAction/Defs.lean,Mathlib/GroupTheory/GroupAction/MultiplePrimitivity.lean,Mathlib/GroupTheory/GroupAction/MultipleTransitivity.lean,Mathlib/GroupTheory/GroupAction/SubMulAction/OfFixingSubgroup.lean,Mathlib/GroupTheory/GroupAction/SubMulAction/OfStabilizer.lean,Mathlib/LinearAlgebra/RootSystem/Irreducible.lean,Mathlib/LinearAlgebra/RootSystem/WeylGroup.lean,Mathlib/RingTheory/Etale/Kaehler.lean,Mathlib/RingTheory/Ideal/Over.lean,Mathlib/RingTheory/LocalProperties/Projective.lean,Mathlib/RingTheory/Localization/InvSubmonoid.lean,Mathlib/RingTheory/OreLocalization/Basic.lean	25	26	['artie2000', 'eric-wieser', 'github-actions', 'j-loreaux', 'kckennylau', 'leanprover-bot', 'leanprover-radar', 'linesthatinterlace', 'mathlib4-merge-conflict-bot', 'pechersky']	joelriou assignee:joelriou	127-58399 4 months ago	149-7948 149 days ago	60-49993 60 days
30375	sinhp author:sinhp	feat(CategoryTheory): Basics of Locally Cartesian Closed Categories	Supersedes https://github.com/leanprover-community/mathlib4/pull/22321 This PR defines locally cartesian closed categories in terms of existence of the pushforward functors (right adjoint to the pullback functor) for all morphisms. We develop basic API and prove the following: 1. Existence of the pushforward functors is equivalent to cartesian closed slices. 2. Any locally cartesian closed category with a terminal object is cartesian closed. 3. The slices of a locally cartesian closed category are locally cartesian closed. --- - [ ] depends on: #31033 - [ ] depends on: #30373 - [ ] depends on: #31332 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-category-theory merge-conflict	703/0	Mathlib.lean,Mathlib/CategoryTheory/LocallyCartesianClosed/Basic.lean,Mathlib/CategoryTheory/LocallyCartesianClosed/ChosenPullbacksAlong.lean,Mathlib/CategoryTheory/LocallyCartesianClosed/ExponentiableMorphism.lean,Mathlib/CategoryTheory/LocallyCartesianClosed/Sections.lean	5	9	['Jlh18', 'github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'sinhp']	nobody	106-79800 3 months ago	unknown	unknown
33126	CoolRmal author:CoolRmal	feat: function composition preserves boundedness	This PR adds the following theorem: if the range of a function `g` is bounded above, then `g ∘ f` is bounded above for all functions `f`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-order merge-conflict	12/0	Mathlib/Order/Bounds/Basic.lean	1	2	['github-actions', 'mathlib4-merge-conflict-bot']	bryangingechen assignee:bryangingechen	96-2851 3 months ago	96-2852 96 days ago	27-2736 27 days
29587	uniwuni author:uniwuni	feat(GroupTheory/Finiteness): define finitely generated semigroups	We define finitely generated semigroups and basics similarly to monoids and groups and prove that semigroups and monoids remain finitely generated when a congruence is quotiented out. This will be important when further developing semigroup theory. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-group-theory	259/14	Mathlib/Algebra/Group/Submonoid/Defs.lean,Mathlib/GroupTheory/Finiteness.lean	2	4	['github-actions', 'mathlib4-merge-conflict-bot', 'plp127', 'uniwuni']	dupuisf assignee:dupuisf	94-14420 3 months ago	196-19324 196 days ago	25-73895 25 days
29014	ShreckYe author:ShreckYe	feat(Data/List/Scan): some theorems that relate `scanl` with `foldl`	I am not sure which is the best form of `getElem_scanl_eq_foldl_take` here, so I added several alternative forms. Feel free to remove any of them if necessary.	merge-conflict t-data	35/0	Mathlib/Data/List/Scan.lean	1	15	['ShreckYe', 'github-actions', 'mathlib4-merge-conflict-bot', 'themathqueen', 'vlad902']	pechersky assignee:pechersky	89-80044 2 months ago	163-45089 163 days ago	74-48754 74 days
9820	jjaassoonn author:jjaassoonn	feat(RingTheory/GradedAlgebra/HomogeneousIdeal): generalize to homogeneous submodule	The definitions, constructions and theorems in `HomogeneousIdeal.lean` are generalized to a homogeneous submodules. So say $R$ is a ring and $M \cong \bigoplus_{i} M_i$ is an $R$-module. Then a homogeneous $R$-submodule of $M$ is an $R$-submodule $N$ such that for all $i$ and $n \in N$, $n_i \in N$. Note that this notion doesn't actually require $R$ to be graded and $M$ is a graded module. But for more interesting lemmas, we do need that $M$ is graded $R$-module. We bake the fact $R$ is graded into the definition of homogeneous submodule, otherwise, `CompleteLattice HomogeneousSubmodule` cannot find the order of synthesis (the proof depends on that $R$ is graded) All definitions/constructions/theorems have a copy for ideals as well, this is to make sure dot notation still works. The motivation of this generalization is graded quotient module --- - [x] depends on:#18728 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-ring-theory	516/185	Mathlib/Algebra/Module/GradedModule.lean,Mathlib/AlgebraicGeometry/ProjectiveSpectrum/Scheme.lean,Mathlib/AlgebraicGeometry/ProjectiveSpectrum/Topology.lean,Mathlib/RingTheory/GradedAlgebra/Homogeneous/Ideal.lean,Mathlib/RingTheory/GradedAlgebra/Homogeneous/Submodule.lean,Mathlib/RingTheory/GradedAlgebra/Radical.lean,scripts/nolints_prime_decls.txt	7	3	['github-actions', 'leanprover-community-bot-assistant']	nobody	72-20073 2 months ago	unknown	unknown
34931	eric-wieser author:eric-wieser	perf: make TensorProduct.lift irreducible with a unification hint	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	6/2	Mathlib/LinearAlgebra/TensorProduct/Basic.lean	1	7	['eric-wieser', 'github-actions', 'leanprover-radar', 'mathlib-merge-conflicts']	erdOne assignee:erdOne	68-74493 2 months ago	68-74494 68 days ago	5-64455 5 days
33020	FormulaRabbit81 author:FormulaRabbit81	chore(Topology): Deprecate file	--- - [x] depends on: #30851 deprecation [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology large-import merge-conflict	82/49	Mathlib/Topology/Compactness/HilbertCubeEmbedding.lean,Mathlib/Topology/MetricSpace/HausdorffAlexandroff.lean,Mathlib/Topology/MetricSpace/PiNat.lean	3	3	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	66-51104 2 months ago	125-38493 125 days ago	0-13670 3 hours
33281	michelsol author:michelsol	feat(Analysis/SpecialFunctions/Integrals): integral of 1/sqrt(1-x^2) and its integrability.	Add the integral of the derivative of arcsin and its integrability. --- - [ ] depends on: #33280 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor merge-conflict t-analysis	59/0	Mathlib/Analysis/SpecialFunctions/Integrability/Basic.lean,Mathlib/Analysis/SpecialFunctions/Integrals/Basic.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral/FundThmCalculus.lean	3	3	['github-actions', 'mathlib-dependent-issues', 'mathlib4-merge-conflict-bot']	nobody	66-19898 2 months ago	117-74123 117 days ago	0-811 13 minutes
34156	zcyemi author:zcyemi	feat(Analysis/Convex/Between): add lemmas on convex combination of mem simplex interior	--- I add three lemmas of convex combinations preserving membership in the interior of a simplex. And also open a zulip thread [#mathlib4 > Best place for convex combination and simplex interior](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Best.20place.20for.20convex.20combination.20and.20simplex.20interior/with/568558406) deps: - [ ] depends on: #33852	t-analysis merge-conflict	170/0	Mathlib/Analysis/Convex/Between.lean,Mathlib/LinearAlgebra/AffineSpace/Independent.lean	2	3	['github-actions', 'mathlib-dependent-issues', 'mathlib-merge-conflicts']	nobody	65-82215 2 months ago	65-82215 65 days ago	0-1236 20 minutes
25980	Multramate author:Multramate	refactor(Algebra/Group/Submonoid/Operations): rename restrict to domRestrict and add restrict	And update the documentation for consistency	t-group-theory merge-conflict	145/123	Mathlib/Algebra/Group/Subgroup/Basic.lean,Mathlib/Algebra/Group/Subgroup/Ker.lean,Mathlib/Algebra/Group/Submonoid/Operations.lean,Mathlib/GroupTheory/FiniteAbelian/Duality.lean,Mathlib/GroupTheory/MonoidLocalization/Basic.lean,Mathlib/GroupTheory/MonoidLocalization/Maps.lean,Mathlib/GroupTheory/MonoidLocalization/MonoidWithZero.lean,Mathlib/GroupTheory/PGroup.lean,Mathlib/GroupTheory/QuotientGroup/Basic.lean,Mathlib/GroupTheory/Transfer.lean,Mathlib/LinearAlgebra/RootSystem/WeylGroup.lean,Mathlib/NumberTheory/NumberField/CMField.lean,Mathlib/NumberTheory/NumberField/Ideal/Basic.lean,Mathlib/RingTheory/Localization/Defs.lean	14	10	['Multramate', 'copilot-pull-request-reviewer', 'github-actions', 'mathlib-merge-conflicts']	nobody	63-56343 2 months ago	63-56344 63 days ago	5-5910 5 days
25981	Multramate author:Multramate	feat(GroupTheory/GroupAction/Basic): define homomorphisms of fixed subgroups induced by homomorphisms of groups	This PR continues the work from #10126. Original PR: https://github.com/leanprover-community/mathlib4/pull/10126	t-group-theory large-import merge-conflict	218/144	Mathlib/Algebra/Group/Subgroup/Basic.lean,Mathlib/Algebra/Group/Subgroup/Ker.lean,Mathlib/Algebra/Group/Submonoid/Operations.lean,Mathlib/Algebra/Ring/Action/Submonoid.lean,Mathlib/GroupTheory/FiniteAbelian/Duality.lean,Mathlib/GroupTheory/GroupAction/Defs.lean,Mathlib/GroupTheory/MonoidLocalization/Basic.lean,Mathlib/GroupTheory/MonoidLocalization/Maps.lean,Mathlib/GroupTheory/MonoidLocalization/MonoidWithZero.lean,Mathlib/GroupTheory/PGroup.lean,Mathlib/GroupTheory/QuotientGroup/Basic.lean,Mathlib/GroupTheory/Transfer.lean,Mathlib/LinearAlgebra/RootSystem/WeylGroup.lean,Mathlib/NumberTheory/NumberField/CMField.lean,Mathlib/NumberTheory/NumberField/Ideal/Basic.lean,Mathlib/RingTheory/Localization/Defs.lean	16	8	['copilot-pull-request-reviewer', 'github-actions', 'mathlib-merge-conflicts']	nobody	63-56342 2 months ago	63-56342 63 days ago	4-72754 4 days
33795	alreadydone author:alreadydone	feat(Topology/Sheaves): LocalPredicate prerequisite for étalé spaces	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology merge-conflict	418/143	Mathlib/AlgebraicGeometry/ProjectiveSpectrum/StructureSheaf.lean,Mathlib/Geometry/Manifold/Sheaf/Smooth.lean,Mathlib/Logic/Equiv/Basic.lean,Mathlib/Topology/Sheaves/LocalPredicate.lean,Mathlib/Topology/Sheaves/Sheafify.lean,Mathlib/Topology/Sheaves/Stalks.lean	6	12	['adamtopaz', 'alreadydone', 'dagurtomas', 'github-actions', 'mathlib-merge-conflicts']	adamtopaz assignee:adamtopaz	63-33976 2 months ago	63-33977 63 days ago	34-7368 34 days
34674	Citronhat author:Citronhat	feat(Algebra/Order/Ring): replace ENNReal lemmas with WithTop versions	* Add `WithTop` versions of basic multiplicative order lemmas. * Use the new `WithTop` lemmas to replace `ENNReal` proofs and address six TODOs. * Fix a typo in the `pos_of_ne_zero` alias name.	new-contributor t-algebra merge-conflict label:t-algebra$	46/15	Mathlib/Algebra/Order/Monoid/Canonical/Defs.lean,Mathlib/Algebra/Order/Ring/WithTop.lean,Mathlib/Data/ENNReal/Operations.lean	3	5	['Citronhat', 'Ruben-VandeVelde', 'github-actions', 'mathlib-merge-conflicts']	Ruben-VandeVelde assignee:Ruben-VandeVelde	63-13846 2 months ago	63-13847 63 days ago	16-81273 16 days
33746	ster-oc author:ster-oc	feat(Algebra/Module/ZLattice): align `ZSpan.floor` to `Int.floor` API	This PR adds some of the existent lemmas about `Int.floor`, `Int.ceil` and `Int.fract` to the `ZSpan` namespace. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra new-contributor merge-conflict label:t-algebra$	353/145	Mathlib/Algebra/Module/ZLattice/Basic.lean,Mathlib/Algebra/Order/Floor/Ring.lean,Mathlib/Topology/Algebra/Order/Floor.lean	3	8	['github-actions', 'joelriou', 'mathlib-merge-conflicts', 'ster-oc']	joelriou assignee:joelriou	58-30744 1 month ago	58-30744 58 days ago	30-19397 30 days
33791	PhoenixIra author:PhoenixIra	feat: Generalization of FixedPointApproximants to CompletePartialOrder	--- This PR provides a generalization of FixedPointApproximants to CompletePartialOrder. Not every theorem can be generalized, as sometimes we require additional conditions (namely `x ≤ f x`) in order to guarantee that the set is directed and thus the supremum is well-defined. This is not necessary in a CompleteLattice. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-order merge-conflict	223/100	Mathlib/Order/CompletePartialOrder.lean,Mathlib/SetTheory/Ordinal/FixedPointApproximants.lean	2	21	['PhoenixIra', 'github-actions', 'mathlib-merge-conflicts', 'vihdzp']	PhoenixIra and vihdzp assignee:PhoenixIra assignee:vihdzp	53-67478 1 month ago	53-67478 53 days ago	38-8977 38 days
26942	pechersky author:pechersky	feat(RingTheory/Valuation/ValueGroupIso): isomorphism of value groups when compatible	and also to the ValuativeRel's value group by request from comment in https://github.com/leanprover-community/mathlib4/pull/26754#issuecomment-3051770901 - [ ] depends on: #26588 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) - [x] depends on: #26939 - [x] depends on: #26940 - [x] depends on: #26941	merge-conflict t-ring-theory t-order	299/3	Mathlib.lean,Mathlib/Algebra/GroupWithZero/Range.lean,Mathlib/Algebra/Order/GroupWithZero/Range.lean,Mathlib/Algebra/Order/GroupWithZero/WithZero.lean,Mathlib/Algebra/Order/Monoid/WithTop.lean,Mathlib/RingTheory/Valuation/ValueGroupIso.lean	6	10	['faenuccio', 'github-actions', 'mathlib-dependent-issues', 'mathlib4-merge-conflict-bot', 'pechersky']	faenuccio assignee:faenuccio	51-11659 1 month ago	250-85374 250 days ago	10-59532 10 days
27534	PierreQuinton author:PierreQuinton	feat: a typeclass for `sSup`/`sInf` to be lawful	Adds lawful infima and suprema type classes. A preorder with lawful suprema: whenever a set has a least upper bound, `sSup` returns a least upper bound for that set. A preorder with lawful infima: whenever a set has a greatest lower bound, `sInf` returns a greastest lower bound for that set. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-order	121/8	Mathlib.lean,Mathlib/Order/CompleteLattice/Defs.lean,Mathlib/Order/LawfulSupInf.lean	3	26	['PierreQuinton', 'YaelDillies', 'github-actions', 'mathlib4-merge-conflict-bot', 'plp127', 'vihdzp']	nobody	38-81855 1 month ago	154-26530 154 days ago	114-33795 114 days
35042	JovanGerb author:JovanGerb	chore: remove `meta` form `import Mathlib.Tactic...`	This PR cleans up some imports of the form `import Mathlib.Tactic...`, by either removing them entirely, or removing the `meta` keyword. It should never be necessary to `meta import` a file from `Mathlib.Tactic`, because the relevant definitions should already have been marked as `meta`. The motivation is to reduce the amount of files that are `meta` imported when writing e.g. `import Mathlib`, hence reducing the amount of stuff that needs to be loaded. There are more other `meta import`s that need to be removed, but this PR is a good start. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import merge-conflict	61/142	Mathlib/Algebra/BigOperators/Group/Finset/Defs.lean,Mathlib/Algebra/FreeMonoid/Basic.lean,Mathlib/Algebra/Group/Action/Hom.lean,Mathlib/Algebra/Order/Group/Unbundled/Abs.lean,Mathlib/CategoryTheory/Functor/Basic.lean,Mathlib/Data/List/ChainOfFn.lean,Mathlib/Dynamics/OmegaLimit.lean,Mathlib/GroupTheory/GroupAction/Defs.lean,Mathlib/GroupTheory/GroupAction/DomAct/Basic.lean,Mathlib/Tactic/Algebraize.lean,Mathlib/Tactic/ApplyFun.lean,Mathlib/Tactic/ArithMult.lean,Mathlib/Tactic/Bound.lean,Mathlib/Tactic/CategoryTheory/Bicategory/Datatypes.lean,Mathlib/Tactic/CategoryTheory/Bicategory/Normalize.lean,Mathlib/Tactic/CategoryTheory/Bicategory/PureCoherence.lean,Mathlib/Tactic/CategoryTheory/CheckCompositions.lean,Mathlib/Tactic/CategoryTheory/Coherence/Basic.lean,Mathlib/Tactic/CategoryTheory/Coherence/Normalize.lean,Mathlib/Tactic/CategoryTheory/Coherence/PureCoherence.lean,Mathlib/Tactic/CategoryTheory/Elementwise.lean,Mathlib/Tactic/CategoryTheory/Monoidal/Datatypes.lean,Mathlib/Tactic/CategoryTheory/Monoidal/Normalize.lean,Mathlib/Tactic/CategoryTheory/Monoidal/PureCoherence.lean,Mathlib/Tactic/CategoryTheory/ToApp.lean,Mathlib/Tactic/Choose.lean,Mathlib/Tactic/DeclarationNames.lean,Mathlib/Tactic/DefEqTransformations.lean,Mathlib/Tactic/DeriveCountable.lean,Mathlib/Tactic/DeriveFintype.lean,Mathlib/Tactic/DeriveTraversable.lean,Mathlib/Tactic/ENatToNat.lean,Mathlib/Tactic/Explode.lean,Mathlib/Tactic/Explode/Pretty.lean,Mathlib/Tactic/FinCases.lean,Mathlib/Tactic/FunProp.lean,Mathlib/Tactic/FunProp/Attr.lean,Mathlib/Tactic/FunProp/Core.lean,Mathlib/Tactic/FunProp/FunctionData.lean,Mathlib/Tactic/FunProp/Theorems.lean,Mathlib/Tactic/FunProp/Types.lean,Mathlib/Tactic/GCongr/Core.lean,Mathlib/Tactic/GRewrite/Elab.lean,Mathlib/Tactic/Group.lean,Mathlib/Tactic/IrreducibleDef.lean,Mathlib/Tactic/Lift.lean,Mathlib/Tactic/Linarith.lean,Mathlib/Tactic/Linarith/Lemmas.lean,Mathlib/Tactic/Linarith/Oracle/FourierMotzkin.lean,Mathlib/Tactic/Linarith/Oracle/SimplexAlgorithm.lean,Mathlib/Tactic/Linarith/Oracle/SimplexAlgorithm/Gauss.lean,Mathlib/Tactic/Linarith/Oracle/SimplexAlgorithm/SimplexAlgorithm.lean,Mathlib/Tactic/Linarith/Preprocessing.lean,Mathlib/Tactic/Linarith/Verification.lean,Mathlib/Tactic/LinearCombination/Lemmas.lean,Mathlib/Tactic/Linter/DeprecatedSyntaxLinter.lean,Mathlib/Tactic/Linter/DocPrime.lean,Mathlib/Tactic/Linter/DocString.lean,Mathlib/Tactic/Linter/EmptyLine.lean,Mathlib/Tactic/Linter/FlexibleLinter.lean,Mathlib/Tactic/Linter/GlobalAttributeIn.lean,Mathlib/Tactic/Linter/HashCommandLinter.lean,Mathlib/Tactic/Linter/Multigoal.lean,Mathlib/Tactic/Linter/OldObtain.lean,Mathlib/Tactic/Linter/Style.lean,Mathlib/Tactic/Linter/TextBased.lean,Mathlib/Tactic/Linter/TextBased/UnicodeLinter.lean,Mathlib/Tactic/Linter/UnusedTactic.lean,Mathlib/Tactic/Linter/UnusedTacticExtension.lean,Mathlib/Tactic/MinImports.lean,Mathlib/Tactic/MoveAdd.lean,Mathlib/Tactic/Nontriviality/Core.lean,Mathlib/Tactic/NormNum/DivMod.lean,Mathlib/Tactic/NormNum/Ineq.lean,Mathlib/Tactic/NormNum/Prime.lean,Mathlib/Tactic/Order.lean,Mathlib/Tactic/Order/CollectFacts.lean,Mathlib/Tactic/Order/Graph/Tarjan.lean,Mathlib/Tactic/PNatToNat.lean,Mathlib/Tactic/Peel.lean,Mathlib/Tactic/ProdAssoc.lean,Mathlib/Tactic/ProxyType.lean,Mathlib/Tactic/Push.lean,Mathlib/Tactic/Qify.lean,Mathlib/Tactic/RSuffices.lean,Mathlib/Tactic/Ring/Basic.lean,Mathlib/Tactic/Ring/Common.lean,Mathlib/Tactic/Ring/Compare.lean,Mathlib/Tactic/Ring/PNat.lean,Mathlib/Tactic/Simproc/Divisors.lean,Mathlib/Tactic/Simproc/FinsetInterval.lean,Mathlib/Tactic/Simps/Basic.lean,Mathlib/Tactic/Subsingleton.lean,Mathlib/Tactic/TacticAnalysis/Declarations.lean,Mathlib/Tactic/TautoSet.lean,Mathlib/Tactic/Translate/Core.lean,Mathlib/Tactic/Translate/TagUnfoldBoundary.lean,Mathlib/Tactic/Widget/Calc.lean,Mathlib/Tactic/Widget/CommDiag.lean,Mathlib/Tactic/Widget/CongrM.lean	107	9	['JovanGerb', 'dupuisf', 'github-actions', 'leanprover-radar', 'mathlib-merge-conflicts']	robin-carlier assignee:robin-carlier	37-24000 1 month ago	37-24001 37 days ago	26-54241 26 days
35213	kim-em author:kim-em	chore: use @[to_dual] in ConditionallyCompleteLattice	This PR adds `@[to_dual]` annotations across all `ConditionallyCompleteLattice` files: `Defs`, `Basic`, `Indexed`, `Finset`, and `Group`. Auto-generates dual theorems and deletes hand-written versions. (Absorbs the former PR #35212.) [Diff relative to #35209](https://github.com/kim-em/mathlib4/compare/kim/to-dual-complete-lattice...kim/to-dual-ccl-extended) - [ ] depends on: #35209 - [ ] depends on: #35211 🤖 Prepared with Claude Code	merge-conflict LLM-generated	189/485	Mathlib/Order/Bounds/Basic.lean,Mathlib/Order/CompleteLattice/Basic.lean,Mathlib/Order/CompleteLattice/Defs.lean,Mathlib/Order/ConditionallyCompleteLattice/Defs.lean	4	5	['github-actions', 'mathlib-dependent-issues', 'mathlib-merge-conflicts']	nobody	32-85590 1 month ago	unknown	unknown
35210	kim-em author:kim-em	chore: use @[to_dual] in CompleteLattice extras and Set.Lattice	This PR uses `@[to_dual]` to auto-generate dual theorems in `Order.CompleteLattice.Lemmas`, `Order.CompleteLattice.Finset`, and `Data.Set.Lattice`, deleting hand-written dual versions. [Diff relative to previous PR](https://github.com/kim-em/mathlib4/compare/kim/to-dual-complete-lattice...kim/to-dual-complete-lattice-extras) - [ ] depends on: #35209 🤖 Prepared with Claude Code	merge-conflict LLM-generated	217/579	Mathlib/Data/Set/Lattice.lean,Mathlib/Order/Bounds/Basic.lean,Mathlib/Order/CompleteLattice/Basic.lean,Mathlib/Order/CompleteLattice/Defs.lean,Mathlib/Order/CompleteLattice/Finset.lean,Mathlib/Order/CompleteLattice/Lemmas.lean,Mathlib/Tactic/SetLike.lean	7	5	['github-actions', 'mathlib-dependent-issues', 'mathlib-merge-conflicts']	nobody	32-85587 1 month ago	unknown	unknown
35215	kim-em author:kim-em	chore: use @[to_dual] in FixedPoints	This PR adds `@[to_dual]` annotations to 14 theorems about `lfp` in `Order/FixedPoints.lean`, auto-generating their `gfp` duals and deleting the hand-written versions. Also registers `OrderHom.lfp` as the dual of `OrderHom.gfp` via `attribute [to_dual existing]`. Auto-generated duals include: `le_gfp`, `gfp_le_fixed`, `gfp_le`, `gfp_le_map`, `map_gfp`, `isFixedPt_gfp`, `map_le_gfp`, `isGreatest_gfp_le`, `isGreatest_gfp`, `gfp_induction`, `map_gfp_comp`, `gfp_gfp`, `map_inf_fixedPoints_le`, `map_sInf_subset_fixedPoints_le`. [Diff relative to #35208](https://github.com/kim-em/mathlib4/compare/kim/to-dual-bounds-basic...kim/to-dual-fixed-points) - [x] depends on: #35208 🤖 Prepared with Claude Code	LLM-generated merge-conflict	249/548	Mathlib/Algebra/Module/Torsion/Basic.lean,Mathlib/Order/CompleteLattice/Basic.lean,Mathlib/Order/CompleteLattice/Defs.lean,Mathlib/Order/ConditionallyCompleteLattice/Defs.lean,Mathlib/Order/FixedPoints.lean,Mathlib/Order/GaloisConnection/Basic.lean,Mathlib/Order/Interval/Set/Disjoint.lean,Mathlib/Topology/Order.lean	8	11	['JovanGerb', 'github-actions', 'kim-em', 'mathlib-dependent-issues', 'mathlib-merge-conflicts', 'vihdzp']	alexjbest assignee:alexjbest	32-80827 1 month ago	32-80828 32 days ago	24-10 24 days
32918	michelsol author:michelsol	feat: define `supEdist` and `supDist`	Create a new file Topology.MetricSpace.SupDistance and define the supremal distance in (extended) metric spaces. The defined `supEdist` and `supDist` will have similar theory to the already existing `infEdist` and `infDist`. The motivation is to be able to define the radius of a minimal bounding sphere as the infimum of the supDist later. [zulip discussion here](https://leanprover.zulipchat.com/#narrow/channel/116395-maths/topic/Formalizing.20Jung's.20theorem.20and.20minimal.20bounding.20spheres)	t-topology new-contributor merge-conflict	75/0	Mathlib.lean,Mathlib/Topology/MetricSpace/SupDistance.lean	2	5	['github-actions', 'mathlib4-merge-conflict-bot', 'michelsol', 'urkud']	nobody	32-3822 1 month ago	106-68782 106 days ago	21-957 21 days
36165	Parcly-Taxel author:Parcly-Taxel	chore: deprecate `Nat.strongRec(On)'`	In favour of Batteries's `Nat.strongRec` for definitions and `Nat.strong_induction_on` for proofs.	t-data merge-conflict	34/66	Mathlib/Analysis/Analytic/Inverse.lean,Mathlib/Data/Int/GCD.lean,Mathlib/Data/Nat/Factorization/Induction.lean,Mathlib/Data/Nat/Init.lean,Mathlib/Data/Set/Finite/Basic.lean,Mathlib/Data/ZMod/Basic.lean,Mathlib/GroupTheory/SpecificGroups/Cyclic.lean,Mathlib/Topology/EMetricSpace/Paracompact.lean	8	6	['JovanGerb', 'MichaelStollBayreuth', 'Parcly-Taxel', 'Vierkantor', 'github-actions', 'mathlib-bors', 'mathlib-merge-conflicts']	Vierkantor assignee:Vierkantor	26-76951 26 days ago	32-80818 32 days ago	15-50927 15 days
37073	kim-em author:kim-em	feat: add normalize_instance% using core's normalizeInstance	This PR adds a new `normalize_instance%` term elaborator that delegates to Lean core's `normalizeInstance` (from https://github.com/leanprover/lean4/pull/12897), and replaces ~53 `fast_instance%` call sites where the replacement is safe. `normalize_instance%` is a thin wrapper (~15 lines) around `Lean.Meta.normalizeInstance`. Like `fast_instance%`, it reduces instances to constructor applications and reuses canonical sub-instances. Unlike `fast_instance%`, it works at `instances` transparency and delegates all normalization logic to core. The replaced sites cover: - Equiv/type-alias transfers (WithAbs, WithConv, WithVal, WithLp, TransferInstance) - Surjective constructors (Con, RingCon quotients, module congruences) - DFunLike leaf instances (MultilinearMap, ContinuousMultilinearMap, AlternatingMap, Intertwining) - Quotient instances (LinearAlgebra/Quotient/Defs) - inferInstanceAs% sites (StandardPart, Presentation/Core) - Miscellaneous (InfiniteAdeleRing, ZMod) This PR doesn't attempt to replace all `fast_instance%`; it gets more complicated! 🤖 Prepared with Claude Code	merge-conflict	88/59	Mathlib/Algebra/Algebra/TransferInstance.lean,Mathlib/Algebra/Module/Congruence/Defs.lean,Mathlib/Algebra/Order/Ring/StandardPart.lean,Mathlib/Algebra/WithConv.lean,Mathlib/Analysis/Normed/Lp/WithLp.lean,Mathlib/Analysis/Normed/Ring/WithAbs.lean,Mathlib/Data/ZMod/Basic.lean,Mathlib/GroupTheory/Congruence/Defs.lean,Mathlib/LinearAlgebra/Alternating/Basic.lean,Mathlib/LinearAlgebra/Multilinear/Basic.lean,Mathlib/LinearAlgebra/Quotient/Defs.lean,Mathlib/NumberTheory/NumberField/InfiniteAdeleRing.lean,Mathlib/RepresentationTheory/Intertwining.lean,Mathlib/RingTheory/Extension/Presentation/Core.lean,Mathlib/Tactic/FastInstance.lean,Mathlib/Topology/Algebra/Module/Alternating/Basic.lean,Mathlib/Topology/Algebra/Module/Multilinear/Basic.lean,Mathlib/Topology/Algebra/Valued/WithVal.lean	18	7	['JovanGerb', 'github-actions', 'kim-em', 'leanprover-radar', 'mathlib-merge-conflicts']	nobody	26-41402 26 days ago	26-41403 26 days ago	2-70173 2 days
31595	astrainfinita author:astrainfinita	chore: redefine `Ideal.IsPrime`	Redefine `Ideal.IsPrime` to make it correct for non-commutative cases --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	333/100	Mathlib/Algebra/Order/Ring/Ordering/Defs.lean,Mathlib/RingTheory/DedekindDomain/Ideal/Lemmas.lean,Mathlib/RingTheory/GradedAlgebra/Radical.lean,Mathlib/RingTheory/Ideal/AssociatedPrime/Basic.lean,Mathlib/RingTheory/Ideal/Maps.lean,Mathlib/RingTheory/Ideal/Maximal.lean,Mathlib/RingTheory/Ideal/MinimalPrime/Noetherian.lean,Mathlib/RingTheory/Ideal/Oka.lean,Mathlib/RingTheory/Ideal/Operations.lean,Mathlib/RingTheory/Ideal/Over.lean,Mathlib/RingTheory/Ideal/Pointwise.lean,Mathlib/RingTheory/Ideal/Prime.lean,Mathlib/RingTheory/Ideal/Prod.lean,Mathlib/RingTheory/Ideal/Quotient/Basic.lean,Mathlib/RingTheory/Ideal/Quotient/Operations.lean,Mathlib/RingTheory/IsPrimary.lean,Mathlib/RingTheory/Localization/AtPrime/Basic.lean,Mathlib/RingTheory/Localization/Ideal.lean,Mathlib/RingTheory/Polynomial/Basic.lean,Mathlib/RingTheory/PrincipalIdealDomain.lean,Mathlib/RingTheory/Spectrum/Prime/Topology.lean,Mathlib/RingTheory/Valuation/Basic.lean	22	33	['alreadydone', 'artie2000', 'astrainfinita', 'erdOne', 'github-actions', 'leanprover-bot', 'leanprover-radar', 'mathlib-merge-conflicts', 'mathlib4-merge-conflict-bot']	kim-em assignee:kim-em	24-36961 24 days ago	24-36962 24 days ago	59-56691 59 days
35415	joneugster author:joneugster	feat(Cache): enable partial cache in downstream projects	Migrated to fork from: #21238. Add features to `cache` and cleanup code: * enable partial cache retrieval in downstream projects: `lake exe cache get MyProject.Basic` downloads only the relevant cache to build `MyProject/Basic.lean` --- ### Notes: - replaces: #21195 - should address: #8767 - should address: #20568 ### Completed: - [x] depends on: #21632 - [x] ~~depends on: #21663~~ - [x] depends on: #21666 - [x] depends on: #21701 - [x] depends on: #21703 - [x] depends on: #21704 - [x] depends on: #21705 - [x] depends on: #21707 - [x] depends on: #21711 - [x] depends on: #21750 - [x] depends on: #21815 - [x] depends on: #21816 - [x] depends on: #21817 - [x] depends on: #21818 - [x] depends on: #21822 - [x] depends on: #21830 - [x] depends on: #21848 - [x] depends on: #21834 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	CI t-meta merge-conflict	34/15	Cache/Hashing.lean,Cache/IO.lean,Cache/Main.lean	3	4	['github-actions', 'mathlib-dependent-issues', 'mathlib-merge-conflicts']	nobody	22-30626 22 days ago	22-30627 22 days ago	31-57408 31 days
37502	felixpernegger author:felixpernegger	refactor(Topology): rename ```LocPathConnected```	Rename ```LocPathConnected``` to ```LocallyPathConnected``` per discussion at https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Rename.20.60.60.60LocPathConnectedSpace.60.60.60.3F/with/582824006 Deprecations were partly added with Claude --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology merge-conflict	369/304	Mathlib.lean,Mathlib/Analysis/CStarAlgebra/Unitary/Connected.lean,Mathlib/Analysis/Complex/UpperHalfPlane/Topology.lean,Mathlib/Geometry/Manifold/ChartedSpace.lean,Mathlib/Geometry/Manifold/Instances/Real.lean,Mathlib/Topology/Algebra/Module/LocallyConvex.lean,Mathlib/Topology/Compactness/DeltaGeneratedSpace.lean,Mathlib/Topology/Connected/LocPathConnected.lean,Mathlib/Topology/Connected/LocallyPathConnected.lean,Mathlib/Topology/Connected/PathComponentOne.lean,Mathlib/Topology/Homotopy/Lifting.lean,Mathlib/Topology/Homotopy/LocallyContractible.lean	12	8	['SnirBroshi', 'felixpernegger', 'github-actions', 'mathlib-bors', 'mathlib-merge-conflicts']	j-loreaux assignee:j-loreaux	20-4584 20 days ago	20-16972 20 days ago	0-65765 18 hours
33434	astrainfinita author:astrainfinita	chore: redefine `Finsupp.indicator` using `Finsupp.onFinset`	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data merge-conflict	6/17	Mathlib/Data/Finsupp/Indicator.lean	1	2	['github-actions', 'mathlib-merge-conflicts']	nobody	12-68493 12 days ago	12-68494 12 days ago	5-30293 5 days
35802	xroblot author:xroblot	feat(RamificationInertia): splitting in the decomposition field	--- - [x] depends on: #35798 - [ ] depends on: #35405 - [x] depends on: #35371 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-number-theory large-import merge-conflict	279/4	Mathlib/NumberTheory/RamificationInertia/Basic.lean,Mathlib/NumberTheory/RamificationInertia/HilbertTheory.lean,Mathlib/RingTheory/FiniteType.lean,Mathlib/RingTheory/Finiteness/Basic.lean	4	5	['github-actions', 'joneugster', 'mathlib-dependent-issues', 'mathlib-merge-conflicts']	nobody	11-86309 11 days ago	unknown	unknown
37793	YaelDillies author:YaelDillies	chore: camel-case `finset_sum` in lemma names	and `finset_prod` too. Done with grep with the bogus replacements reverted by hand. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	866/530	Mathlib/Algebra/Algebra/Operations.lean,Mathlib/Algebra/Algebra/Subalgebra/Operations.lean,Mathlib/Algebra/BigOperators/Associated.lean,Mathlib/Algebra/BigOperators/Fin.lean,Mathlib/Algebra/BigOperators/Finprod.lean,Mathlib/Algebra/BigOperators/Finsupp/Basic.lean,Mathlib/Algebra/BigOperators/Group/Finset/Defs.lean,Mathlib/Algebra/BigOperators/Group/Finset/Lemmas.lean,Mathlib/Algebra/BigOperators/Pi.lean,Mathlib/Algebra/DirectSum/Basic.lean,Mathlib/Algebra/DirectSum/Idempotents.lean,Mathlib/Algebra/DirectSum/Internal.lean,Mathlib/Algebra/Group/EvenFunction.lean,Mathlib/Algebra/Group/ForwardDiff.lean,Mathlib/Algebra/Group/Pointwise/Set/BigOperators.lean,Mathlib/Algebra/Group/Subgroup/Finite.lean,Mathlib/Algebra/Group/Submonoid/BigOperators.lean,Mathlib/Algebra/Lie/Loop.lean,Mathlib/Algebra/LinearRecurrence.lean,Mathlib/Algebra/Module/LocalizedModule/Int.lean,Mathlib/Algebra/Module/Submodule/LinearMap.lean,Mathlib/Algebra/Module/Submodule/Pointwise.lean,Mathlib/Algebra/Module/Torsion/Basic.lean,Mathlib/Algebra/MonoidAlgebra/Degree.lean,Mathlib/Algebra/MonoidAlgebra/MapDomain.lean,Mathlib/Algebra/MvPolynomial/Basic.lean,Mathlib/Algebra/MvPolynomial/Degrees.lean,Mathlib/Algebra/Order/Antidiag/Nat.lean,Mathlib/Algebra/Order/BigOperators/Group/Finset.lean,Mathlib/Algebra/Polynomial/BigOperators.lean,Mathlib/Algebra/Polynomial/Bivariate.lean,Mathlib/Algebra/Polynomial/Coeff.lean,Mathlib/Algebra/Polynomial/EraseLead.lean,Mathlib/Algebra/Polynomial/Eval/Defs.lean,Mathlib/Algebra/Polynomial/Eval/Degree.lean,Mathlib/Algebra/Polynomial/Expand.lean,Mathlib/Algebra/Polynomial/FieldDivision.lean,Mathlib/Algebra/Polynomial/HasseDeriv.lean,Mathlib/Algebra/Polynomial/Lifts.lean,Mathlib/Algebra/Polynomial/SumIteratedDerivative.lean,Mathlib/AlgebraicGeometry/ProjectiveSpectrum/Proper.lean,Mathlib/AlgebraicGeometry/SpreadingOut.lean,Mathlib/Analysis/CStarAlgebra/ApproximateUnit.lean,Mathlib/Analysis/CStarAlgebra/ContinuousFunctionalCalculus/NonUnital.lean,Mathlib/Analysis/CStarAlgebra/ContinuousFunctionalCalculus/Unital.lean,Mathlib/Analysis/Calculus/ContDiff/FaaDiBruno.lean,Mathlib/Analysis/Calculus/Deriv/Mul.lean,Mathlib/Analysis/Calculus/FDeriv/Analytic.lean,Mathlib/Analysis/Calculus/FDeriv/Mul.lean,Mathlib/Analysis/Calculus/LogDeriv.lean,Mathlib/Analysis/Calculus/Rademacher.lean,Mathlib/Analysis/Calculus/Taylor.lean,Mathlib/Analysis/Distribution/SchwartzSpace/Deriv.lean,Mathlib/Analysis/Fourier/AddCircle.lean,Mathlib/Analysis/Fourier/FourierTransformDeriv.lean,Mathlib/Analysis/LocallyConvex/WithSeminorms.lean,Mathlib/Analysis/MeanInequalities.lean,Mathlib/Analysis/MeanInequalitiesPow.lean,Mathlib/Analysis/Normed/Field/Approximation.lean,Mathlib/Analysis/Normed/Group/FunctionSeries.lean,Mathlib/Analysis/Normed/Group/Tannery.lean,Mathlib/Analysis/Normed/Group/Ultra.lean,Mathlib/Analysis/Normed/Lp/lpSpace.lean,Mathlib/Analysis/Normed/Module/FiniteDimension.lean,Mathlib/Analysis/Normed/Ring/InfiniteProd.lean,Mathlib/Analysis/Normed/Ring/InfiniteSum.lean,Mathlib/Analysis/Normed/Unbundled/FiniteExtension.lean,Mathlib/Analysis/SpecialFunctions/Log/Summable.lean,Mathlib/Analysis/SpecialFunctions/Pochhammer.lean,Mathlib/Analysis/SpecialFunctions/Pow/NNReal.lean,Mathlib/Analysis/SpecialFunctions/Pow/Real.lean,Mathlib/Analysis/SpecialFunctions/Trigonometric/Chebyshev/ChebyshevGauss.lean,Mathlib/Analysis/SpecialFunctions/Trigonometric/Chebyshev/RootsExtrema.lean,Mathlib/Analysis/SpecificLimits/Normed.lean,Mathlib/Combinatorics/Hindman.lean,Mathlib/Combinatorics/SimpleGraph/LapMatrix.lean,Mathlib/Computability/AkraBazzi/SumTransform.lean,Mathlib/Data/DFinsupp/BigOperators.lean,Mathlib/Data/ENNReal/BigOperators.lean,Mathlib/Data/Finsupp/Basic.lean,Mathlib/Data/Nat/Choose/Lucas.lean,Mathlib/Data/Nat/Factorization/Basic.lean,Mathlib/Data/Nat/Squarefree.lean,Mathlib/Data/ZMod/Units.lean,Mathlib/FieldTheory/ChevalleyWarning.lean,Mathlib/FieldTheory/IntermediateField/Basic.lean,Mathlib/FieldTheory/Minpoly/MinpolyDiv.lean,Mathlib/Geometry/Manifold/Algebra/Monoid.lean,Mathlib/GroupTheory/Congruence/BigOperators.lean,Mathlib/LinearAlgebra/ConvexSpace/AffineSpace.lean,Mathlib/LinearAlgebra/DFinsupp.lean,Mathlib/LinearAlgebra/Dimension/LinearMap.lean,Mathlib/LinearAlgebra/Finsupp/Pi.lean,Mathlib/LinearAlgebra/Lagrange.lean,Mathlib/LinearAlgebra/Matrix/Charpoly/Coeff.lean,Mathlib/LinearAlgebra/Matrix/Ideal.lean,Mathlib/LinearAlgebra/Matrix/Polynomial.lean,Mathlib/LinearAlgebra/TensorProduct/Vanishing.lean,Mathlib/MeasureTheory/Function/ConditionalExpectation/Basic.lean,Mathlib/MeasureTheory/Function/ConditionalLExpectation.lean	218	31	['Vierkantor', 'YaelDillies', 'adomani', 'github-actions', 'mathlib-bors', 'mathlib-merge-conflicts', 'themathqueen']	nobody	6-71198 6 days ago	7-1753 7 days ago	6-51847 6 days
31513	FLDutchmann author:FLDutchmann	feat(Tactic): `polynomial` tactic	Implement tactic for proving equality of polynomials. This tactic is part of a larger suite (see https://github.com/leanprover-community/mathlib4/pull/30374). - [ ] depends on: #31508 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-meta	1824/6	Mathlib.lean,Mathlib/Tactic.lean,Mathlib/Tactic/Algebra/Basic.lean,Mathlib/Tactic/Algebra/Lemmas.lean,Mathlib/Tactic/Polynomial/Basic.lean,Mathlib/Tactic/Polynomial/Core.lean,Mathlib/Util/Qq.lean,MathlibTest/Algebra.lean,MathlibTest/Polynomial.lean,scripts/noshake.json	10	3	['github-actions', 'mathlib-dependent-issues', 'mathlib4-merge-conflict-bot']	Vierkantor assignee:Vierkantor	5-75598 5 days ago	161-80792 161 days ago	0-462 7 minutes
33662	Pjotr5 author:Pjotr5	feat(Algebra/Order/BigOperators/Expect): add lemmas and strict variants	### Summary - Combine `le_expect_nonempty_of_subadditive` and `le_expect_of_subadditive` into a single lemma `le_expect_of_subadditive`. The extra assumptions `(hs : s.Nonempty)` and `(h_zero : m 0 = 0)` are unnecessary (since `m 0 = 0` follows from `h_div`). This requires a small downstream update to `Mathlib/Analysis/RCLike/Basic.lean` (`norm_expect_le`). - Add strict-inequality variants: `expect_lt_expect`, `expect_lt`, `lt_expect`. - Add existence lemmas: `exists_le_of_expect_le_expect`, `exists_le_of_le_expect`, `exists_le_of_expect_le`, and `exists_lt_of_expect_lt_expect`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra merge-conflict label:t-algebra$	46/16	Mathlib/Algebra/Order/BigOperators/Expect.lean,Mathlib/Analysis/RCLike/Basic.lean	2	9	['Pjotr5', 'b-mehta', 'felixpernegger', 'github-actions', 'mathlib-merge-conflicts']	eric-wieser assignee:eric-wieser	5-63163 5 days ago	7-58855 7 days ago	98-39933 98 days
37530	mcdoll author:mcdoll	fix(Topology/Algebra): fix bad simps and make arguments implicit for `PointwiseConvergenceCLM`	We delete all `simps` calls in the definitions of operators on `PointwiseConvergenceCLM` and replace them with `apply_apply` lemmas that do not abuse the defeq between `SLₚₜ` and `SL`. This made the linter discover some typeclass duplications, which we remove by restructuring the file. As a consequence of the new `simp` lemmas, we can remove all `set_option backward.isDefEq.respectTransparency false in` in `Analysis.Distribution.TemperedDistribution`. Moreover, we make several arguments implicit, which can be inferred in almost all practical situations. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	not-ready-to-merge merge-conflict	88/69	Mathlib/Analysis/Distribution/TemperedDistribution.lean,Mathlib/Topology/Algebra/Module/Spaces/PointwiseConvergenceCLM.lean	2	5	['github-actions', 'jcommelin', 'mathlib-merge-conflicts', 'mcdoll']	nobody	3-30698 3 days ago	3-30699 3 days ago	14-57413 14 days
37593	IlPreteRosso author:IlPreteRosso	refactor(Data.Finset.Antidiagonal): rename set-based defs to `setAntidiagonal`	Renames set-based `Finset.mulAntidiagonal` → `setMulAntidiagonal` (and SMul/VAdd variants) to free the `mulAntidiagonal` name for the planned `HasMulAntidiagonal` typeclass. Deprecation aliases added. Supersedes #34551	t-ring-theory new-contributor merge-conflict	178/96	Mathlib/Algebra/Order/Antidiag/Prod.lean,Mathlib/Data/Finset/MulAntidiagonal.lean,Mathlib/Data/Finset/SMulAntidiagonal.lean,Mathlib/RingTheory/HahnSeries/Multiplication.lean,Mathlib/RingTheory/HahnSeries/PowerSeries.lean,Mathlib/RingTheory/HahnSeries/Summable.lean	6	3	['github-actions', 'mathlib-merge-conflicts']	nobody	3-30697 3 days ago	3-30698 3 days ago	15-58995 15 days
37444	vihdzp author:vihdzp	feat: typeclass for zero-dimensional spaces	--- - [ ] depends on: #37317 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology large-import merge-conflict	151/110	Mathlib/Topology/Algebra/ClopenNhdofOne.lean,Mathlib/Topology/Category/LightProfinite/Basic.lean,Mathlib/Topology/Category/Profinite/Basic.lean,Mathlib/Topology/Category/Profinite/CofilteredLimit.lean,Mathlib/Topology/Category/Stonean/Basic.lean,Mathlib/Topology/ClopenBox.lean,Mathlib/Topology/Order.lean,Mathlib/Topology/Order/WithTop.lean,Mathlib/Topology/Separation/CompletelyRegular.lean,Mathlib/Topology/Separation/DisjointCover.lean,Mathlib/Topology/Separation/Lemmas.lean,Mathlib/Topology/Separation/Profinite.lean,Mathlib/Topology/UniformSpace/Ultra/Basic.lean	13	17	['ADedecker', 'FernandoChu', 'github-actions', 'mathlib-dependent-issues', 'mathlib-merge-conflicts', 'vihdzp']	nobody	1-9981 1 day ago	1-11053 1 day ago	0-5190 1 hour
37939	AntoineChambert-Loir author:AntoineChambert-Loir	feat(Order/Completion): embed a linear order into a dense and complete linear order	The aim of the PR is to prove the following theorem that will be used as an input to [Sion.DMCompletion.exists_isSaddlePointOn](https://leanprover-community.github.io/mathlib4_docs/Mathlib/Topology/Sion.html#Sion.DMCompletion.exists_isSaddlePointOn) : If `β` is any linear order, then there exists a complete and dense linear order `γ` together with a continuous embedding `ι : β ↪o γ` (for the order topologies on `β` and `γ`). Meanwhile, the PR also records various instances about dense orders and lemmas regarding the Dedekind MacNeille completion and lexicographic orders. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-order merge-conflict	208/3	Mathlib.lean,Mathlib/Data/Prod/Lex.lean,Mathlib/Order/Completion.lean,Mathlib/Topology/Order/Completion.lean,Mathlib/Topology/Sion.lean	5	50	['ADedecker', 'AntoineChambert-Loir', 'github-actions', 'mathlib-merge-conflicts', 'vihdzp']	vihdzp assignee:vihdzp	0-60286 16 hours ago	0-60287 16 hours ago	2-83793 2 days
38239	vihdzp author:vihdzp	chore(Order/SuccPred/Limit): reorganize sections	In an effort to keep the file better organized, we move theorems which use `SuccOrder`/`PredOrder` as an assumption to a new section. No theorems have been changed. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-order merge-conflict	95/110	Mathlib/Order/SuccPred/Limit.lean	1	2	['github-actions', 'mathlib-merge-conflicts']	nobody	0-60275 16 hours ago	0-60276 16 hours ago	2-43850 2 days
38054	chrisflav author:chrisflav	feat(RingTheory): category of finite étale algebras over a separably closed field	We define the category of finite étale `R`-algebras for a ring `R` and show it is equivalent to `FintypeCat` if `R` is a separably closed field. From Pi1. --- - [ ] depends on: #38016 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-ring-theory large-import merge-conflict	337/2	Mathlib.lean,Mathlib/Algebra/Algebra/Pi.lean,Mathlib/FieldTheory/IntermediateField/Adjoin/Basic.lean,Mathlib/FieldTheory/IsSepClosed.lean,Mathlib/RingTheory/Artinian/Module.lean,Mathlib/RingTheory/Etale/Basic.lean,Mathlib/RingTheory/Etale/Field.lean,Mathlib/RingTheory/Etale/Finite.lean,Mathlib/RingTheory/TensorProduct/Maps.lean,Mathlib/RingTheory/TotallySplit.lean	10	4	['github-actions', 'mathlib-dependent-issues', 'mathlib-merge-conflicts']	nobody	0-14454 4 hours ago	0-14454 3 hours ago	0-69939 19 hours

Stale new contributor PRs

Number	Author	Title	Description	Labels	+/-	Modified files (first 100)	📝	💬	All users who commented or reviewed	Assignee(s)	Updated	Last status change	total time in review
14563	awueth author:awueth	feat: if-then-else of exclusive or statement	--- If `¬(P ∧ Q)` then `ite (P ∨ Q) a 1 = (ite P a 1) * (ite Q a 1)` [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-author t-algebra new-contributor label:t-algebra$	5/0	Mathlib/Algebra/Group/Basic.lean	1	3	['eric-wieser', 'github-actions', 'kim-em']	nobody	615-17784 1 year ago	unknown	unknown
12751	Command-Master author:Command-Master	feat: add lemmas for Nat/Bits, Nat/Bitwise and Nat/Size	Remove `@[simp]` from `Nat.bit_false` and `Nat.bit_true`, as `bit0` and `bit1` are deprecated, and add some lemmas to `Bits`, `Bitwise` and `Size`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-data new-contributor	66/7	Mathlib/Data/Nat/Bits.lean,Mathlib/Data/Nat/Bitwise.lean,Mathlib/Data/Nat/Multiplicity.lean,Mathlib/Data/Nat/Size.lean	4	26	['Command-Master', 'Rida-Hamadani', 'Ruben-VandeVelde', 'YaelDillies', 'github-actions', 'jcommelin']	nobody	611-2693 1 year ago	unknown	unknown
15121	Eloitor author:Eloitor	feat: iff theorems for IsSplitEpi and IsSplitMono in opposite category	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-author t-category-theory new-contributor	40/0	Mathlib/CategoryTheory/EpiMono.lean	1	3	['github-actions', 'joelriou', 'mattrobball']	nobody	597-63928 1 year ago	unknown	unknown
14242	js2357 author:js2357	feat: Prove equivalence of `isDedekindDomain` and `isDedekindDomainDvr`	Prove that `isDedekindDomainDvr` is equivalent to both `isDedekindDomain` and `isDedekindDomainInv`. Specifically, prove `isDedekindDomainDvr A → isDedekindDomainInv A`, because `isDedekindDomain A → isDedekindDomainDvr A` and `IsDedekindDomain A ↔ IsDedekindDomainInv A` are already in Mathlib. - [x] depends on: #14099 - [x] depends on: #14216 - [ ] depends on: #14237 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-algebra blocked-by-other-PR new-contributor label:t-algebra$	269/1	Mathlib.lean,Mathlib/RingTheory/DedekindDomain/Dvr.lean,Mathlib/RingTheory/FractionalIdeal/LocalizedAtPrime.lean,Mathlib/RingTheory/Localization/Basic.lean	4	2	['github-actions', 'leanprover-community-mathlib4-bot']	nobody	574-74987 1 year ago	unknown	unknown
16887	metinersin author:metinersin	feat(ModelTheory/Complexity): define conjunctive and disjunctive formulas	Defines `FirstOrder.Language.BoundedFormula.IsConjunctive` and `FirstOrder.Language.BoundedFormula.IsDisjunctive`. --- - [ ] depends on: #16885 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict blocked-by-other-PR new-contributor t-logic	300/7	Mathlib/ModelTheory/Complexity.lean,Mathlib/ModelTheory/Equivalence.lean,Mathlib/ModelTheory/Syntax.lean	3	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	566-70965 1 year ago	unknown	unknown
16888	metinersin author:metinersin	feat(ModelTheory/Complexity): Define conjunctive and disjunctive normal forms	Define `FirstOrder.Language.BoundedFormula.IsDNF` and `FirstOrder.Language.BoundedFormula.IsCNF`. --- - [ ] depends on: #16887 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict blocked-by-other-PR new-contributor t-logic	415/7	Mathlib/ModelTheory/Complexity.lean,Mathlib/ModelTheory/Equivalence.lean,Mathlib/ModelTheory/Syntax.lean	3	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	566-70965 1 year ago	unknown	unknown
16889	metinersin author:metinersin	feat(ModelTheory/Complexity): Normal forms	Defines `FirstOrder.Language.BoundedFormula.toDNF` and `FirstOrder.Language.BoundedFormula.toCNF` - given a quantifier-free formula, these construct a semantically equivalent formula in disjunctive normal form and conjunctive normal form, respectively. --- - [ ] depends on: #16888 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict blocked-by-other-PR new-contributor t-logic	525/7	Mathlib/ModelTheory/Complexity.lean,Mathlib/ModelTheory/Equivalence.lean,Mathlib/ModelTheory/Syntax.lean	3	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	566-70964 1 year ago	unknown	unknown
14619	Command-Master author:Command-Master	chore: Merge `Trunc` to `Squash`	Remove `Trunc` and use `Squash` instead --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict WIP new-contributor	197/211	Mathlib/CategoryTheory/EpiMono.lean,Mathlib/CategoryTheory/Preadditive/Biproducts.lean,Mathlib/Data/DFinsupp/Basic.lean,Mathlib/Data/Fintype/Basic.lean,Mathlib/Data/Fintype/Card.lean,Mathlib/Data/Fintype/Option.lean,Mathlib/Data/Fintype/Perm.lean,Mathlib/Data/Fintype/Quotient.lean,Mathlib/Data/Quot.lean,Mathlib/Data/Semiquot.lean,Mathlib/GroupTheory/Perm/Cycle/Factors.lean,Mathlib/GroupTheory/Perm/Sign.lean,Mathlib/Logic/Equiv/List.lean	13	3	['Command-Master', 'github-actions', 'vihdzp']	nobody	557-31115 1 year ago	unknown	unknown
12750	Command-Master author:Command-Master	feat: define Gray code	--- Define binary reflected gray code, both as a permutation of `Nat` and as a permutation of `BitVec n`, and prove some theorems about them. Additionally, remove `@[simp]` from `Nat.bit_false` and `Nat.bit_true`, as `bit0` and `bit1` are deprecated, and add some lemmas to `Bits`, `Bitwise` and `Size`. - [ ] depends on: #12751 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	blocked-by-other-PR t-data new-contributor merge-conflict awaiting-author	226/0	Mathlib.lean,Mathlib/Data/Nat/Bits.lean,Mathlib/Data/Nat/Bitwise.lean,Mathlib/Data/Nat/GrayCode.lean,Mathlib/Data/Nat/Size.lean	5	5	['Rida-Hamadani', 'alreadydone', 'github-actions', 'grunweg', 'leanprover-community-mathlib4-bot']	nobody	549-7222 1 year ago	unknown	unknown
14598	Command-Master author:Command-Master	chore: add typeclasses to unify various `add_top`, `add_eq_top`, etc.	Add the four typeclasses `IsTopAbsorbing`, `IsBotAbsorbing`, `NoTopSum`, `NoBotSum`, as additive equivalents for `MulZeroClass` and `NoZeroDivisors`. Add instances of these for `ENNReal`, `WithTop α`, `WithBot α`, `PUnit`, `EReal`, `PartENat`, `Measure`, `Interval` and `Filter`. Also split `Algebra/Order/AddGroupWithTop` to `Algebra/Order/Group/WithTop` and `Algebra/Order/Monoid/WithTop` --- Previous usages of lemmas with quantified names like `WithTop.add_top` have to be changed to just `add_top`. `add_lt_top` is `@[simp]`, in accordance with `ENNReal.add_lt_top` being `@[simp]`. This affects `WithTop.add_lt_top` which previously hadn't been `@[simp]`. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-algebra t-order new-contributor label:t-algebra$	264/195	Archive/Wiedijk100Theorems/BallotProblem.lean,Mathlib.lean,Mathlib/Algebra/Order/Group/WithTop.lean,Mathlib/Algebra/Order/GroupWithZero/Canonical.lean,Mathlib/Algebra/Order/Interval/Basic.lean,Mathlib/Algebra/Order/Monoid/Unbundled/Basic.lean,Mathlib/Algebra/Order/Monoid/Unbundled/Defs.lean,Mathlib/Algebra/Order/Monoid/Unbundled/WithTop.lean,Mathlib/Algebra/Order/Monoid/WithTop.lean,Mathlib/Algebra/PUnitInstances/Order.lean,Mathlib/Algebra/Polynomial/Degree/Definitions.lean,Mathlib/Algebra/Polynomial/Monic.lean,Mathlib/Algebra/Tropical/Basic.lean,Mathlib/Analysis/Analytic/Meromorphic.lean,Mathlib/Analysis/Normed/Lp/ProdLp.lean,Mathlib/Analysis/NormedSpace/ENorm.lean,Mathlib/Analysis/SpecialFunctions/JapaneseBracket.lean,Mathlib/Analysis/SpecialFunctions/Log/ENNRealLog.lean,Mathlib/Data/ENNReal/Operations.lean,Mathlib/Data/ENat/Basic.lean,Mathlib/Data/Nat/PartENat.lean,Mathlib/Data/Nat/WithBot.lean,Mathlib/Data/Real/EReal.lean,Mathlib/LinearAlgebra/Lagrange.lean,Mathlib/MeasureTheory/Covering/Differentiation.lean,Mathlib/MeasureTheory/Decomposition/Lebesgue.lean,Mathlib/MeasureTheory/Function/ConditionalExpectation/CondexpL1.lean,Mathlib/MeasureTheory/Function/Jacobian.lean,Mathlib/MeasureTheory/Function/L1Space.lean,Mathlib/MeasureTheory/Function/L2Space.lean,Mathlib/MeasureTheory/Function/LpSeminorm/Basic.lean,Mathlib/MeasureTheory/Function/LpSeminorm/TriangleInequality.lean,Mathlib/MeasureTheory/Function/LpSpace.lean,Mathlib/MeasureTheory/Function/StronglyMeasurable/Basic.lean,Mathlib/MeasureTheory/Function/UniformIntegrable.lean,Mathlib/MeasureTheory/Integral/Bochner.lean,Mathlib/MeasureTheory/Integral/MeanInequalities.lean,Mathlib/MeasureTheory/Integral/SetIntegral.lean,Mathlib/MeasureTheory/Integral/VitaliCaratheodory.lean,Mathlib/MeasureTheory/Measure/Hausdorff.lean,Mathlib/MeasureTheory/Measure/Lebesgue/Basic.lean,Mathlib/MeasureTheory/Measure/LevyProkhorovMetric.lean,Mathlib/MeasureTheory/Measure/MeasureSpace.lean,Mathlib/MeasureTheory/Measure/MeasureSpaceDef.lean,Mathlib/MeasureTheory/Measure/Regular.lean,Mathlib/MeasureTheory/Measure/Typeclasses.lean,Mathlib/NumberTheory/Padics/PadicNumbers.lean,Mathlib/Order/Filter/Pointwise.lean,Mathlib/Probability/Kernel/Defs.lean,Mathlib/Probability/Martingale/Convergence.lean,Mathlib/RingTheory/Multiplicity.lean,Mathlib/RingTheory/MvPowerSeries/NoZeroDivisors.lean,Mathlib/RingTheory/UniqueFactorizationDomain.lean,Mathlib/Topology/EMetricSpace/Defs.lean,Mathlib/Topology/MetricSpace/Bounded.lean,Mathlib/Topology/MetricSpace/HausdorffDistance.lean,Mathlib/Topology/MetricSpace/Lipschitz.lean	57	30	['Command-Master', 'YaelDillies', 'github-actions']	nobody	532-35498 1 year ago	unknown	unknown
16885	metinersin author:metinersin	feat(ModelTheory/Complexity): define literals	Defines `FirstOrder.Language.BoundedFormula.IsLiteral` and `FirstOrder.Language.BoundedFormula.simpleNot` - an auxiliary operation that takes the negation of a formula and does some simplification. --- - [x] depends on: #16800 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict awaiting-author new-contributor t-logic	148/5	Mathlib/ModelTheory/Complexity.lean,Mathlib/ModelTheory/Equivalence.lean,Mathlib/ModelTheory/Semantics.lean,Mathlib/ModelTheory/Syntax.lean	4	20	['YaelDillies', 'awainverse', 'github-actions', 'mathlib4-dependent-issues-bot', 'metinersin']	nobody	529-78019 1 year ago	unknown	unknown
13248	hcWang942 author:hcWang942	feat: basic concepts of auction theory	## Description Formalise some core concepts and results in auction theory: this includes definitions for first-price and second-price auctions, as well as several fundamental results and helping lemmas. This is the very first PR of the project formalizing core concepts and results in auction theory. Our group is working on more contributions on the formalization of game theory prefix. Co-authored-by: Ma Jiajun ## Reference Roughgarden, Tim. *Twenty Lectures on Algorithmic Game Theory*. Cambridge University Press, 2020. [Link](https://www.cambridge.org/core/books/twenty-lectures-on-algorithmic-game-theory/A9D9427C8F43E7DAEF8C702755B6D72B) --- - [x] Will depend on #14163 once that PR is merged. The Fintype lemmas introduced by this PR have been added in that PR and will be removed from here once that PR gets merged ## Current plan for formalization of Game Theory The current plan for the formalizing of Game Theory include: #### 1. Auction Theory. 🎉 _(200+ lines, this PR)_ - Essential definitions of Sealed-bid auction, First-price auction and Second-price auction. - First-price auction has no dominant strategy. - Second-price auction has dominant strategy. (Second-price auction is DSIC) #### 2. Mechanism design & Myerson's Lemma. 🎉 (400+ lines, pending for modification to Mathlib Standard) - Mechanism design An allocation rule is implementable if there exists - Dominant Strategy Incentive Compatible (DSIC) payment rule - An allocation rule is monotone if for every bidder’s gain is nondecreasing w.r.t. her/his bid - Myerson's Lemma Implementable ⇔ Monotone In the above case, the DSIC payment rule is unique. #### 3. von Neumann‘s Minimax Theorem. 🎉 (800+ lines, pending for modification to Mathlib Standard) - Equilibrium in zero sum game - Formalization strategy: via Loomis’s theorem. #### 4. Nash Equilibrium. 🎉 (pending for modification to Mathlib Standard) #### 5. Brouwer fixed-point theorem. (Work in Progress) #### 6. More Mechanism design. (Planning)	merge-conflict awaiting-author new-contributor t-logic	204/0	Mathlib.lean,Mathlib/GameTheory/Auction/Basic.lean,docs/references.bib	3	148	['Shreyas4991', 'YaelDillies', 'eric-wieser', 'faenuccio', 'github-actions', 'grunweg', 'hcWang942', 'tb65536', 'urkud', 'vihdzp']	hcWang942 assignee:hcWang942	525-30451 1 year ago	unknown	unknown
19125	yhtq author:yhtq	feat: add theorems to transfer `IsGalois` between pairs of fraction rings	feat: add theorems to transfer `IsGalois` between pairs of fraction rings. - [x] depends on: #18404 - [x] depends on: #19124 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-algebra new-contributor label:t-algebra$	121/0	Mathlib.lean,Mathlib/FieldTheory/Galois/IsFractionRing.lean,Mathlib/RingTheory/Localization/FractionRing.lean	3	3	['github-actions', 'mathlib4-dependent-issues-bot', 'tb65536']	nobody	495-52868 1 year ago	unknown	unknown
17739	Aaron1011 author:Aaron1011	feat(Topology/Order/DenselyOrdered): prove Not (IsOpen) for intervals	Prove that Iic/Ici/Ioc/Ico/Icc intervals are not open in densely ordered topologies with no min/max element --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict awaiting-author t-topology new-contributor	27/0	Mathlib/Topology/Order/DenselyOrdered.lean	1	8	['github-actions', 'vihdzp']	nobody	461-74880 1 year ago	unknown	unknown
15711	znssong author:znssong	feat(Combinatorics/SimpleGraph): Some lemmas about walk, cycle and Hamiltonian cycle	--- These lemmas are separated from the `meow-sister/BondyChvatal` branch and will be needed for the proof of the Bondy-Chvátal theorem. - [x] depends on: #15536 - [x] depends on: #16294	merge-conflict awaiting-author t-combinatorics new-contributor	407/3	Mathlib/Combinatorics/SimpleGraph/Finite.lean,Mathlib/Combinatorics/SimpleGraph/Hamiltonian.lean,Mathlib/Combinatorics/SimpleGraph/Path.lean,Mathlib/Combinatorics/SimpleGraph/Walk.lean	4	22	['Rida-Hamadani', 'YaelDillies', 'github-actions', 'mathlib4-dependent-issues-bot', 'znssong']	nobody	461-7566 1 year ago	unknown	unknown
18629	tomaz1502 author:tomaz1502	feat(Computability.Timed): Formalization of runtime complexity of List.merge	This PR adds the formalization of the runtime complexity of the merge function, defined in `Data/List/Sort`. Requires: https://github.com/leanprover-community/mathlib4/pull/15450 References: - Previous PR on mathlib3: https://github.com/leanprover-community/mathlib3/pull/14494/ - First discussion on Zulip: https://leanprover.zulipchat.com/#narrow/stream/113488-general/topic/BSc.20Final.20Project/near/220647062 - Second disussion on Zulip: https://leanprover.zulipchat.com/#narrow/stream/113488-general/topic/Formalization.20of.20Runtime.20Complexity.20of.20Sorting.20Algorithms/near/284184450 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-computability awaiting-author new-contributor	186/0	Mathlib.lean,Mathlib/Computability/Timed/InsertionSort.lean,Mathlib/Computability/Timed/Merge.lean	3	2	['github-actions', 'trivial1711']	nobody	460-59885 1 year ago	unknown	unknown
18461	hannahfechtner author:hannahfechtner	feat: left and right common multiples mixins	add mixins for left and right common multiples. These carry the data of what factors are used to create the common multiples --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-author t-algebra new-contributor label:t-algebra$	78/0	Mathlib/Algebra/Group/Defs.lean	1	13	['github-actions', 'hannahfechtner', 'jcommelin', 'kbuzzard', 'kim-em', 'trivial1711']	nobody	457-21065 1 year ago	unknown	unknown
19291	PieterCuijpers author:PieterCuijpers	feat(Algebra/Order/Hom): add quantale homomorphism	Definition of quantale homomorphisms as functions that are both semigroup homomorphisms and complete lattice homomorphisms. --- - [x] depends on: #19810 - [x] depends on: #19811 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict awaiting-author t-algebra new-contributor label:t-algebra$	209/0	Mathlib.lean,Mathlib/Algebra/Order/Hom/Quantale.lean,scripts/noshake.json	3	29	['PieterCuijpers', 'YaelDillies', 'github-actions', 'kim-em', 'mathlib4-dependent-issues-bot']	nobody	455-81544 1 year ago	unknown	unknown
20372	jvlmdr author:jvlmdr	feat(MeasureTheory/Function): Add ContinuousLinearMap.bilinearCompLp(L)	Introduce ContinuousLinearMap.bilinearCompLp and bilinearCompLpL. Generalize eLpNorm_le_eLpNorm_mul_eLpNorm theorems to include constant C in bound condition. --- Expect this may be useful for defining tempered distributions from functions in `L^p`. The definitions more or less follow `ContinuousLinearMap.compLp...`. Names are loosely analogous to `ContinuousLinearMap.bilinearComp` and `SchwartzMap.bilinLeftCLM`. Note: I preferred the spelling `hpqr : p⁻¹ + q⁻¹ = r⁻¹` with `f` in `L^p` and `g` in `L^q` to `hpqr : 1 / p = 1 / q + 1 / r`. It's easier to obtain from `ENNReal.IsConjExponent` too. A few questions: - [ ] I defined `bilinear{Left,Right}LpL` in addition to `bilinearCompLpL` because `LinearMap.mkContinuous₂` is marked as `noncomputable` and `LinearMap.mkContinuous` is not. Is this worth the extra definitions? (Note: This is not visible in the source due to `noncomputable section`.) - [ ] Should I use `C : ℝ` instead of `C : NNReal` for `eLpNorm_le_eLpNorm_mul_eLpNorm'_of_norm'`? - [ ] Is it going to be painful to have `[Fact (1 ≤ p)] [Fact (1 ≤ q)] [Fact (1 ≤ r)]`? I don't think there's a way to avoid it though. Maybe providing specialized versions for `p.IsConjExponent q` with `L^1`? Naming: - [ ] Is it satisfactory to add a `'` to the `eLpNorm_le_eLpNorm_mul_eLpNorm ` definitions in `CompareExp.lean` where `≤ ‖f x‖ * ‖g x‖` has been replaced with `≤ C * ‖f x‖ * ‖g x‖`? These could replace the existing theorems, although I don't want to break backwards compatibility. There are 5 instances: `eLpNorm_le_eLpNorm_top_mul_eLpNorm'`, `eLpNorm_le_eLpNorm_mul_eLpNorm_top'`, `eLpNorm'_le_eLpNorm'_mul_eLpNorm''`, `eLpNorm_le_eLpNorm_mul_eLpNorm_of_nnnorm'`, `eLpNorm_le_eLpNorm_mul_eLpNorm'_of_norm'` (I'm not sure why the existing theorem `eLpNorm_le_eLpNorm_mul_eLpNorm'_of_norm` has an internal `'`) - [ ] Is `bilinearLeftLpL` a suitable name? Other options: `bilinearCompLpLeftL`, `bilinearCompLeftLpL`, `bilinLeftLpL` (analogous to `SchwartzMap.bilinLeftCLM`) [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-measure-probability new-contributor	203/40	Mathlib/MeasureTheory/Function/LpSeminorm/CompareExp.lean,Mathlib/MeasureTheory/Function/LpSpace.lean	2	1	['github-actions']	nobody	449-12492 1 year ago	unknown	unknown
20248	peabrainiac author:peabrainiac	feat(Topology/Compactness): first-countable locally path-connected spaces are delta-generated	Shows that all first-countable locally path-connected spaces are delta-generated (so in particular all normed spaces and convex subsets thereof are), and that delta-generated spaces are equivalently generated by the unit interval or standard simplices. --- - [ ] depends on: #21616 In principle, this should be close to all that's required to show that all simplicial complexes and CW-complexes are delta-generated; I just haven't done it yet because I'm not sure which file to best do it in. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	blocked-by-other-PR large-import new-contributor merge-conflict awaiting-author t-topology	1189/813	Mathlib.lean,Mathlib/Geometry/Manifold/ChartedSpace.lean,Mathlib/Topology/Algebra/Module/LocallyConvex.lean,Mathlib/Topology/Compactness/DeltaGeneratedSpace.lean,Mathlib/Topology/Connected/LocPathConnected.lean,Mathlib/Topology/Connected/PathConnected.lean,Mathlib/Topology/ContinuousOn.lean,Mathlib/Topology/Homotopy/HSpaces.lean,Mathlib/Topology/Path.lean	9	22	['YaelDillies', 'github-actions', 'kbuzzard', 'mathlib4-dependent-issues-bot', 'peabrainiac']	nobody	436-56202 1 year ago	unknown	unknown
19943	AlexLoitzl author:AlexLoitzl	feat(Computability): Add Chomsky Normal Form Grammar and translation	- Define Chomsky normal form grammars - Add language-preserving translation between context-free grammars and Chomsky normal form grammars Co-authored-by: Martin Dvorak martin.dvorak@matfyz.cz --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-computability awaiting-author new-contributor	3151/0	Mathlib.lean,Mathlib/Computability/ChomskyNormalForm/Basic.lean,Mathlib/Computability/ChomskyNormalForm/EmptyElimination.lean,Mathlib/Computability/ChomskyNormalForm/LengthRestriction.lean,Mathlib/Computability/ChomskyNormalForm/TerminalRestriction.lean,Mathlib/Computability/ChomskyNormalForm/Translation.lean,Mathlib/Computability/ChomskyNormalForm/UnitElimination.lean,Mathlib/Computability/ContextFreeGrammar.lean	8	59	['AlexLoitzl', 'YaelDillies', 'github-actions', 'kim-em', 'madvorak']	nobody	432-3901 1 year ago	unknown	unknown
21501	sksgurdldi author:sksgurdldi	feat(List): add sum_zipWith_eq_finset_sum	### Description: This PR adds the lemma `List.sum_zipWith_eq_finset_sum` to `Mathlib.Algebra.BigOperators.Group.Finset.Basic`. #### Statement: The sum of the `zipWith` operation on two lists equals the sum of applying the operation to corresponding elements of the two lists, indexed over the minimum of their lengths. #### Formal Statement: ```lean lemma sum_zipWith_eq_finset_sum [Inhabited α] [Inhabited β] [AddCommMonoid γ] {op : α → β → γ} (l : List α) (m : List β) : (List.zipWith op l m).sum = ∑ x ∈ (Finset.range (Nat.min l.length m.length)), op (l[x]!) (m[x]!) ``` #### Remarks: - This lemma provides a useful equivalence between `List.zipWith` and summation over a `Finset.range` indexed by `Nat.min l.length m.length`. - It can be helpful in algebraic manipulations involving list-based summations. #### Dependencies: No additional dependencies. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-author t-algebra new-contributor label:t-algebra$	43/0	Mathlib/Algebra/BigOperators/Group/Finset/Basic.lean	1	1	['github-actions', 'j-loreaux']	nobody	426-59072 1 year ago	unknown	unknown
21959	BGuillemet author:BGuillemet	feat(Topology/ContinuousMap): Stone-Weierstrass theorem for MvPolynomial	Add the subalgebra of multivariate polynomials and prove it separates points, on the same model as `ContinuousMap/Polynomial.lean`. Prove the Stone-Weierstrass theorem and some variations for multivariate polynomials. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-topology new-contributor	285/1	Mathlib.lean,Mathlib/Topology/ContinuousMap/MvPolynomial.lean,Mathlib/Topology/ContinuousMap/StoneWeierstrass.lean	3	1	['github-actions']	nobody	412-84913 1 year ago	unknown	unknown
15578	znssong author:znssong	feat(Function): Fixed points of function `f` with `f(x) >= x`	We added some lemmas of fixed points of function `f` with `f(x) >= x`, where `f : α → α` is a function on a finite type `α`. This will be needed in proof of Bondy-Chvátal theorem. --- See also branch `meow-sister/BondyChvatal`. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict awaiting-author t-analysis new-contributor	82/0	Mathlib.lean,Mathlib/Dynamics/FixedPoints/Basic.lean,Mathlib/Dynamics/FixedPoints/Increasing.lean	3	32	['Ruben-VandeVelde', 'YaelDillies', 'github-actions', 'urkud', 'vihdzp', 'znssong']	nobody	404-80739 1 year ago	unknown	unknown
21018	markimunro author:markimunro	feat(Data/Matrix): add file with key definitions and theorems about elementary row operations	Prove that each elementary row operation is equivalent to a multiplication by an elementary matrix, has another row operation which inverts it, and that each elementary matrix has a left inverse. This is a very large PR and I understand it will take time. This is my first one and will likely have issues but I will be ready to answer questions/fix them as soon as possible. Co-authored-by: Christopher Lynch --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data enhancement new-contributor merge-conflict awaiting-author	1230/0	Mathlib.lean,Mathlib/Data/Matrix/ElementaryRowOperations.lean,Mathlib/Data/Matrix/GaussianElimination.lean,Mathlib/Data/Matrix/GaussianEliminationOld,Mathlib/Data/Matrix/oldnames,et --hard 18533caba32,lean-toolchain	7	17	['chrisflav', 'eric-wieser', 'github-actions', 'j-loreaux', 'markimunro']	nobody	386-29738 1 year ago	unknown	unknown
15212	victorliu5296 author:victorliu5296	feat: Add fundamental theorem of calculus-2 for Banach spaces	add the Mean Value Theorem for Banach spaces to the library and include reference for the theorem statement This theorem states that if `f : X → Y` is differentiable along the line segment from `a` to `b`, then the change in `f` equals the integral of its derivative along this path. This extends the mean value theorem to Banach spaces. This can be used for the eventual proof of the Newton-Kantorovich theorem with 1 constant contained inside the added reference. Here is the discussion on Zulipchat: https://leanprover.zulipchat.com/#narrow/stream/287929-mathlib4/topic/Contributing.20FTC-2.20for.20Banach.20spaces	t-measure-probability new-contributor merge-conflict awaiting-author t-analysis	60/1	Mathlib/MeasureTheory/Integral/FundThmCalculus.lean	1	3	['github-actions', 'hrmacbeth', 'victorliu5296']	nobody	381-24727 1 year ago	unknown	unknown
22308	plp127 author:plp127	feat (Analysis/Convex): Generalize `Convex` lemmas to `StarConvex`	This PR generalizes many lemmas assuming `Convex 𝕜 s` to assume `StarConvex 𝕜 0 s`. --- - [x] depends on: #22421 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict WIP t-analysis new-contributor	30/18	Mathlib/Analysis/Convex/Gauge.lean,Mathlib/Analysis/Convex/GaugeRescale.lean,Mathlib/Analysis/Convex/Star.lean,Mathlib/Analysis/LocallyConvex/AbsConvexOpen.lean	4	5	['Paul-Lez', 'github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	378-10647 1 year ago	unknown	unknown
21488	imbrem author:imbrem	feat(CategoryTheory/Monoidal): premonoidal categories	Add support for premonoidal categories --- Still want to add support for: - Premonoidal braided/symmetric categories - The monoidal coherence theorem, which I've already ported in my `discretion` library - The `coherence` tactic, which should work fine for premonoidal categories too but wanted to get this in front of reviewers ASAP to make sure my general approach was alright [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-category-theory new-contributor	900/361	Mathlib/Algebra/Category/ModuleCat/Presheaf/Monoidal.lean,Mathlib/CategoryTheory/Bicategory/End.lean,Mathlib/CategoryTheory/GradedObject/Monoidal.lean,Mathlib/CategoryTheory/Localization/Monoidal.lean,Mathlib/CategoryTheory/Monoidal/Braided/Basic.lean,Mathlib/CategoryTheory/Monoidal/Category.lean,Mathlib/CategoryTheory/Monoidal/Center.lean,Mathlib/CategoryTheory/Monoidal/CoherenceLemmas.lean,Mathlib/CategoryTheory/Monoidal/Discrete.lean,Mathlib/CategoryTheory/Monoidal/End.lean,Mathlib/CategoryTheory/Monoidal/Free/Basic.lean,Mathlib/CategoryTheory/Monoidal/Functor.lean,Mathlib/CategoryTheory/Monoidal/FunctorCategory.lean,Mathlib/CategoryTheory/Monoidal/Mon_.lean,Mathlib/CategoryTheory/Monoidal/Opposite.lean,Mathlib/CategoryTheory/Monoidal/Transport.lean,Mathlib/Tactic/CategoryTheory/Monoidal/Datatypes.lean,Mathlib/Tactic/CategoryTheory/Monoidal/Normalize.lean,Mathlib/Tactic/CategoryTheory/Monoidal/PureCoherence.lean,Mathlib/Tactic/CategoryTheory/MonoidalComp.lean,MathlibTest/StringDiagram.lean	21	9	['YaelDillies', 'github-actions', 'grunweg', 'imbrem', 'kim-em', 'leanprover-community-bot-assistant']	nobody	378-6915 1 year ago	unknown	unknown
20873	vbeffara author:vbeffara	feat(Topology/Covering): path lifting and homotopy lifting	This proves the existence and uniqueness of path and homotopy lifts through covering maps. --- I tried to separate as much of the proof as possible into separate PRs (which are already in Mathlib now), but the proof here relies on a monolithic construction of an explicit lift along a well-chosen subdivision, in `partial_lift`, with associated definitions. Only one standalone lean file added. An older WIP PR #10084 by Junyan Xu @alreadydone proves similar results using a very similar construction for path lifting, with a different argument to obtain continuity for homotopy lifting. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict awaiting-author t-topology new-contributor	281/1	Mathlib.lean,Mathlib/Topology/Covering/Basic.lean,Mathlib/Topology/Covering/Lift.lean	3	9	['alreadydone', 'github-actions', 'grunweg', 'vbeffara']	nobody	377-9643 1 year ago	unknown	unknown
20313	thefundamentaltheor3m author:thefundamentaltheor3m	feat(Data/Complex/Exponential): prove some useful results about the complex exponential.	This PR proves two basic results about the complex exponential: * `abs_exp_mul_I (x : ℂ) : abs (Complex.exp (I * x)) = Real.exp (-x.im)` * `one_sub_rexp_re_le_abs_one_sub_cexp (x : ℂ) : 1 - Real.exp x.re ≤ Complex.abs (1 - Complex.exp x)` Both results were proved as part of the sphere packing project. There's a chance they're too specific for mathlib, but I thought they were worth PRing anyway. Would it also be a good idea to tag `abs_exp_mul_I` with `simp`? Feedback/suggestions welcome. Note: `one_sub_rexp_re_le_abs_one_sub_cexp` was proved by Bhavik Mehta @b-mehta --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-analysis new-contributor	167/141	Mathlib.lean,Mathlib/Analysis/Complex/Basic.lean,Mathlib/Analysis/SpecialFunctions/Log/ERealExp.lean,Mathlib/Analysis/SpecialFunctions/Trigonometric/Chebyshev.lean,Mathlib/Data/Complex/Exponential/Defs.lean,Mathlib/Data/Complex/Exponential/Lemmas.lean,Mathlib/Data/Complex/ExponentialBounds.lean,Mathlib/Tactic/FunProp.lean,MathlibTest/Recall.lean,MathlibTest/positivity.lean	10	12	['b-mehta', 'github-actions', 'kim-em', 'thefundamentaltheor3m', 'trivial1711']	nobody	369-67241 1 year ago	unknown	unknown
20730	kuotsanhsu author:kuotsanhsu	feat(LinearAlgebra/Matrix/SchurTriangulation): prove Schur decomposition/triangulation	`Matrix.schur_triangulation` shows that a matrix over an algebraically closed field is unitarily similar to an upper triangular matrix --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict awaiting-author t-algebra new-contributor label:t-algebra$	317/2	Mathlib.lean,Mathlib/LinearAlgebra/Matrix/Block.lean,Mathlib/LinearAlgebra/Matrix/SchurTriangulation.lean,Mathlib/Logic/Equiv/Basic.lean	4	14	['eric-wieser', 'github-actions', 'kim-em', 'kuotsanhsu']	nobody	369-63373 1 year ago	unknown	unknown
22809	b-reinke author:b-reinke	feat: Category algebras and path algebras	This PR defines the category algebra of a linear category and path algebras of quivers. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	WIP t-algebra t-category-theory new-contributor label:t-algebra$	218/0	Mathlib/Algebra/Ring/Assoc.lean,Mathlib/CategoryTheory/Linear/CategoryAlgebra.lean,Mathlib/Combinatorics/Quiver/PathAlgebra.lean,Mathlib/Data/DFinsupp/BigOperators.lean	4	2	['b-reinke', 'github-actions']	nobody	354-27812 11 months ago	unknown	unknown
15654	TpmKranz author:TpmKranz	feat(Computability): language-preserving maps between NFA and RE	Map REs to NFAs via Thompson's construction and NFAs to REs using GNFAs Last chunk of #12648 --- - [ ] depends on: #15651 - [ ] depends on: #15649 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	blocked-by-other-PR new-contributor t-computability merge-conflict awaiting-zulip	985/2	Mathlib.lean,Mathlib/Computability/GNFA.lean,Mathlib/Computability/Language.lean,Mathlib/Computability/NFA.lean,Mathlib/Computability/RegularExpressions.lean,Mathlib/Data/FinEnum/Option.lean,docs/references.bib	7	3	['github-actions', 'leanprover-community-mathlib4-bot', 'meithecatte']	nobody	351-60491 11 months ago	unknown	unknown
24008	meithecatte author:meithecatte	chore(EpsilonNFA): replace manual lemmas with @[simps]	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-computability awaiting-author new-contributor	2/24	Mathlib/Computability/EpsilonNFA.lean	1	2	['YaelDillies', 'github-actions', 'urkud']	nobody	346-19670 11 months ago	unknown	unknown
23349	BGuillemet author:BGuillemet	feat: add LocallyLipschitzOn.lipschitzOnWith_of_isCompact and two small lemmas about Lipschitz functions	Main feat (in Mathlib/Topology/EMetricSpace/Basic.lean): if a function `f` from an extended pseudometric space to a pseudometric space is locally Lipschitz on a compact subset `s`, then `f` is Lipschitz on `s`. The theorem is true only when the codomain of `f` is a pseudometric space, so it needs imports from Mathlib/Topology/MetricSpace. Other small feat (in Mathlib/Analysis/Calculus/ContDiff/RCLike.lean): a function that is continuously differentiable on an open subset is locally Lipschitz on this subset. --- - [ ] depends on: #22890 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-topology large-import new-contributor	59/4	Mathlib/Analysis/Calculus/ContDiff/RCLike.lean,Mathlib/Topology/EMetricSpace/Lipschitz.lean	2	4	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	PatrickMassot assignee:PatrickMassot	329-78411 10 months ago	unknown	unknown
12799	jstoobysmith author:jstoobysmith	feat(LinearAlgebra/UnitaryGroup): Add properties of Special Unitary Group	Add properties of the special unitary group, mirroring the properties of found in Algebra/Star/Unitary.lean. In particular, I add an instance of `specialUnitaryGroup` as a `Group`, `Star`, `InvolutiveStar`, and `StarMul`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	please-adopt t-algebra new-contributor merge-conflict awaiting-author label:t-algebra$	78/0	Mathlib/LinearAlgebra/UnitaryGroup.lean	1	8	['chrisflav', 'jcommelin', 'leanprover-community-bot-assistant']	nobody	319-50364 10 months ago	unknown	unknown
20334	miguelmarco author:miguelmarco	feat: allow polyrith to use a local Singular/Sage install	Try to call a local install of Singular (either standalone or inside Sage) to find the witness for polyrith before trying to call the online sage cell server. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict awaiting-author new-contributor t-meta	171/48	Mathlib/Tactic/Polyrith.lean,scripts/polyrith_sage.py	2	16	['eric-wieser', 'github-actions', 'hanwenzhu', 'kim-em', 'miguelmarco', 'mkoeppe']	nobody	312-42917 10 months ago	unknown	unknown
25218	kckennylau author:kckennylau	feat(AlgebraicGeometry): Tate normal form of elliptic curves	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-algebraic-geometry awaiting-zulip new-contributor	291/26	Mathlib.lean,Mathlib/AlgebraicGeometry/EllipticCurve/IsomOfJ.lean,Mathlib/AlgebraicGeometry/EllipticCurve/Modular/TateNormalForm.lean,Mathlib/AlgebraicGeometry/EllipticCurve/NormalForms.lean,Mathlib/AlgebraicGeometry/EllipticCurve/VariableChange.lean	5	31	['MichaelStollBayreuth', 'Multramate', 'acmepjz', 'github-actions', 'grunweg', 'kckennylau', 'leanprover-community-bot-assistant']	nobody	291-39678 9 months ago	unknown	unknown
10190	jstoobysmith author:jstoobysmith	feat(AlgebraicTopology): add Augmented Simplex Category	- Added the definition of the category FinLinOrd of finite linear ordered sets. - Added the definition of the augmented simplex category `AugmentedSimplexCategory`, and showed it is the Skeleton of FinLinOrd. - Showed that the category of augmented simplicial objects defined as a comma category is equivalent to the category of functors from `AugmentedSimplexCategory^\op` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebraic-topology WIP t-category-theory new-contributor merge-conflict	720/0	Mathlib.lean,Mathlib/AlgebraicTopology/AugmentedSimplexCategory.lean,Mathlib/AlgebraicTopology/SimplicialObject.lean,Mathlib/Order/Category/FinLinOrd.lean	4	5	['TwoFX', 'YaelDillies', 'joelriou', 'jstoobysmith']	nobody	265-11818 8 months ago	unknown	unknown
25238	Hagb author:Hagb	feat(Tactic/ComputeDegree): add support for scalar multiplication with different types	It would be able to deal with `a • (X : R[X])` where `a : S` is in a different type `S` with `[SMulZeroClass S R]`. --- - [x] depends on: #25237 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-meta new-contributor	17/5	Mathlib/Tactic/ComputeDegree.lean,MathlibTest/ComputeDegree.lean	2	3	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	261-18009 8 months ago	unknown	unknown
18646	jxjwan author:jxjwan	feat(RingTheory): isotypic components	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-ring-theory new-contributor	308/0	Mathlib/Order/CompactlyGenerated/Basic.lean,Mathlib/RingTheory/Isotypic.lean,Mathlib/RingTheory/SimpleModule.lean	3	1	['github-actions']	nobody	260-20030 8 months ago	unknown	unknown
20671	thefundamentaltheor3m author:thefundamentaltheor3m	feat(Analysis/Asymptotics/SpecificAsymptotics): Proving that 𝛔ₖ(n) = O(nᵏ⁺¹)	This PR proves a result about the $\sigma_k(n)$ arithmetic function, namely, that it is $O\left(n^{k+1}\right)$. Main theorem: `theorem sigma_asymptotic (k : ℕ) : (fun n ↦ (σ k n : ℝ)) =O[atTop] (fun n ↦ (n ^ (k + 1) : ℝ))` This result was proved as part of the sphere packing project. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-number-theory new-contributor large-import merge-conflict awaiting-author	29/0	Mathlib/Analysis/Asymptotics/SpecificAsymptotics.lean	1	3	['b-mehta', 'github-actions', 'mathlib4-merge-conflict-bot']	b-mehta assignee:b-mehta	255-23571 8 months ago	unknown	unknown
22925	ggranberry author:ggranberry	feat(Mathlib/PlaceHolder/ToeplitzHausdorff): Toeplitz-Hausdorff	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	WIP new-contributor will-close-soon awaiting-author help-wanted t-analysis	411/0	Mathlib/PlaceHolder/ToeplitzHausdorff.lean,Mathlib/PlaceHolder/ToeplitzHausdorff_v2.lean	2	11	['faenuccio', 'ggranberry', 'github-actions']	faenuccio assignee:faenuccio	252-15441 8 months ago	unknown	unknown
20722	ctchou author:ctchou	feat(Counterexamples): the Vitali set is non-measurable	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	please-adopt t-measure-probability new-contributor merge-conflict awaiting-author	258/3	Counterexamples.lean,Counterexamples/VitaliSetNotMeasurable.lean,Mathlib/MeasureTheory/Measure/NullMeasurable.lean,docs/1000.yaml	4	76	['ctchou', 'github-actions', 'grunweg', 'mathlib4-merge-conflict-bot', 'vihdzp']	vihdzp assignee:vihdzp	249-13255 8 months ago	unknown	unknown
28502	gilesgshaw author:gilesgshaw	feat(Logic/Basic): avoid unnecessary uses of choice	Certain proofs are modified to remove a dependence on the axoim of choice --- - [ ] depends on: #28623	blocked-by-other-PR new-contributor merge-conflict awaiting-author t-logic	83/74	Mathlib/Logic/Basic.lean	1	7	['Ruben-VandeVelde', 'eric-wieser', 'gilesgshaw', 'github-actions', 'kim-em', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	246-35067 8 months ago	249-20596 249 days ago	0-32456 9 hours
19582	yu-yama author:yu-yama	feat(GroupExtension/Abelian): define `OfMulDistribMulAction.equivH2`	Mainly defines: - `structure GroupExtension.OfMulDistribMulAction N G [MulDistribMulAction G N]`: group extensions of `G` by `N` where the multiplicative action of `G` on `N` is the conjugation - `structure GroupExtension.OfMulDistribMulActionWithSection N G [MulDistribMulAction G N]`: group extensions with specific choices of sections - `def GroupExtension.OfMulDistribMulAction.equivH2`: a bijection between the equivalence classes of group extensions and $H^2 (G, N)$ --- - [x] depends on: #20802 (split PR: contains changes to the `Defs` file) - [x] depends on: #20998 (split PR: mainly adds the `Basic` file) - [ ] depends on: #26670 (split PR: adds the first part of the `Abelian` file) Here is a relevant TODO in Mathlib: https://github.com/leanprover-community/mathlib4/blob/4e9fa40d7c480937e09cd6e47a591bd6f3b8be42/Mathlib/RepresentationTheory/GroupCohomology/LowDegree.lean#L46-L48 I would appreciate your comments. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-algebra blocked-by-other-PR new-contributor label:t-algebra$	750/14	Mathlib.lean,Mathlib/GroupTheory/GroupExtension/Abelian.lean,Mathlib/GroupTheory/GroupExtension/Defs.lean,docs/references.bib	4	5	['YaelDillies', 'erdOne', 'github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	243-71575 8 months ago	unknown	unknown
28095	Equilibris author:Equilibris	Univ generic corec	Draft PR: Adding variable universe corecursor for PFunctor --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict new-contributor	321/70	Mathlib/Data/PFunctor/Multivariate/Basic.lean,Mathlib/Data/PFunctor/Multivariate/M.lean,Mathlib/Data/TypeVec.lean	3	7	['Equilibris', 'alexkeizer', 'github-actions', 'mathlib4-merge-conflict-bot']	nobody	242-56837 7 months ago	unknown	unknown
28150	Equilibris author:Equilibris	chore: clean up proofs typevec proofs	While adding variable universe corecs I found a lot of theorems in typevec that could do with a bit of a clean-up --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-data new-contributor	24/26	Mathlib/Data/TypeVec.lean	1	7	['Equilibris', 'alexkeizer', 'github-actions', 'mathlib4-merge-conflict-bot']	nobody	242-56836 7 months ago	242-56837 242 days ago	13-47613 13 days
27403	MoritzBeroRoos author:MoritzBeroRoos	fix: replace probably erroneous usage of ⬝ (with old \cdot) by · (with \centerdot)	Discussion at [zulip](https://leanprover.zulipchat.com/#narrow/channel/270676-lean4/topic/.5Ccdot.20!.3D.20.5Ccenterdot). Currently the abbreviations \cdot and \centerdot resolve to different, with the naked eye nearly undistinguishable symbols (despite the c in cdot surely standing for center..). This pr replaces instances of ⬝ where · was probably meant. All of the replacement is in comments, except for the file bench_summary.lean which is used for priting the github benchmark results. Since this file is about scientific notation of numbers, sure · was meant to be used, not a rectangle. [Related](https://github.com/leanprover-community/mathlib4/pull/27399) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict new-contributor	195/195	Mathlib/Algebra/ContinuedFractions/Computation/Approximations.lean,Mathlib/Algebra/DirectSum/Idempotents.lean,Mathlib/Algebra/Lie/Derivation/Basic.lean,Mathlib/Algebra/Module/Equiv/Basic.lean,Mathlib/AlgebraicGeometry/EllipticCurve/DivisionPolynomial/Basic.lean,Mathlib/Analysis/Analytic/Constructions.lean,Mathlib/Analysis/CStarAlgebra/CStarMatrix.lean,Mathlib/Analysis/Calculus/ContDiff/Basic.lean,Mathlib/Analysis/Calculus/ContDiff/Bounds.lean,Mathlib/Analysis/Calculus/FDeriv/Symmetric.lean,Mathlib/Analysis/Fourier/FourierTransformDeriv.lean,Mathlib/Analysis/InnerProductSpace/Dual.lean,Mathlib/Analysis/InnerProductSpace/PiL2.lean,Mathlib/Analysis/Normed/Unbundled/InvariantExtension.lean,Mathlib/Analysis/SpecialFunctions/Complex/CircleAddChar.lean,Mathlib/Combinatorics/Configuration.lean,Mathlib/Combinatorics/SimpleGraph/AdjMatrix.lean,Mathlib/Combinatorics/SimpleGraph/LapMatrix.lean,Mathlib/Data/Matrix/Block.lean,Mathlib/Data/Matrix/ConjTranspose.lean,Mathlib/Data/Matrix/Hadamard.lean,Mathlib/Data/Matrix/Mul.lean,Mathlib/Data/Matrix/Notation.lean,Mathlib/Data/Matrix/Reflection.lean,Mathlib/Data/Matrix/RowCol.lean,Mathlib/Data/Matrix/Vec.lean,Mathlib/FieldTheory/PurelyInseparable/PerfectClosure.lean,Mathlib/Geometry/Manifold/GroupLieAlgebra.lean,Mathlib/GroupTheory/Coxeter/Matrix.lean,Mathlib/LinearAlgebra/CrossProduct.lean,Mathlib/LinearAlgebra/Matrix/BilinearForm.lean,Mathlib/LinearAlgebra/Matrix/DotProduct.lean,Mathlib/LinearAlgebra/Matrix/Nondegenerate.lean,Mathlib/LinearAlgebra/Matrix/Orthogonal.lean,Mathlib/LinearAlgebra/Matrix/PosDef.lean,Mathlib/LinearAlgebra/Matrix/SchurComplement.lean,Mathlib/LinearAlgebra/Matrix/SesquilinearForm.lean,Mathlib/LinearAlgebra/Matrix/Trace.lean,Mathlib/LinearAlgebra/Multilinear/Basic.lean,Mathlib/LinearAlgebra/PerfectPairing/Matrix.lean,Mathlib/LinearAlgebra/Projectivization/Constructions.lean,Mathlib/NumberTheory/NumberField/ProductFormula.lean,Mathlib/NumberTheory/SiegelsLemma.lean,Mathlib/RingTheory/DividedPowers/SubDPIdeal.lean,Mathlib/SetTheory/Ordinal/Veblen.lean,Mathlib/Topology/Algebra/Module/Equiv.lean,Mathlib/Topology/Homeomorph/Lemmas.lean,Mathlib/Topology/Instances/Matrix.lean,scripts/bench_summary.lean	49	5	['eric-wieser', 'github-actions', 'grunweg', 'leanprover-community-bot-assistant']	nobody	242-36156 7 months ago	265-12078 265 days ago	7-51497 7 days
27399	MoritzBeroRoos author:MoritzBeroRoos	chore: replace every usage of ⬝ᵥ (with old \cdot) by ·ᵥ (with \centerdot)	Discussion at [zulip](https://leanprover.zulipchat.com/#narrow/channel/270676-lean4/topic/.5Ccdot.20!.3D.20.5Ccenterdot). Currently the abbreviations `\cdot` and `\centerdot` resolve to different, with the naked eye nearly undistinguishable symbols (despite the c in cdot surely standing for `center`..): - `\cdot` gives ⬝ [U+2B1D](https://www.compart.com/en/unicode/U+2B1D) "Black Very Small Square" - `\centerdot` gives · [U+00B7](https://www.compart.com/en/unicode/U+00B7) "Middle Dot" Mathlib mostly uses the `\centerdot` variant, except for the dotProduct notation and some probably unsuspecting people wanting \centerdot but getting \cdot in their comments and 6 uses of a notation using the raw `\cdot` without any subscript at `Mathlib\Topology\Homotopy\Product.lean`. This PR replaces the dot product `⬝ᵥ` with its `\centerdot` counterpart `·ᵥ`. The related PR [here](https://github.com/leanprover/vscode-lean4/pull/639) can then overwrite the `\cdot` abbreviation, to produce the same symbol as the `centerdot` abbreviation does. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict new-contributor	133/133	Mathlib/Analysis/CStarAlgebra/CStarMatrix.lean,Mathlib/Analysis/InnerProductSpace/PiL2.lean,Mathlib/Combinatorics/Configuration.lean,Mathlib/Combinatorics/SimpleGraph/AdjMatrix.lean,Mathlib/Combinatorics/SimpleGraph/LapMatrix.lean,Mathlib/Data/Matrix/Block.lean,Mathlib/Data/Matrix/ConjTranspose.lean,Mathlib/Data/Matrix/Hadamard.lean,Mathlib/Data/Matrix/Mul.lean,Mathlib/Data/Matrix/Notation.lean,Mathlib/Data/Matrix/Reflection.lean,Mathlib/Data/Matrix/RowCol.lean,Mathlib/Data/Matrix/Vec.lean,Mathlib/LinearAlgebra/CrossProduct.lean,Mathlib/LinearAlgebra/Matrix/BilinearForm.lean,Mathlib/LinearAlgebra/Matrix/DotProduct.lean,Mathlib/LinearAlgebra/Matrix/Nondegenerate.lean,Mathlib/LinearAlgebra/Matrix/Orthogonal.lean,Mathlib/LinearAlgebra/Matrix/PosDef.lean,Mathlib/LinearAlgebra/Matrix/SchurComplement.lean,Mathlib/LinearAlgebra/Matrix/SesquilinearForm.lean,Mathlib/LinearAlgebra/Matrix/Trace.lean,Mathlib/LinearAlgebra/PerfectPairing/Matrix.lean,Mathlib/LinearAlgebra/Projectivization/Constructions.lean,Mathlib/Topology/Instances/Matrix.lean	25	6	['MoritzBeroRoos', 'eric-wieser', 'github-actions', 'leanprover-community-bot-assistant']	nobody	241-84388 7 months ago	265-12079 265 days ago	7-53541 7 days
27479	iu-isgood author:iu-isgood	feat: Abel's Binomial Theorem	We have formalized Abel's Binomial Theorem as part of an REU project. There are a few remaining sorrys, but we will finish them soon. I will edit this PR message later according to community rules. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-author t-data new-contributor	326/0	Mathlib/Data/Nat/Choose/AbelBinomial.lean	1	28	['ElifUskuplu', 'FrankieNC', 'github-actions', 'iu-isgood']	nobody	241-84149 7 months ago	unknown	unknown
26462	PSchwahn author:PSchwahn	feat(LinearAlgebra/Projection): add results about inverse of `Submodule.prodEquivOfIsCompl`	Add two theorems `Submodule.prodEquivOfIsCompl_symm_apply` and `Submodule.prodEquivOfIsCompl_symm_add`, which are API for `Submodule.prodEquivOfIsCompl`. We believe these theorems are useful; for example, we have used their statements in a [classification formalization project](https://github.com/LieLean/LowDimSolvClassification). Co-authored by: - [Viviana del Barco](https://github.com/vdelbarc) - [Gustavo Infanti](https://github.com/GuQOliveira) - [Exequiel Rivas](https://github.com/erivas) --- I am not sure whether the `prodEquivOfIsCompl_symm_apply` theorem should be tagged with `@[simp]`; this might lead to confluence issues. Opinions are welcome! [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-author t-algebra new-contributor label:t-algebra$	10/0	Mathlib/LinearAlgebra/Projection.lean	1	7	['PSchwahn', 'github-actions', 'joelriou', 'kckennylau']	joelriou assignee:joelriou	225-55517 7 months ago	226-220 225 days ago	73-38219 73 days
28623	gilesgshaw author:gilesgshaw	feat(Logic/Basic): minor additions and simplification of proofs	Add new theorems and simplify proofs. Specifically, we add the family of related theorems `apply_dite_iff_exists`, `apply_dite_iff_forall`, `apply_ite_iff_and` and `apply_ite_iff_or`. For each other 'family' of theorems in the file that is analogous to the above, we do the following - Simplify proofs where possible, e.g. by appealing to the new theorems - Complete the family, if any of the corresponding four are missing - Rename to ensure consistency with the above pattern ---	merge-conflict t-logic new-contributor	83/55	Archive/Examples/IfNormalization/Result.lean,Archive/Examples/IfNormalization/WithoutAesop.lean,Mathlib/Algebra/ContinuedFractions/Computation/Translations.lean,Mathlib/Algebra/MvPolynomial/Variables.lean,Mathlib/Algebra/Notation/Indicator.lean,Mathlib/LinearAlgebra/Matrix/Rank.lean,Mathlib/Logic/Basic.lean,Mathlib/MeasureTheory/Measure/WithDensity.lean,Mathlib/SetTheory/Ordinal/Notation.lean	9	12	['eric-wieser', 'gilesgshaw', 'github-actions', 'mathlib4-merge-conflict-bot', 'plp127']	awainverse assignee:awainverse	225-4019 7 months ago	225-4020 225 days ago	10-53273 10 days
25778	thefundamentaltheor3m author:thefundamentaltheor3m	feat: Monotonicity of `setIntegral` for nonnegative functions	This PR makes it easier to prove monotonicity of the Bochner integral on sets for nonnegative functions by removing the stronger assumption required by the general monotonicity lemma that both of the functions being compared must be integrable. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-author t-measure-probability new-contributor	8/0	Mathlib/MeasureTheory/Integral/Bochner/Set.lean	1	6	['RemyDegenne', 'github-actions', 'sgouezel', 'thefundamentaltheor3m']	nobody	222-86141 7 months ago	314-7579 314 days ago	0-7890 2 hours
29588	Periecle author:Periecle	feat(Analysis/Complex/Residue): Implement residue theory for complex functions at isolated singularities	# Add basic residue theory for complex functions This PR introduces the residue theory implementation in mathlib. ## Main additions - `HasIsolatedSingularityAt f c`: Predicate for functions with isolated singularities at point `c` - `residue f c hf`: The residue of `f` at isolated singularity `c`, defined via circle integrals - Radius independence: `residue_eq_two_pi_I_inv_smul_circleIntegral` - residue equals normalized circle integral for any valid radius - Holomorphic residues: `residue_of_holomorphic` - functions holomorphic in a neighborhood have zero residue - Simple pole formula: `residue_simple_pole` - for `f(z) = (z-c)⁻¹ * g(z)`, residue equals `g(c)` ## Implementation notes - Builds on existing circle integral infrastructure in `CauchyIntegral.lean` - Uses `Classical.choose` to extract witness radius from isolated singularity condition - Comprehensive documentation with mathematical context and examples - Establishes foundation for residue theorem, argument principle, and other applications ## Examples included - `residue(1/z, 0) = 1` (canonical simple pole) - Radius independence demonstration - Zero residues for holomorphic functions This provides the essential building blocks for complex analysis and first step to formalize residue theory.	awaiting-author t-analysis new-contributor	383/0	Mathlib/Analysis/Complex/Residue/Basic.lean	1	17	['Periecle', 'github-actions', 'hrmacbeth', 'llllvvuu', 'loefflerd']	nobody	210-3219 6 months ago	unknown	unknown
29657	jcreinhold author:jcreinhold	feat(CategoryTheory/MarkovCategory): add Markov categories	This PR adds Markov categories to the category theory library. A Markov category is a symmetric monoidal category where every object has canonical copy and delete morphisms that form commutative comonoids. ## What this gives mathlib In a Markov category, morphisms model probabilistic processes. The copy morphism `X → X ⊗ X` creates perfect correlation (both outputs always equal). The delete morphism `X → I` marginalizes (sums/integrates out variables). This structure captures probability theory categorically. The same theorem proves results for: - Finite probability (stochastic matrices) - Measure theory (Markov kernels) - Kleisli categories of probability monads Fritz (2020) used this to prove categorical versions of Fisher-Neyman, Basu's theorem, and other core statistics results. ## Implementation - `MarkovCategory`: Extends `SymmetricCategory` with canonical comonoid structure - `copyMor X : X ⟶ X ⊗ X` and `delMor X : X ⟶ I` for each object - Coherence axioms: commutativity, counitality, coassociativity - Compatibility with tensor products Key design point: The comonoid structure is canonical (fields of the typeclass), not chosen. This matches the probability interpretation where there's exactly one way to copy/marginalize. ## Examples included 1. Cartesian categories: Every cartesian monoidal category forms a Markov category where copy is the diagonal `x ↦ (x,x)` and delete is the terminal morphism. All morphisms are deterministic. 2. FinStoch: Objects are finite types. Morphisms are stochastic matrices (rows sum to 1). This models finite probability spaces with the usual matrix multiplication for composition. ## Scope and review notes This PR provides the basic structure only. Future PRs would add: - Conditional independence - Sufficient statistics - Connection to measure-theoretic probability - More examples (Kleisli categories, Gaussian categories) I'm neither an expert in this material nor in Lean; I've only read a few papers on Markov categories and have gone through tutorial material in Lean. Please review for mathematical correctness and idiomatic Lean. I kept this PR small to check if mathlib wants this addition and to ensure it meets repository standards. ## Why add this now Markov categories provide a useful abstraction level for probability in type theory. Adding it to mathlib enables future work on categorical probability and statistics. In particular, I'm working on a probabilistic programming library and would like to write some proofs using these constructs. ## References - Fritz, T. (2020). [A synthetic approach to Markov kernels, conditional independence and theorems on sufficient statistics](https://arxiv.org/abs/1908.07021). Advances in Mathematics, 370, 107239. - Cho, K., & Jacobs, B. (2019). [Disintegration and Bayesian inversion via string diagrams](https://arxiv.org/abs/1709.00322). Mathematical Structures in Computer Science, 29(7), 938-971. --- All definitions include docstrings. The PR has tests for the core functionality. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict awaiting-author t-category-theory new-contributor	2414/7	Mathlib.lean,Mathlib/CategoryTheory/Bicategory/Monad/Basic.lean,Mathlib/CategoryTheory/CopyDiscardCategory/Basic.lean,Mathlib/CategoryTheory/CopyDiscardCategory/Deterministic.lean,Mathlib/CategoryTheory/MarkovCategory/Basic.lean,Mathlib/CategoryTheory/MarkovCategory/Cartesian.lean,Mathlib/CategoryTheory/MarkovCategory/FinStoch/Basic.lean,Mathlib/CategoryTheory/MarkovCategory/FinStoch/Braided.lean,Mathlib/CategoryTheory/MarkovCategory/FinStoch/CopyDiscard.lean,Mathlib/CategoryTheory/MarkovCategory/FinStoch/Markov.lean,Mathlib/CategoryTheory/MarkovCategory/FinStoch/Monoidal.lean,Mathlib/CategoryTheory/Monoidal/Bimon_.lean,Mathlib/CategoryTheory/Monoidal/CommComon_.lean,Mathlib/CategoryTheory/Monoidal/Comon_.lean,MathlibTest/CategoryTheory/MarkovCategory.lean,docs/references.bib	16	28	['github-actions', 'jcreinhold', 'joelriou', 'mathlib4-merge-conflict-bot']	nobody	209-4050 6 months ago	214-10174 214 days ago	0-2547 42 minutes
26178	ppls-nd-prs author:ppls-nd-prs	feat(CategoryTheory/Limits): Fubini for products	We show that the product of products is a product indexed by the sigma type. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict awaiting-author t-category-theory new-contributor	17/0	Mathlib/CategoryTheory/Limits/Shapes/Products.lean	1	6	['chrisflav', 'github-actions', 'leanprover-community-bot-assistant', 'ppls-nd-prs', 'robin-carlier']	nobody	205-18263 6 months ago	306-27663 306 days ago	0-45487 12 hours
28630	Antidite author:Antidite	feat(Archive/Imo): right isosceles configuration in the complex plane	feat(Archive/Imo): right isosceles configuration in the complex plane This adds `Archive/Imo/Imo1975Q3.lean`, formalizing a triangle configuration with points A=0, B=1, C=z and auxiliary points R, P, Q built via complex rotations and sine-based scale factors. Main results: * `angle_and_distance`: ∠QRP = π/2 and dist Q R = dist R P. * Key identity `QRP_rot90`: (Q z).z − R.z = e^{iπ/2} · ((P z).z − R.z). Design/Style: * Minimal imports; module docstring; semantic lemma names; all definitions and theorems live under the namespace `IMO.TriangleConfig`. Moves: - (none) Deletions: - (none) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	IMO awaiting-author new-contributor	196/0	Archive.lean,Archive/Imo/Imo1975Q3.lean	2	36	['Antidite', 'LLaurance', 'github-actions', 'jsm28']	jsm28 assignee:jsm28	199-70409 6 months ago	199-70409 199 days ago	46-21614 46 days
29926	jcreinhold author:jcreinhold	feat(CategoryTheory/MarkovCategory): add basic finite stochastic matrices definitions to Markov category	This PR introduces FinStoch, the category of finite stochastic matrices, as a concrete example of a Markov category. This PR builds on #29925, #29939, and #29919 and was split up from #29657. ## Main additions ### 1. Core definitions (`FinStoch/Basic.lean`) - `StochasticMatrix m n`: Matrices where rows sum to 1, representing conditional probabilities P(j\|i) - `FinStoch`: The category with finite types as objects and stochastic matrices as morphisms - `DetMorphism`: Deterministic matrices (exactly one 1 per row) with their underlying functions - Composition: Matrix multiplication preserves row-stochasticity via the Chapman-Kolmogorov equation Key design choices: - Row-stochastic convention: entry (i,j) is P(output=j \| input=i) - Deterministic morphisms tracked separately for structural isomorphisms ### 2. Monoidal structure (`FinStoch/Monoidal.lean`) Implements tensor products modeling independent parallel processes: - Tensor on objects: Cartesian product of finite types - Tensor on morphisms: Kronecker product P((j₁,j₂)\|(i₁,i₂)) = P(j₁\|i₁) × P(j₂\|i₂) - Structural morphisms: Associator, unitors use deterministic permutations - Coherence**: Pentagon and triangle identities verified computationally ## Mathematical significance FinStoch provides the canonical example of a Markov category: - Morphisms: Stochastic matrices/Markov chains - Composition: Chapman-Kolmogorov equation for multi-step transitions - Tensor: Independent parallel processes This models finite probability spaces categorically, where: - Objects represent sample spaces - Morphisms represent probabilistic transitions - Tensor products model independence ## References Fritz (2020) - [ ] depends on: #29925	merge-conflict t-category-theory new-contributor	1437/0	Mathlib.lean,Mathlib/CategoryTheory/CopyDiscardCategory/Basic.lean,Mathlib/CategoryTheory/CopyDiscardCategory/Deterministic.lean,Mathlib/CategoryTheory/MarkovCategory/Basic.lean,Mathlib/CategoryTheory/MarkovCategory/Cartesian.lean,Mathlib/CategoryTheory/MarkovCategory/FinStoch/Basic.lean,Mathlib/CategoryTheory/MarkovCategory/FinStoch/Monoidal.lean,MathlibTest/CategoryTheory/MarkovCategory.lean,docs/references.bib	9	4	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	193-80864 6 months ago	unknown	unknown
16773	arulandu author:arulandu	feat(Probability/Distributions): formalize Beta distribution	Formalize Beta distribution, using Gamma distribution as a reference. Added real-valued beta wrapper, in the manner of gamma. Thanks to @EtienneC30 for help with casting real <-> complex. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict awaiting-author new-contributor t-measure-probability	286/1	Mathlib.lean,Mathlib/Analysis/SpecialFunctions/Gamma/Beta.lean,Mathlib/Probability/Distributions/Beta.lean	3	50	['EtienneC30', 'arulandu', 'github-actions', 'mathlib4-merge-conflict-bot', 'vihdzp']	arulandu assignee:arulandu	193-79714 6 months ago	unknown	unknown
30460	janithamalith author:janithamalith	feat(Nat): add lemma nat_card_orbit_mul_card_stabilizer_eq_card_group	Added a lemma `nat_card_orbit_mul_card_stabilizer_eq_card_group` which is the Nat.card version of MulAction.card_orbit_mul_card_stabilizer_eq_card_group --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-author t-group-theory new-contributor	6/0	Mathlib/GroupTheory/GroupAction/CardCommute.lean	1	17	['github-actions', 'kckennylau', 'plp127', 'tb65536']	tb65536 assignee:tb65536	184-3564 6 months ago	184-3564 184 days ago	8-4679 8 days
25225	xcloudyunx author:xcloudyunx	feat(Combinatorics/SimpleGraph): Eulerian walk in connected graph contains all vertices	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-author t-combinatorics new-contributor	16/0	Mathlib/Combinatorics/SimpleGraph/Trails.lean	1	6	['IvanRenison', 'github-actions', 'vlad902']	kmill assignee:kmill	182-53496 6 months ago	unknown	unknown
30828	DeVilhena-Paulo author:DeVilhena-Paulo	feat: implementation of `Finmap.merge`	The main contribution of this pull request is the implementation of a `merge` function for finite maps (`Finmap`). The construction relies on the definition of a `merge` function for association lists (`AList`). There is also a side (unrelated) contribution on `Mathlib/Data/List/Permutation.lean`: the addition of a theorem about the permutation of a list with a head element (that is, a list of the form `a :: l`). --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data new-contributor	449/3	Mathlib/Data/Finmap.lean,Mathlib/Data/List/AList.lean,Mathlib/Data/List/Permutation.lean,Mathlib/Data/List/Sigma.lean	4	1	['github-actions']	nobody	180-76928 5 months ago	unknown	unknown
28676	sun123zxy author:sun123zxy	feat(NumberTheory/ArithmeticFunction): wrap `Nat.totient` as an `ArithmeticFunction`	This wraps the Euler's totient function `Nat.totient` into a new `ArithmeticFunction` `ϕ`, with some basic identities such as `ϕ * ζ = id` and `μ * id = ϕ.` --- We use the notation `ϕ` to distinguish from `Nat.totient`'s notation `φ`, however this might be controversial. Suggestions are welcome! [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-number-theory new-contributor large-import merge-conflict awaiting-author	45/5	Mathlib/NumberTheory/ArithmeticFunction.lean	1	19	['MichaelStollBayreuth', 'SnirBroshi', 'b-mehta', 'eric-wieser', 'github-actions', 'mathlib4-merge-conflict-bot', 'riccardobrasca', 'sun123zxy']	MichaelStollBayreuth assignee:MichaelStollBayreuth	176-22967 5 months ago	191-84043 191 days ago	47-56312 47 days
30299	franv314 author:franv314	feat(Topology/Instances): Cantor set	Prove that the Cantor set has empty interior and the cardinality of the continuum as discussed on [Zulip](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/A.20few.20results.20about.20the.20Cantor.20set/with/543560670) Moves: - Mathlib.Topology.Instances.CantorSet -> Mathlib.Topology.Instances.CantorSet.Basic --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor merge-conflict file-removed awaiting-author t-topology	355/2	Mathlib.lean,Mathlib/Topology/Instances/CantorSet/Basic.lean,Mathlib/Topology/Instances/CantorSet/Cardinality.lean,Mathlib/Topology/Instances/CantorSet/Lemmas.lean	4	5	['github-actions', 'grunweg', 'kckennylau', 'mathlib4-merge-conflict-bot']	nobody	176-14697 5 months ago	196-83726 196 days ago	0-553 9 minutes
30303	franv314 author:franv314	chore(Topology/Instances): add deprecated module	Add deprecated module to moved Cantor set file. --- - [ ] depends on: #30299 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict blocked-by-other-PR new-contributor	486/124	Mathlib.lean,Mathlib/Topology/Instances/CantorSet.lean,Mathlib/Topology/Instances/CantorSet/Basic.lean,Mathlib/Topology/Instances/CantorSet/Cardinality.lean,Mathlib/Topology/Instances/CantorSet/Lemmas.lean	5	3	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	176-14695 5 months ago	unknown	unknown
29871	zach1502 author:zach1502	feat(Matrix/Transvection): Gauss pivot determinant identity and pivot preservation	This PR adds two lemmas formalizing standard Gaussian pivot identities: * `Matrix.Transvection.listTransvecCol_mul_mul_listTransvecRow_pivot`: After applying the canonical left/right transvection products that clear the last column and row, the pivot (bottom-right) entry of a matrix is unchanged. Marked `@[simp]`. * `Matrix.Transvection.det_eq_detTopLeft_mul_pivot`: If the pivot entry is nonzero, then the determinant of the matrix factors as the determinant of the top-left block times the pivot entry, after performing the canonical transvections. This is the usual Gauss–pivot determinant identity. * Added simple usage tests in `MathlibTest/matrix.lean` to check that the new lemmas are usable by `simp`/`simpa`. --- --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-author t-algebra new-contributor label:t-algebra$	94/0	Mathlib/LinearAlgebra/Matrix/Transvection.lean,MathlibTest/matrix.lean	2	3	['github-actions', 'riccardobrasca', 'zach1502']	nobody	170-14218 5 months ago	170-14218 170 days ago	41-49475 41 days
30158	nicolaviolette author:nicolaviolette	feat: combinatorics simplegraph basic	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-author t-combinatorics new-contributor	9/4	Mathlib/Combinatorics/SimpleGraph/Basic.lean	1	3	['b-mehta', 'github-actions']	b-mehta assignee:b-mehta	169-33748 5 months ago	169-33748 169 days ago	31-68997 31 days
26901	5hv5hvnk author:5hv5hvnk	feat: a simproc version of `compute_degree`	Wrap `compute_degree` in a simproc for use by simp. Closes #22219. ---	awaiting-CI new-contributor merge-conflict awaiting-author t-meta	198/0	Mathlib.lean,Mathlib/Tactic/Simproc/PolynomialDegree.lean,MathlibTest/polynomial_degree_simproc.lean	3	19	['5hv5hvnk', 'YaelDillies', 'adomani', 'github-actions', 'mathlib4-merge-conflict-bot']	nobody	166-80416 5 months ago	unknown	unknown
30150	imbrem author:imbrem	feat(CategoryTheory/Monoidal): to_additive for MonoidalCategory	Add `AddMonoidalCategory`, the additive version of `MonoidalCategory`. To get this to work, I needed to _remove_ the `to_additive` attributes in `Discrete.lean`, since existing code relies on the `AddMonoid M → MonoidalCategory M` instance. For now, we simply implement the additive variants by hand instead. --- As discussed in #28718; I added an `AddMonoidalCategory` struct and tagged `MonoidalCategory` with `to_additive`, along with the lemmas in `Category.lean`. I think this is the right approach, since under this framework the "correct" additive version of `Discrete.lean` would be mapping an `AddMonoid` to an `AddMonoidalCategory`. Next steps would be to: - Make `monoidal_coherence` and `coherence` support `AddMonoidalCategory` - Add `CocartesianMonoidalCategory` extending `AddMonoidalCategory` [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-category-theory large-import new-contributor merge-conflict awaiting-zulip t-meta	444/125	Mathlib/CategoryTheory/Monoidal/Category.lean,Mathlib/CategoryTheory/Monoidal/Discrete.lean,Mathlib/Tactic/ToAdditive/GuessName.lean	3	22	['JovanGerb', 'YaelDillies', 'github-actions', 'imbrem', 'mathlib4-merge-conflict-bot']	nobody	160-43407 5 months ago	200-22073 200 days ago	0-29227 8 hours
15651	TpmKranz author:TpmKranz	feat(Computability/NFA): operations for Thompson's construction	Lays the groundwork for a proof of equivalence of RE and NFA, w.r.t. described language. Actual connection to REs comes later, after the groundwork for the opposite direction has been laid. Third chunk of #12648 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-computability merge-conflict awaiting-author awaiting-zulip	307/5	Mathlib/Computability/NFA.lean	1	27	['TpmKranz', 'YaelDillies', 'dupuisf', 'github-actions', 'leanprover-community-bot-assistant', 'meithecatte', 'rudynicolop']	nobody	155-60539 5 months ago	unknown	unknown
15649	TpmKranz author:TpmKranz	feat(Computability): introduce Generalised NFA as bridge to Regular Expression	Lays the groundwork for a proof of equivalence of NFA and RE, w.r.t. described language. Actual connection to NFA comes later, after the groundwork for the opposite direction has been laid. Second chunk of #12648 --- - [x] depends on: #15647 [Data.FinEnum.Option unchanged since then] [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-computability merge-conflict awaiting-author awaiting-zulip	298/0	Mathlib.lean,Mathlib/Computability/GNFA.lean,Mathlib/Computability/Language.lean,Mathlib/Computability/RegularExpressions.lean,docs/references.bib	5	7	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'meithecatte', 'trivial1711']	nobody	154-76780 5 months ago	unknown	unknown
5919	MithicSpirit author:MithicSpirit	feat: implement orthogonality for AffineSubspace	Define `AffineSubspace.orthogonal` and `AffineSubspace.IsOrtho`, as well as develop an API emulating that of `Submodule.orthogonal` and `Submodule.IsOrtho`, respectively. Additionally, provide some relevant lemmas exclusive to affine subspaces, which are mostly to do with the relationship between orthogonality and `AffineSubspace.Parallel`. Closes #5539 --- Still WIP as I need to add more docstrings as well as notations for the new definitions. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	WIP new-contributor merge-conflict help-wanted t-analysis	287/0	Mathlib.lean,Mathlib/Analysis/InnerProductSpace/AffineSubspace.lean	2	7	['MithicSpirit', 'eric-wieser', 'github-actions', 'leanprover-community-bot-assistant', 'mathlib4-merge-conflict-bot']	MithicSpirit assignee:MithicSpirit	154-28237 5 months ago	unknown	unknown
13442	dignissimus author:dignissimus	feat: mabel tactic for multiplicative abelian groups	Mabel tactic for multiplicative abelian groups (#10361) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor merge-conflict modifies-tactic-syntax awaiting-author help-wanted t-meta	439/0	Mathlib.lean,Mathlib/Tactic.lean,Mathlib/Tactic/MAbel.lean,MathlibTest/mabel.lean	4	11	['BoltonBailey', 'dignissimus', 'github-actions', 'joneugster', 'kbuzzard', 'mathlib4-merge-conflict-bot']	joneugster assignee:joneugster	154-27973 5 months ago	unknown	unknown
14237	js2357 author:js2357	feat: Define the localization of a fractional ideal at a prime ideal	Define the localization of a fractional ideal at a prime ideal, and prove some basic properties. --- This PR is part 3 out of 4 of a proof of `isDedekindDomain_iff_isDedekindDomainDvr`. Part 4 is available here: #14242 - [x] depends on: #14099 Part 1 - [x] depends on: #14216 Part 2 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict awaiting-author t-algebra new-contributor label:t-algebra$	230/0	Mathlib.lean,Mathlib/RingTheory/FractionalIdeal/LocalizedAtPrime.lean,Mathlib/RingTheory/Localization/Basic.lean	3	22	['Vierkantor', 'YaelDillies', 'github-actions', 'js2357', 'kbuzzard', 'leanprover-community-bot-assistant', 'leanprover-community-mathlib4-bot', 'mathlib4-merge-conflict-bot']	Vierkantor assignee:Vierkantor	154-27971 5 months ago	unknown	unknown
15224	AnthonyBordg author:AnthonyBordg	feat(CategoryTheory/Sites): covering families and their associated Grothendieck topology	Define covering families on a category and their associated Grothendieck topology by using the API for `Coverage`. Give an explicit characterization of the covering sieves of the said topology. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict awaiting-author t-category-theory new-contributor	112/0	Mathlib.lean,Mathlib/CategoryTheory/Sites/CoveringFamilies.lean	2	21	['AnthonyBordg', 'adamtopaz', 'dagurtomas', 'github-actions', 'joelriou', 'mathlib4-merge-conflict-bot']	nobody	154-27842 5 months ago	unknown	unknown
17587	kmill author:kmill	feat: Sym2-as-Finset theory	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-data new-contributor	105/3	Mathlib/Combinatorics/SimpleGraph/Basic.lean,Mathlib/Combinatorics/SimpleGraph/Finite.lean,Mathlib/Data/Sym/Sym2.lean,Mathlib/RingTheory/Polynomial/Vieta.lean	4	11	['FordUniver', 'YaelDillies', 'github-actions', 'kmill', 'mathlib4-merge-conflict-bot']	nobody	154-27688 5 months ago	unknown	unknown
18630	tomaz1502 author:tomaz1502	feat(Computability.Timed): Formalization of runtime complexity of List.mergeSort	This PR adds the formalization of the runtime complexity of the merge sort algorithm, defined in `Data/List/Sort`. Requires: https://github.com/leanprover-community/mathlib4/pull/15451 References: - Previous PR on mathlib3: https://github.com/leanprover-community/mathlib3/pull/14494/ - First discussion on Zulip: https://leanprover.zulipchat.com/#narrow/stream/113488-general/topic/BSc.20Final.20Project/near/220647062 - Second disussion on Zulip: https://leanprover.zulipchat.com/#narrow/stream/113488-general/topic/Formalization.20of.20Runtime.20Complexity.20of.20Sorting.20Algorithms/near/284184450 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-computability new-contributor	526/0	Mathlib.lean,Mathlib/Computability/Timed/InsertionSort.lean,Mathlib/Computability/Timed/Merge.lean,Mathlib/Computability/Timed/MergeSort.lean,Mathlib/Computability/Timed/Split.lean	5	9	['github-actions', 'mathlib4-merge-conflict-bot']	nobody	154-27686 5 months ago	unknown	unknown
20648	anthonyde author:anthonyde	feat: formalize regular expression -> εNFA	The file `Computability/RegularExpressionsToEpsilonNFA.lean` contains a formal definition of Thompson's method for constructing an `εNFA` from a `RegularExpression` and a proof of its correctness. --- - [x] depends on: #20644 - [x] depends on: #20645 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-computability awaiting-zulip new-contributor	490/0	Mathlib.lean,Mathlib/Computability/RegularExpressionsToEpsilonNFA.lean,docs/references.bib	3	7	['anthonyde', 'github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'meithecatte', 'qawbecrdtey']	nobody	154-27548 5 months ago	unknown	unknown
21903	yhtq author:yhtq	feat: add from/toList between `FreeSemigroup` and `List` with relative theorems	Add from/toList between `FreeSemigroup` and `List` with relative theorems, as well as an incidental definition of lexicographic order on `FreeSemigroup`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra new-contributor awaiting-CI large-import merge-conflict label:t-algebra$	169/0	Mathlib/Algebra/Free.lean	1	12	['YaelDillies', 'github-actions', 'mathlib4-merge-conflict-bot']	nobody	154-27408 5 months ago	unknown	unknown
22159	shetzl author:shetzl	feat: add definition of pushdown automata	Add the definition of pushdown automata and their two acceptance conditions: acceptance based on empty stack and acceptance based on final state. Co-authored-by: Tobias Leichtfried --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-computability awaiting-author new-contributor	70/0	Mathlib.lean,Mathlib/Computability/PDA.lean	2	35	['YaelDillies', 'github-actions', 'madvorak', 'mathlib4-merge-conflict-bot', 'shetzl']	nobody	154-27402 5 months ago	unknown	unknown
22302	658060 author:658060	feat: add `CategoryTheory.Topos.Power`	This is a continuation of #21281 with the end goal of defining topoi in Mathlib. It introduces the notion of a power object in a category with a subobject classifier, which is a special case of an internal hom. The definition `HasPowerObjects C` contained in this PR is all that remains before `IsTopos C` can be defined. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict awaiting-author t-category-theory new-contributor	312/0	Mathlib.lean,Mathlib/CategoryTheory/Topos/Power.lean	2	3	['github-actions', 'joelriou', 'mathlib4-merge-conflict-bot']	b-mehta assignee:b-mehta	154-27393 5 months ago	unknown	unknown
22790	mhk119 author:mhk119	feat: Extend `taylor_mean_remainder_lagrange` to `x < x_0`	The `taylor_mean_remainder_lagrange` theorem has the assumption that $x_0 < x$. In many applications, we need $x < x_0$ and one cannot use the current version to obtain this (see [zulip](https://leanprover.zulipchat.com/#narrow/channel/116395-maths/topic/Taylor's.20theorem)). This PR introduces a set of theorems that push negations through Taylor expansions so that one can extend `taylor_mean_remainder_lagrange` to the case when $x < x_0$. These theorems should also be useful elsewhere since they are quite general.	merge-conflict awaiting-author t-analysis new-contributor	111/1	Mathlib/Analysis/Calculus/Deriv/Basic.lean,Mathlib/Analysis/Calculus/IteratedDeriv/Lemmas.lean,Mathlib/Analysis/Calculus/Taylor.lean	3	13	['Paul-Lez', 'github-actions', 'grunweg', 'mathlib4-merge-conflict-bot', 'mhk119']	nobody	154-27380 5 months ago	unknown	unknown
24333	xcloudyunx author:xcloudyunx	feat(Combinatorics/SimpleGraph): cycle graph implementation for generic vertex types	The existing `cycleGraph` implementation under Combinatorics/SimpleGraph/Circulant.lean only operates over `Fin n`. This PR implements a cycle graph implementation over any generic vertex type. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict awaiting-author t-combinatorics new-contributor	187/0	Mathlib.lean,Mathlib/Combinatorics/SimpleGraph/Cycle.lean	2	42	['IvanRenison', 'github-actions', 'mathlib4-merge-conflict-bot', 'vlad902']	kmill assignee:kmill	154-27227 5 months ago	unknown	unknown
25739	literandltx author:literandltx	feat(NumberTheory/LegendreSymbol): Add sqrt‐of‐residue theorems for p=4k+3 and p=8k+5	Add a new file `QuadraticResidueRoots.lean` under `Mathlib/NumberTheory/LegendreSymbol/` that proves two explicit “square-root of quadratic residue” theorems for primes of the specific form. - `exists_sqrt_of_residue_mod4_eq3` for primes `p = 4k + 3` - `exists_sqrt_of_residue_mod8_eq5`* for primes `p = 8*k + 5` It also introduces the helper lemmas `euler_criterion_traditional` and `legendreSym.at_two_mod8_eq_5`. Import lines in `Mathlib.lean` and `Mathlib/NumberTheory/LegendreSymbol/Basic.lean` have been updated accordingly.	merge-conflict awaiting-author t-number-theory new-contributor	217/0	Mathlib.lean,Mathlib/NumberTheory/LegendreSymbol/Basic.lean,Mathlib/NumberTheory/LegendreSymbol/QuadraticReciprocity.lean,Mathlib/NumberTheory/LegendreSymbol/QuadraticResidueRoots.lean	4	3	['github-actions', 'kckennylau', 'mathlib4-merge-conflict-bot']	literandltx assignee:literandltx	154-27078 5 months ago	unknown	unknown
26300	igorkhavkine author:igorkhavkine	feat(Analysis/Calculus/FDeriv): continuous differentiability from continuous partial derivatives on an open domain in a product space	If a function `f : E × F → G` is continuously differentiable, then its partial derivatives along `E` and `F` are also continuous. The non-trivial converse implication holds when the partial derivatives are continuous on an open domain, and they can be added together to give the total derivative of `f`. See this [#mathlib4 > Partial derivatives @ 💬](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Partial.20derivatives/near/520995477) and the containing thread for some discussion. The PR creates a new import (`Mathlib.Analysis.Calculus.FDeriv.Partial`), where other results about partial derivatives could go in the future. --- this is the migration of #25304 to the PR-from-fork workflow - [x] depends on: #25564 - [x] depends on: #26273 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	WIP new-contributor merge-conflict awaiting-author t-analysis	468/0	Mathlib.lean,Mathlib/Analysis/Calculus/FDeriv/Partial.lean,Mathlib/Analysis/Normed/Operator/BoundedLinearMaps.lean	3	21	['YaelDillies', 'agjftucker', 'github-actions', 'igorkhavkine', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'sgouezel']	sgouezel assignee:sgouezel	154-26866 5 months ago	250-75256 250 days ago	44-74030 44 days
26594	metakunt author:metakunt	feat(Algebra/Polynomial/ZMod): Add Polynomial.equiv_of_nat_of_polynomial_zmod	This adds an explicit bijection between the naturals and $$\mathbb{Z}/n\mathbb{Z}[X]$$ in a canonical way. --- I feel that some API is missing to make the theorem shorter, I have no idea what lemmas to extract though. Also I don't know when to use spaces and when not, so I did it best effort.	merge-conflict awaiting-author t-algebra new-contributor label:t-algebra$	465/0	Mathlib.lean,Mathlib/Algebra/Polynomial/ZMod.lean	2	3	['Ruben-VandeVelde', 'github-actions', 'mathlib4-merge-conflict-bot']	nobody	154-26718 5 months ago	269-70476 269 days ago	25-4678 25 days
26757	fweth author:fweth	feat(CategoryTheory/Topos): define elementary topos	This commit begins the formalization of the notion of an elementary topos, following the definition in \[Mac Lane & Moerdijk, Sheaves in Geometry and Logic (1992), Ch. IV, Section 1]. It introduces the file `Mathlib/CategoryTheory/Topos/Basic.lean`, which currently includes: * The definition of an elementary topos. * Proof that the power object map is a functor * Theorem about pullbacks of characterstic maps Subobject classifiers, which are used in the definition, have already been defined in `CategoryTheory/Topos/Classifier.lean` Work in progress: further formalization of the section is planned. Questions: * Should the definition of power objects be separated into its own file/module, perhaps under `CategoryTheory/Topos/PowerObject.lean`? * Is the notation `P` / `P_morph` / `P_functor` for the power object functor on objects / morphisms / total acceptable? * Should the comments and docstrings rather use the notation from the book, where `g ∘ f` denotes arrow composition from righ to left, or the Lean variant `f ≫ g`? Klaus Gy klausgy@gmail.com --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict awaiting-author t-category-theory new-contributor	401/66	Mathlib.lean,Mathlib/CategoryTheory/Closed/PowerObjects.lean,Mathlib/CategoryTheory/Limits/Shapes/BinaryProducts.lean,Mathlib/CategoryTheory/Limits/Shapes/Equalizers.lean,Mathlib/CategoryTheory/Limits/Shapes/Pullback/CommSq.lean,Mathlib/CategoryTheory/Limits/Shapes/Pullback/Equalizer.lean,Mathlib/CategoryTheory/Monoidal/Cartesian/Basic.lean,Mathlib/CategoryTheory/Subobject/Basic.lean,Mathlib/CategoryTheory/Topos/Classifier.lean	9	17	['fweth', 'github-actions', 'joelriou', 'leanprover-community-bot-assistant', 'mathlib4-merge-conflict-bot']	joelriou assignee:joelriou	154-26713 5 months ago	183-79732 183 days ago	61-75483 61 days
27155	Pjotr5 author:Pjotr5	feat: Shearer's bound on the independence number of triangle free graphs	I added the file IndependenceNumber.lean to the Mathlib.Combinatorics.SimpleGraph.Triangle folder. It contains a proof of a theorem by Shearer on the independence number of triangle-free graphs . I was told this might be useful to add to Mathlib a Zullip thread linked [here](https://leanprover.zulipchat.com/#narrow/channel/217875-Is-there-code-for-X.3F/topic/Convexity.20of.20a.20specific.20function/with/510469526). I tried to comply as much as I could with the Mathlib style guide, but I realise that there is probably still a significant amount of editing to be done. For one thing: there are probably some lemmas and theorems in there that might be better suited in other files, but since this is my first PR I though I would all put it in one file before starting to edit a bunch of files. I was also advised to split up the file into multiple smaller PRs, but since everything is basically serving this one proof I could not really find a natural way to do that. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict awaiting-author t-combinatorics new-contributor	1266/0	Mathlib.lean,Mathlib/Combinatorics/SimpleGraph/Triangle/IndependenceNumber.lean	2	10	['Pjotr5', 'github-actions', 'grunweg', 'mathlib4-merge-conflict-bot']	nobody	154-26676 5 months ago	unknown	unknown
27753	YunkaiZhang233 author:YunkaiZhang233	feat(CategoryTheory): implemented proofs for factorisation categories being equivalent to iterated comma categories in two ways	--- Completed one of the tasks in TODOs, shown and implemented the details for (X/C)/f ≌ Factorisation f ≌ f/(C/Y). This is migrated from my previous PR #22390 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict awaiting-author t-category-theory new-contributor	70/1	Mathlib/CategoryTheory/Category/Factorisation.lean	1	13	['YunkaiZhang233', 'b-mehta', 'github-actions', 'mathlib4-merge-conflict-bot', 'robin-carlier']	nobody	154-26521 5 months ago	264-84084 264 days ago	0-2875 47 minutes
27850	fyqing author:fyqing	feat: 0-dimensional manifolds are discrete and countable	This is the converse direction of the classification of 0-dimensional manifolds. The other direction was shown in #22105. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict awaiting-author t-differential-geometry new-contributor	80/0	Mathlib.lean,Mathlib/Geometry/Manifold/ZeroDim.lean	2	14	['fyqing', 'github-actions', 'grunweg', 'mathlib4-merge-conflict-bot', 'tb65536']	grunweg assignee:grunweg	154-26519 5 months ago	263-58746 263 days ago	0-3675 1 hour
28125	nonisomorphiclinearmap author:nonisomorphiclinearmap	feat(Combinatorics): basic definition of simplicial complexes	This PR introduces the basic definition of a finite (abstract) simplicial complex, located in Mathlib/Combinatorics/SimplicialComplex/Basic.lean. --- This is our first contribution to mathlib. This work was done as part of the Fields Institute Summer Undergraduate Program on formalization in topological combinatorics. Eventually, we aim to formalize Lovasz's proof of the Kneser Conjecture and this is a small stepping stone in that direction. Some other commits will shortly depend on this one. We would like to acknowledge the Fields Institute for Research in Mathematical Sciences for their sponsorship. We would also like to thank our supervisors, Professor Chris Kapulkin and Mr. Daniel Carranza, for their guidance and support throughout this project. We would also like to thank our group members Tom Lindquist and Quang Minh Nguyen for our fruitful discussions.	merge-conflict t-combinatorics new-contributor	374/0	Mathlib.lean,Mathlib/Combinatorics/SimplicialComplex/Basic.lean,Mathlib/Combinatorics/SimplicialComplex/Category.lean,Mathlib/Combinatorics/SimplicialComplex/FacePoset.lean,Mathlib/Combinatorics/SimplicialComplex/Hom.lean	5	2	['github-actions', 'mathlib4-merge-conflict-bot']	awainverse assignee:awainverse	154-26387 5 months ago	154-26388 154 days ago	99-48372 99 days
28530	nonisomorphiclinearmap author:nonisomorphiclinearmap	feat(Combinatorics/SimplicialComplex/Topology): add standard simplices and geometric realisation (colimit + functoriality)	Introduce the standard simplex on a finite vertex set and build the geometric realisation \|X\| of a simplicial complex. Prove that \|X\| is the colimit of the face diagram δ_X : X.faces ⥤ TopCat, and define the induced map on realisations \|φ\| : \|X\| ⟶ \|Y\| for a simplicial map φ. Show that the abstract map from colimit functoriality agrees with the concrete push-forward of barycentric coordinates. Package these into a functor SimplicialComplexCat ⥤ TopCat. --- This is our first contribution to mathlib. This work was done as part of the Fields Institute Summer Undergraduate Program on formalization in topological combinatorics. Eventually, we aim to formalize Lovasz's proof of the Kneser Conjecture and this lays the groundwork to do this. We would like to acknowledge the Fields Institute for Research in Mathematical Sciences for their sponsorship. We would also like to thank our supervisors, Professor Chris Kapulkin and Mr. Daniel Carranza, for their guidance and support throughout this project. I would also like to thank our group members Sebastian Kumar, Tom Lindquist and Quang Minh Nguyen for our fruitful discussions. - [ ] depends on: #28125	merge-conflict blocked-by-other-PR t-combinatorics new-contributor	1826/0	Mathlib.lean,Mathlib/Combinatorics/SimplicialComplex/Basic.lean,Mathlib/Combinatorics/SimplicialComplex/Category.lean,Mathlib/Combinatorics/SimplicialComplex/FacePoset.lean,Mathlib/Combinatorics/SimplicialComplex/Hom.lean,Mathlib/Combinatorics/SimplicialComplex/Topology/GeomReal/Basic.lean,Mathlib/Combinatorics/SimplicialComplex/Topology/GeomReal/Colimit.lean,Mathlib/Combinatorics/SimplicialComplex/Topology/GeomReal/Diagram.lean,Mathlib/Combinatorics/SimplicialComplex/Topology/GeomReal/Functor.lean,Mathlib/Combinatorics/SimplicialComplex/Topology/GeomReal/Map.lean,Mathlib/Combinatorics/SimplicialComplex/Topology/Simplex.lean,Mathlib/Combinatorics/SimplicialComplex/Topology/SimplexMap.lean	12	3	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	154-26373 5 months ago	unknown	unknown
28871	JaafarTanoukhi author:JaafarTanoukhi	feat(Combinatorics/Digraph): Tournaments	Define orientations and tournaments. Related to #26771. Co-authored-by: Rida Hamadani --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-combinatorics new-contributor	62/0	Mathlib.lean,Mathlib/Combinatorics/Digraph/Orientation.lean,Mathlib/Combinatorics/Digraph/Tournament.lean	3	6	['JaafarTanoukhi', 'Rida-Hamadani', 'SnirBroshi', 'github-actions', 'mathlib4-merge-conflict-bot']	kmill assignee:kmill	154-26234 5 months ago	154-26235 154 days ago	55-54921 55 days
29947	JaafarTanoukhi author:JaafarTanoukhi	feat(Combinatorics/Digraph): Maps	Ported `SimpleGraph/Maps.lean` to `Digraph/Maps.lean` for future PRs related to issue #[26771](https://github.com/leanprover-community/mathlib4/issues/26771) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-combinatorics new-contributor	476/0	Mathlib.lean,Mathlib/Combinatorics/Digraph/Maps.lean	2	2	['github-actions', 'mathlib4-merge-conflict-bot']	awainverse assignee:awainverse	154-25600 5 months ago	154-25601 154 days ago	54-81855 54 days
30230	CoolRmal author:CoolRmal	feat(MeasureTheory): Basic properties of the integral against a vector measure with a bilinear form.	Create a folder named Integral in the folder about vector measures. Define the integral of a function against a vector measure with a bilinear form, and prove that integral is a linear operator on functions, bilinear forms, and vector measures, respectively. Several useful lemmas are added into the file about variations of a vector measure (e.g. triangle inequality). --- - [ ] depends on: #28499 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict blocked-by-other-PR new-contributor t-measure-probability	1353/0	Mathlib.lean,Mathlib/MeasureTheory/VectorMeasure/Basic.lean,Mathlib/MeasureTheory/VectorMeasure/Integral/Basic.lean,Mathlib/MeasureTheory/VectorMeasure/Integral/L1.lean,Mathlib/MeasureTheory/VectorMeasure/Variation/Defs.lean,Mathlib/MeasureTheory/VectorMeasure/Variation/Lemmas.lean	6	3	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	154-25431 5 months ago	unknown	unknown
14704	Command-Master author:Command-Master	feat(FieldTheory): define typeclass for simple extensions, and prove some properties	Define `SimpleExtension F K`, which says that `K` is a simple field extension of `F`, and show that together with transcendentality it implies `IsFractionRing F[X] K`. --- - [x] depends on: #14710 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	WIP t-algebra new-contributor merge-conflict awaiting-author label:t-algebra$	120/0	Mathlib.lean,Mathlib/FieldTheory/SimpleExtension.lean	2	19	['Command-Master', 'acmepjz', 'github-actions', 'leanprover-community-mathlib4-bot', 'mathlib4-merge-conflict-bot', 'tb65536']	nobody	154-22432 5 months ago	unknown	unknown
11021	jstoobysmith author:jstoobysmith	feat(AlgebraicTopology): add join of augmented SSets	This pull-request adds the definition of the join of augmented SSets defined as contravariant functors from `WithInitial SimplexCategory` to `Type u`. In addition it shows that the join of two standard augmented SSets is again an augmented SSets. From this the definition of the join of simplicial sets should follow easily. To aid the above theory, an api for `WithInitial SimplexCategory` has been created, with the notion of the `join` and `split` (forming a sort of inverse to join) of objects in this category are defined. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict WIP t-algebraic-topology new-contributor	2137/1	.gitignore,Mathlib.lean,Mathlib/AlgebraicTopology/Join.lean,Mathlib/AlgebraicTopology/SimplexCategory.lean,Mathlib/AlgebraicTopology/SimplexCategoryWithInitial.lean,Mathlib/AlgebraicTopology/SimplicialSet.lean	6	47	['github-actions', 'jcommelin']	nobody	153-85848 5 months ago	unknown	unknown
18626	hannahfechtner author:hannahfechtner	feat: define Artin braid groups	Define the Artin braid group on infinitely many strands. Includes a toGroup function which defines a function out of the braid group to any other group (given a function which satisfies the braid relations) (more to come in this file; next up: Artin braid groups on finitely many strands) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict awaiting-author t-algebra new-contributor label:t-algebra$	91/0	Mathlib.lean,Mathlib/GroupTheory/SpecificGroups/BraidGroup/Basic.lean	2	22	['github-actions', 'hannahfechtner', 'jcommelin', 'joelriou']	nobody	153-85695 5 months ago	unknown	unknown
20029	FrederickPu author:FrederickPu	feat(Tactic/simps): allow for Config attributes to be set directly	Allow for Config attributes to be set directly when using initialize_simp_projection as per issue #19895 Basically modified initialize_simp_projection so that the user has the option of specifying a tuple of config option values. Ex: ``` initialize_simp_projection MulEquiv (toFun → apply, invFun → symm_apply) (fullyApplied := false) ``` These config options are then converted into projections. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict WIP new-contributor t-meta	34/4	Mathlib/Tactic/Simps/Basic.lean	1	11	['FrederickPu', 'YaelDillies', 'fpvandoorn', 'github-actions', 'leanprover-community-bot-assistant']	nobody	153-85632 5 months ago	unknown	unknown
21269	658060 author:658060	feat(CategoryTheory/Topos): basic definitions and results in topos theory	This code contains basic definitions and results in topos theory, including the definition of a subobject classifier, power objects, and topoi. It is proved that every topos has exponential objects, i.e. "internal homs". The mathematical content follows chapter IV sections 1-2 of Mac Lane and Moerdijk's text "Sheaves in Geometry and Logic". --- - [x] depends on: #21281 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	WIP t-category-theory new-contributor merge-conflict awaiting-author	1269/0	Mathlib.lean,Mathlib/CategoryTheory/Topos/Basic.lean,Mathlib/CategoryTheory/Topos/Classifier.lean,Mathlib/CategoryTheory/Topos/Exponentials.lean,Mathlib/CategoryTheory/Topos/Power.lean	5	10	['658060', 'gio256', 'github-actions', 'joelriou', 'mathlib4-dependent-issues-bot']	nobody	153-85605 5 months ago	unknown	unknown
23990	robertmaxton42 author:robertmaxton42	feat(Types.Colimits): Quot is functorial and colimitEquivQuot is natural	Add `Functor.quotFunctor` to parallel `Functor.sectionsFunctor`, witnessing that `Quot` is functorial; add `colimNatIsoQuotFunctor` to parallel `limNatIsoSectionsFunctor`, witnessing that `colimitEquivQuot` is natural in the diagram $F$. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict awaiting-author t-category-theory new-contributor	33/0	Mathlib/CategoryTheory/Limits/Types/Colimits.lean	1	5	['github-actions', 'joelriou', 'leanprover-community-bot-assistant', 'robertmaxton42']	nobody	153-85488 5 months ago	unknown	unknown
27991	sinianluoye author:sinianluoye	feat(Rat): add Rat.den_eq_of_add_den_eq_one and its dependent lemmas	```lean4 example {q r : ℚ} (h : (q + r).den = 1) : q.den = r.den := by ``` It is so simple, but I couldn't find it in current mathlib repo. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-author t-data new-contributor	22/0	Mathlib/Data/Rat/Lemmas.lean	1	33	['github-actions', 'kim-em', 'mathlib-bors', 'pechersky', 'sinianluoye', 'themathqueen']	pechersky assignee:pechersky	153-85171 5 months ago	185-22365 185 days ago	74-50277 74 days
28215	5hv5hvnk author:5hv5hvnk	feat: strong and Weak connectivity for Digraphs	strong and weak connectivity in Digraphs --- Should resolve a part of issue #26771 Main additions in the PR: 1. Walks in Digraphs (Walk.lean) - Basic walk structure with start and end vertices - Support for walk operations: append, reverse, length - Support functions: getVert, copy, support 2. Walk Decompositions (WalkDecomp.lean) - takeUntil and dropUntil functions to split walks - rotate operation for loop walks - Theorems relating to walk decomposition properties 3. Subgraphs (subgraph.lean) - Subgraph structure for digraphs - Induced and spanning subgraph predicates - Lattice structure (sup, inf, top, bot) - Coercion to standalone digraphs 4. Paths (Paths.lean) - Trail, Path, Circuit, Cycle definitions - Path structure with no repeating vertices - Theorems relating different path types - Basic connectivity definitions (reachable, weakly/strongly connected) 5. Connectivity (Connected.lean) - Reachability relations and properties - Strong and weak connectivity definitions - Connected component types: - StronglyConnectedComponent - WeaklyConnectedComponent - ConnectedComponent - Component properties and equivalence relations --> [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	WIP new-contributor merge-conflict awaiting-author t-combinatorics	1266/0	Mathlib.lean,Mathlib/Combinatorics/Digraph/Connected.lean,Mathlib/Combinatorics/Digraph/Paths.lean,Mathlib/Combinatorics/Digraph/Subgraph.lean,Mathlib/Combinatorics/Digraph/Walk.lean,Mathlib/Combinatorics/Digraph/WalkDecomp.lean	6	4	['github-actions', 'grunweg', 'mathlib4-merge-conflict-bot']	nobody	153-85150 5 months ago	unknown	unknown
29574	JarodAlper author:JarodAlper	feat: regular local rings are domains	We have added three new files in Mathlib/RingTheory/LocalRing * EmbeddingDimension.lean * LocalRingDimension.lean * RegularLocalRings.lean We have added two lemmas and an instance in Mathlib/RingTheory/LocalRing/RingHom/Basic.lean This work was done by Jarod Alper and Brian Nugent. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-ring-theory new-contributor	910/3	Mathlib.lean,Mathlib/RingTheory/LocalRing/EmbeddingDimension.lean,Mathlib/RingTheory/LocalRing/LocalRingDimension.lean,Mathlib/RingTheory/LocalRing/RegularLocalRings.lean,Mathlib/RingTheory/LocalRing/RingHom/Basic.lean,lake-manifest.json	6	2	['github-actions', 'mathlib4-merge-conflict-bot']	nobody	153-85039 5 months ago	unknown	unknown
28718	imbrem author:imbrem	feat: class for chosen finite coproducts	Added basic `ChosenFiniteCoproducts` class, and started porting some of the lemmas about `ChosenFiniteProducts` suitably translated --- This, combined with #20182 modified to use chosen finite coproducts and premonoidal categories (#21488), should be enough for me to formalize strong Elgot categories, and hence a lot of categorical iteration theory for my PhD thesis. Re-done from #21603 to deal with changes in #24399 and #24390 Eventually, if we really want to harmonize approaches, we could introduce an `AddMonoidalCategory` struct and do the analogous to #24399 and #24390 for additive monoidal structure, but that seems like a massive overcomplication for now. It would allow formalizing fun things like rig categories, though. - [ ] depends on: #30150	blocked-by-other-PR t-category-theory new-contributor merge-conflict awaiting-author	290/0	Mathlib.lean,Mathlib/CategoryTheory/ChosenFiniteCoproducts.lean	2	9	['YaelDillies', 'github-actions', 'imbrem', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'robin-carlier']	nobody	153-84951 5 months ago	unknown	unknown
26765	KiringYJ author:KiringYJ	feat(MeasureTheory/PiSystem): add π-λ theorem and SetLike instance	Add two small features to `MeasureTheory/PiSystem`: 1. SetLike instance `instance : SetLike (DynkinSystem α) (Set α)` This lets us write `s ⊆ d` and `t ∈ d` for a DynkinSystem `d`, matching usual mathlib style. 2. `DynkinSystem.pi_lambda` lemma Classical π‑λ theorem: if a π‑system `s` is contained in a Dynkin system `d`, every set measurable for `σ(s)` is also in `d`. Currently, mathlib exposes this result only indirectly (e.g. via `generateFrom_eq`). Although logically equivalent, it is not obvious at first glance that those lemmas are the π‑λ theorem. The new lemma states the result in its familiar textbook form, so users can recognise and cite it immediately. Both pieces are under 10 lines, term‑mode only, and do not modify existing APIs. No breaking changes. No dependencies.	awaiting-author t-measure-probability new-contributor	13/0	Mathlib/MeasureTheory/PiSystem.lean	1	14	['EtienneC30', 'KiringYJ', 'dagurtomas', 'github-actions', 'ocfnash']	RemyDegenne assignee:RemyDegenne	153-71347 5 months ago	153-71347 153 days ago	135-34213 135 days
30637	strihanje01 author:strihanje01	feat(Combinatorics/SetFamily/Lindstrom): Lindstrom's theorem for subfamilies with equal unions	add Lindstrom's theorem and its strengthening for equal intersections --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-combinatorics new-contributor	209/0	Mathlib/Combinatorics/SetFamily/Lindstrom.lean	1	2	['github-actions', 'mathlib4-merge-conflict-bot']	b-mehta assignee:b-mehta	151-7096 5 months ago	154-25255 154 days ago	31-45300 31 days
31796	dobronx1325 author:dobronx1325	feat(Data/Real/EReal): add mul_lt_mul_of_pos_left theorem	This PR adds the theorem `EReal.mul_lt_mul_of_pos_left`, which states that for a positive real number `a` and extended reals `b < c`, left multiplication by `a` preserves the strict order: `(a : EReal) * b < (a : EReal) * c`. The theorem complements existing order-preserving properties for addition in `EReal` and extends the algebraic structure for multiplication. The proof uses basic properties of extended reals and order relations. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data new-contributor	23/0	Mathlib/Data/EReal/Operations.lean	1	4	['JovanGerb', 'LLaurance', 'dobronx1325', 'github-actions']	nobody	147-41138 4 months ago	148-11050 148 days ago	6-21252 6 days
32169	saodimao20 author:saodimao20	feat: add convolution_comp_add_right	This PR adds a lemma `convolution_comp_translation_right` showing that convolution commutes with translation on the right operand. Specifically, it proves that for an additive commutative group $G$, the convolution of a function $f$ with a translated function $x \mapsto g(a + x)$ is equal to the convolution of $f$ and $g$ evaluated at $x + a$. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-analysis new-contributor awaiting-author	14/0	Mathlib/Analysis/Convolution.lean	1	3	['github-actions', 'urkud']	nobody	145-27518 4 months ago	145-27518 145 days ago	0-81373 22 hours
32126	nielsvoss author:nielsvoss	feat(Analysis/Normed/Operator): definition of singular values for linear maps	This PR defines a generalization of singular values, the approximation numbers, for continuous linear maps between normed vector spaces. It proves basic lemmas about the approximation numbers and shows that for finite-dimensional vector spaces, the approximation numbers coincide with the standard definition of singular values. See the discussion on Zulip: https://leanprover.zulipchat.com/#narrow/channel/217875-Is-there-code-for-X.3F/topic/Singular.20Value.20Decomposition/with/558914024 Co-authored-by: Arnav Mehta Co-authored-by: Rawad Kansoh --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	WIP t-analysis new-contributor	331/0	Mathlib/Analysis/Normed/Operator/SingularValues.lean	1	2	['github-actions', 'nielsvoss']	nobody	144-65059 4 months ago	unknown	unknown
31898	ntapiam author:ntapiam	feat(LinearAlgebra/TensorAlgebra): implement HopfAlgebra for TensorAlgebra	implementation of the natural Hopf algebra structure on the TensorAlgebra	new-contributor t-ring-theory awaiting-author	253/0	Mathlib.lean,Mathlib/Algebra/FreeAlgebra.lean,Mathlib/LinearAlgebra/TensorAlgebra/Basic.lean,Mathlib/RingTheory/Bialgebra/FreeAlgebra.lean,Mathlib/RingTheory/Bialgebra/TensorAlgebra.lean,Mathlib/RingTheory/HopfAlgebra/TensorAlgebra.lean	6	64	['YaelDillies', 'github-actions', 'kckennylau', 'ntapiam']	nobody	137-85895 4 months ago	150-52708 150 days ago	0-30128 8 hours
30525	515801431 author:515801431	feat(Mathlib/Combinatorics/Enumerative/Polya): Add Polya Counting	This PR introduces basic definitions and results about colorings under permutation group actions. A coloring is defined as a function X → Y, and the permutation group Equiv.Perm X acts on colorings by precomposition: (g • c) x = c (g⁻¹ • x) This formalizes the natural action of relabeling the elements of X. Main definitions MulAction (Equiv.Perm X) (X → Y): The action of the permutation group on colorings via precomposition. coloringEquiv (c₁ c₂ : X → Y) : Prop: Two colorings are equivalent if they lie in the same orbit under this action, i.e. ∃ f : Equiv.Perm X, f • c₁ = c₂. Main results smul_eq_iff_mem_stabilizer: Characterizes when two group actions on the same coloring are equal, showing that g • c = f • c ↔ f⁻¹ * g ∈ stabilizer c. coloringEquiv_equivalence: Proves that coloringEquiv defines an equivalence relation on X → Y. orbit_size_eq_index: Reformulates the orbit–stabilizer theorem in the context of colorings: \|orbit c\| = \|Perm X\| / \|stabilizer c\| Motivation These results provide foundational infrastructure for studying Burnside’s lemma and Pólya’s enumeration theorem in Mathlib, where the enumeration of distinct colorings up to symmetry plays a central role.	t-combinatorics new-contributor awaiting-author merge-conflict	113/0	Mathlib.lean,Mathlib/Combinatorics/Enumerative/Polya.lean	2	8	['IvanRenison', 'alreadydone', 'github-actions', 'mathlib4-merge-conflict-bot']	awainverse assignee:awainverse	137-72657 4 months ago	146-29800 146 days ago	39-39956 39 days
31113	515801431 author:515801431	feat(Mathlib/Combinatorics/Enumerative/Polya.lean): Add additional theorem in `Polya.lean`	--- - [ ] depends on: #30525 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-combinatorics new-contributor blocked-by-other-PR merge-conflict	302/0	Mathlib.lean,Mathlib/Combinatorics/Enumerative/Polya.lean	2	4	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	b-mehta assignee:b-mehta	137-72533 4 months ago	147-8559 147 days ago	16-74719 16 days
24441	MrSumato author:MrSumato	feat(Data/List): add Lyndon-Schutzenberger theorem on list commutativity	Add Lyndon-Schutzenberger theorem on list commutativity. Included definition for List.repeatSelf that returns list repeated n times. --- This is my first mathlib PR, so any comments are highly appreciated. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict awaiting-author t-data new-contributor	129/1	Mathlib.lean,Mathlib/Data/List/Commutativity.lean,Mathlib/Data/List/Defs.lean,Mathlib/Data/List/Lemmas.lean	4	38	['MrSumato', 'github-actions', 'grunweg', 'madvorak', 'mathlib4-merge-conflict-bot', 'plp127']	grunweg assignee:grunweg	137-68135 4 months ago	unknown	unknown
31147	daefigueroa author:daefigueroa	feat(Dynamics): point transitive monoid actions and transitive points	We define point transitivity for a monoid action on a topological space and define the set of transitive points. We add some basic lemmas and implications between topological transitivity and point transitivity. --- - [x] depends on: #28001 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-dynamics new-contributor awaiting-author	114/6	Mathlib/Dynamics/Transitive.lean	1	6	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'sgouezel']	sgouezel assignee:sgouezel	135-6968 4 months ago	135-6968 135 days ago	18-34491 18 days
31987	saodimao20 author:saodimao20	feat: add monotonicity and relation lemmas for mgf and cgf	Add two lemmas about moment-generating and cumulant-generating functions: - `mgf_mono_in_t_of_nonneg`: For nonnegative random variables, the mgf is monotone in the parameter `t` - `cgf_zero_of_mgf_one`: The cgf equals zero iff the mgf equals one These lemmas are useful for studying properties of mgf and cgf in probability theory. Contributed by sequential-intelligence-lab(SIL), University of Virginia --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-measure-probability new-contributor awaiting-author	21/0	Mathlib/Probability/Moments/Basic.lean	1	5	['DavidLedvinka', 'github-actions']	RemyDegenne assignee:RemyDegenne	128-85474 4 months ago	128-85474 128 days ago	21-30654 21 days
32938	0xTerencePrime author:0xTerencePrime	feat(Order/LocallyFinite): prove DenselyOrdered and LocallyFiniteOrder are incompatible	## Summary This PR proves that a nontrivial densely ordered linear order cannot be locally finite. ## Main results * `not_locallyFiniteOrder`: A densely ordered locally finite linear order must be subsingleton. * `not_locallyFiniteOrder_of_nontrivial`: The main theorem - incompatibility of the two properties. Note: This implementation imports `Mathlib.Order.Interval.Set.Infinite` to reuse the existing `Set.Icc_infinite` theorem, ensuring standard library consistency. ## Mathematical content The key insight is that in a densely ordered type, we can always find a new element between any two distinct elements. This means any nontrivial interval contains infinitely many elements. However, `LocallyFiniteOrder` requires intervals to be finite. This contradiction implies that such a type cannot exist (unless it is trivial). ## Motivation This resolves a TODO mentioned in #7987 (Data/Finset/LocallyFinite entry). ## Verification - [x] `lake build Mathlib.Order.LocallyFinite.Basic` passes - [x] `lake exe runLinter Mathlib.Order.LocallyFinite.Basic` passes	t-order new-contributor awaiting-author	28/0	Mathlib/Order/Interval/Finset/Basic.lean	1	10	['0xTerencePrime', 'CoolRmal', 'github-actions', 'jcommelin', 'plp127']	nobody	124-22476 4 months ago	124-22516 124 days ago	2-83075 2 days
32698	farruhx author:farruhx	feat(List): add aesop / simp annotations to selected lemmas for improved automation	This PR adds `@[aesop safe]` and `@[simp]` annotations to a set of List lemmas whose proofs are routine and benefit from standardized automation. No statements or definitions are changed; only proof annotations are added. The lemmas updated in this PR are: * `or_exists_of_exists_mem_cons` * `append_subset_of_subset_of_subset` * `map_subset_iff` * `append_eq_has_append` * `append_right_injective` * `append_left_injective` * `reverse_surjective` * `reverse_bijective` * `mem_getLast?_append_of_mem_getLast?` * `mem_dropLast_of_mem_of_ne_getLast` * `idxOf_eq_length_iff` * `idxOf_append_of_mem` * `length_eraseP_add_one` The goal is to make these commonly used lemmas easier for `aesop`-based automation to resolve, while avoiding any interference with simp-normal-form lemmas or canonical rewrite rules. There are no API changes and no new theorems—only improved automation behavior.	t-data new-contributor awaiting-author	18/1	Mathlib/Data/List/Basic.lean	1	8	['artie2000', 'euprunin', 'farruhx', 'github-actions']	pechersky assignee:pechersky	123-57245 4 months ago	123-57245 123 days ago	7-30937 7 days
27817	zhuyizheng author:zhuyizheng	feat: add IMO2025P1	Add a solution to IMO2025P1, the original problem statement from https://github.com/jsm28/IMOLean --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	IMO awaiting-author new-contributor merge-conflict	1310/0	Archive.lean,Archive/Imo/Imo2025Q1.lean	2	9	['github-actions', 'kim-em', 'mathlib4-merge-conflict-bot', 'zhuyizheng']	dwrensha assignee:dwrensha	123-3042 4 months ago	182-54010 182 days ago	54-69322 54 days
26923	oliver-butterley author:oliver-butterley	feat(Dynamics/BirkhoffSum): add the pointwise ergodic theorem (Birkhoff's)	The Pointwise Ergodic Theorem, also known as Birkhoff's Ergodic Theorem. Co-authored-by: Lua Viana Reis - [x] depends on: #26074 - [x] depends on: #26807 - [x] depends on: #26810 - [x] depends on: #26840 - [x] depends on: #26842 - [x] depends on: #26848 - [x] depends on: #26851 - [x] depends on: #26852 - [x] depends on: #26853 - [x] depends on: #27008 - [x] depends on: #28901 Zulip: [PR thread](https://leanprover.zulipchat.com/#narrow/channel/144837-PR-reviews/topic/.2326923.20The.20pointwise.20ergodic.20theorem.20.28Birkhoff's.29/with/527835158) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-dynamics new-contributor awaiting-author	398/0	Mathlib.lean,Mathlib/Dynamics/BirkhoffSum/Pointwise.lean	2	31	['D-Thomine', 'github-actions', 'leanprover-community-bot-assistant', 'lua-vr', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'sgouezel', 'urkud']	sgouezel assignee:sgouezel	121-25465 4 months ago	126-69783 126 days ago	98-44290 98 days
33218	Blackfeather007 author:Blackfeather007	feat(Algebra): Define the associated graded ring to filtered ring	Define the associated graded ring to a filtered ring. --- - [ ] depends on: #33217 migrated from https://github.com/leanprover-community/mathlib4/pull/26858	t-ring-theory new-contributor blocked-by-other-PR	450/0	Mathlib.lean,Mathlib/RingTheory/FilteredAlgebra/AssociatedGraded.lean	2	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	120-35707 3 months ago	unknown	unknown
33219	Blackfeather007 author:Blackfeather007	feat(Algebra): Define associated graded algebra	Define the associated graded algebra of a filtered algebra, constructed from a special case of associated graded ring. --- - [ ] depends on: #33218 migrated from #26859	t-ring-theory new-contributor blocked-by-other-PR	563/0	Mathlib.lean,Mathlib/RingTheory/FilteredAlgebra/AssociatedGraded.lean	2	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	120-35599 3 months ago	unknown	unknown
33220	Blackfeather007 author:Blackfeather007	feat(Algebra): Define associated graded module	Define the associated graded module to a filtered module. --- - [ ] depends on: #33218 migrated from #26860	t-ring-theory new-contributor blocked-by-other-PR	669/0	Mathlib.lean,Mathlib/RingTheory/FilteredAlgebra/AssociatedGraded.lean	2	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	120-35515 3 months ago	unknown	unknown
33227	Blackfeather007 author:Blackfeather007	feat(Algebra): exact of associated graded exact	We proved that a chain complex is exact if its associated graded complex is exact. Co-authored-by: Huanyu Zheng @Yu-Misaka [suzuka@misaka-yu.com](mailto:suzuka@misaka-yu.com) Co-authored-by: Yi Yuan @yuanyi-350 [kysyy1@126.com](mailto:kysyy1@126.com) Co-authored-by: Weichen Jiao @AlbertJ-314 [albertjiao314@gmail.com](mailto:albertjiao314@gmail.com) --- - [ ] depends on: #33226 migrated from #26869	t-ring-theory new-contributor blocked-by-other-PR	728/0	Mathlib.lean,Mathlib/RingTheory/FilteredAlgebra/AssociatedGraded.lean,Mathlib/RingTheory/FilteredAlgebra/Exactness.lean,Mathlib/RingTheory/FilteredAlgebra/FilteredHom.lean	4	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	120-33187 3 months ago	120-33188 120 days ago	0-206 3 minutes
33226	Blackfeather007 author:Blackfeather007	feat(Algebra): associated graded exact of exact and strict	In this file, we define the concept of exhaustive filtrations. We also prove a AssociatedGradedRingHom sequence is exact iff each GradedPieceHom is exact. And when a sequence is strict exact, the corresponding AssociatedGradedRingHom sequence is also exact. Co-authored-by: Huanyu Zheng @Yu-Misaka [suzuka@misaka-yu.com](mailto:suzuka@misaka-yu.com) Co-authored-by: Yi Yuan @yuanyi-350 [kysyy1@126.com](mailto:kysyy1@126.com) Co-authored-by: Weichen Jiao @AlbertJ-314 [albertjiao314@gmail.com](mailto:albertjiao314@gmail.com) --- - [ ] depends on: #33222 migrated from #26868	t-ring-theory new-contributor blocked-by-other-PR	529/0	Mathlib.lean,Mathlib/RingTheory/FilteredAlgebra/AssociatedGraded.lean,Mathlib/RingTheory/FilteredAlgebra/Exactness.lean,Mathlib/RingTheory/FilteredAlgebra/FilteredHom.lean	4	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	120-33185 3 months ago	120-33186 120 days ago	0-415 6 minutes
33225	Blackfeather007 author:Blackfeather007	feat(Algebra): filtered module hom	In this PR we defined the filtered semi-linear map for filtered module and the associated graded module hom. --- - [ ] depends on: #33220 - [ ] depends on: #33223 migrated from #26867	t-ring-theory new-contributor blocked-by-other-PR	1205/0	Mathlib.lean,Mathlib/RingTheory/FilteredAlgebra/AssociatedGraded.lean,Mathlib/RingTheory/FilteredAlgebra/FilteredHom.lean	3	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	120-33184 3 months ago	unknown	unknown
33224	Blackfeather007 author:Blackfeather007	feat(Algebra): define filtered alghom	In this PR, we define the filtered algebra homomorphisms on algebras and prove some basic properties of them. --- - [ ] depends on: #33219 - [ ] depends on: #33223 migrated from #26863	t-ring-theory new-contributor blocked-by-other-PR	1055/0	Mathlib.lean,Mathlib/RingTheory/FilteredAlgebra/AssociatedGraded.lean,Mathlib/RingTheory/FilteredAlgebra/FilteredHom.lean	3	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	120-33182 3 months ago	120-33183 120 days ago	0-978 16 minutes
33223	Blackfeather007 author:Blackfeather007	feat(Algebra): define filtered ring homomorphism	In this PR, we define the filtered ring morphisms on rings and prove some basic properties of them. Co-authored-by: Huanyu Zheng @Yu-Misaka [suzuka@misaka-yu.com](mailto:suzuka@misaka-yu.com) Co-authored-by: Yi Yuan @yuanyi-350 [kysyy1@126.com](mailto:kysyy1@126.com) Co-authored-by: Weichen Jiao @AlbertJ-314 [albertjiao314@gmail.com](mailto:albertjiao314@gmail.com) --- - [ ] depends on: #33218 - [ ] depends on: #33222 migrated from #26862	t-ring-theory new-contributor blocked-by-other-PR	824/0	Mathlib.lean,Mathlib/RingTheory/FilteredAlgebra/AssociatedGraded.lean,Mathlib/RingTheory/FilteredAlgebra/FilteredHom.lean	3	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	120-33179 3 months ago	120-33182 120 days ago	0-1162 19 minutes
33222	Blackfeather007 author:Blackfeather007	feat(Algebra): define filtered add group hom	In this file we define filtered hom and the corresponding associated graded hom for abelian groups. Co-authored-by: Huanyu Zheng @Yu-Misaka [suzuka@misaka-yu.com](mailto:suzuka@misaka-yu.com) Co-authored-by: Yi Yuan @yuanyi-350 [kysyy1@126.com](mailto:kysyy1@126.com) Co-authored-by: Weichen Jiao @AlbertJ-314 [albertjiao314@gmail.com](mailto:albertjiao314@gmail.com) --- - [ ] depends on: #33217 migrated from #26861	new-contributor t-ring-theory blocked-by-other-PR	368/0	Mathlib.lean,Mathlib/RingTheory/FilteredAlgebra/AssociatedGraded.lean,Mathlib/RingTheory/FilteredAlgebra/FilteredHom.lean	3	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	120-33178 3 months ago	120-33179 120 days ago	0-1375 22 minutes
33178	gw90 author:gw90	feat(Analysis/CStarAlgebra/Spectrum): Adding lemmas that the CStarAlgebra norm equals the square root of the spectral radius of star a * a	Adds lemmas that the \|\|a\|\|^2_A=sqrt(spectralRadius C (star a * a)). I think it would be helpful to have these lemmas available in Mathlib. It'll help with some of the other things I'm working on. Feel free to move them to a different file or rename them as you see fit.	new-contributor t-analysis awaiting-author	24/0	Mathlib/Analysis/CStarAlgebra/Spectrum.lean	1	15	['github-actions', 'gw90', 'themathqueen', 'vihdzp']	nobody	119-71446 3 months ago	121-47065 121 days ago	0-14281 3 hours
32264	jjtowery author:jjtowery	feat(Bicategory): add lax slice bicategory	--- In this PR, I define the lax slice bicategory for a lax functor over an object. I also give the change of slice strict pseudofunctor. These are from Section 7.1 of Johnson & Yau and are essential for their Whitehead theorem for bicategories (lax functor biequivalence iff essentially surjective, essentially full, and fully faithful), which I'd like to prove at some point. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-category-theory new-contributor awaiting-author	527/0	Mathlib.lean,Mathlib/CategoryTheory/Bicategory/LaxSlice.lean	2	12	['dagurtomas', 'github-actions', 'jjtowery', 'robin-carlier']	dagurtomas assignee:dagurtomas	116-61664 3 months ago	139-65121 139 days ago	3-46291 3 days
32960	dleijnse author:dleijnse	feat(FieldTheory): adjoin pth roots	For a field `k` of exponential characteristic `p` and a subset `S` of `k`, we define the extension of `k` obtained by adjoining all `p`-th roots of elements of `S`. We prove that this is a purely inseparable extension, and provide some basic API. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra new-contributor awaiting-author label:t-algebra$	131/0	Mathlib.lean,Mathlib/FieldTheory/PurelyInseparable/AdjoinPthRoots.lean	2	13	['artie2000', 'chrisflav', 'dleijnse', 'erdOne', 'github-actions', 'leanprover-radar']	erdOne assignee:erdOne	115-78316 3 months ago	115-78316 115 days ago	10-11880 10 days
33163	Aaron1011 author:Aaron1011	feat: prove subgroup of (M -> Z) is finitely generated	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-ring-theory new-contributor awaiting-author	5/0	Mathlib/RingTheory/DedekindDomain/Dvr.lean	1	2	['erdOne', 'github-actions']	alreadydone assignee:alreadydone	115-71266 3 months ago	115-71266 115 days ago	5-78603 5 days
33133	0xTerencePrime author:0xTerencePrime	feat(Algebra/Group/Center): add Decidable (IsMulCentral a) instance	This PR adds a `Decidable` instance for `IsMulCentral a`. ### Summary The structure `IsMulCentral` was missing a `Decidable` instance. This PR provides the instance by leveraging `isMulCentral_iff`, enabling decidability for both multiplicative and additive (via `to_additive`) structures. ### Verification - `lake build Mathlib.Algebra.Group.Center` passed. - `lake exe runLinter Mathlib.Algebra.Group.Center` passed.	t-algebra new-contributor awaiting-author label:t-algebra$	7/0	Mathlib/Algebra/Group/Center.lean	1	3	['github-actions', 'robin-carlier']	ocfnash assignee:ocfnash	110-13057 3 months ago	110-13057 110 days ago	12-58151 12 days
33502	MrQubo author:MrQubo	fix(Tactic/ProxyType): Pass params explicitly in proxy_equiv% implementation	Fix [#mathlib4 > `deriving Fintype` with Prop](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/.60deriving.20Fintype.60.20with.20Prop/with/566118621) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-meta WIP	12/2	Mathlib/Tactic/ProxyType.lean,MathlibTest/DeriveFintype.lean	2	7	['MrQubo', 'github-actions', 'kmill']	kmill assignee:kmill	108-66381 3 months ago	108-66382 108 days ago	0-57325 15 hours
17176	arulandu author:arulandu	feat: integrals and integrability with .re	Lemmas for swapping order of .re and integration/integrability. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict awaiting-author new-contributor t-measure-probability please-adopt	49/0	Mathlib/MeasureTheory/Function/L1Space.lean,Mathlib/MeasureTheory/Integral/IntegrableOn.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral.lean,Mathlib/MeasureTheory/Integral/SetIntegral.lean	4	32	['EtienneC30', 'arulandu', 'github-actions', 'loefflerd']	nobody	106-69379 3 months ago	unknown	unknown
33756	dleijnse author:dleijnse	feat(FieldTheory): root of polynomial with p power coefficients	This PR proves the results in https://stacks.math.columbia.edu/tag/031V, which gives a criterion for a root of a polynomial over a field `k` of characteristic `p` to be a `p`-th power. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra new-contributor label:t-algebra$	88/0	Mathlib.lean,Mathlib/FieldTheory/PthPowerCoeffPoly.lean	2	1	['github-actions']	nobody	104-1479 3 months ago	unknown	unknown
33299	kingiler author:kingiler	feat: Add decidable membership for Interval	Implemented membership and corresponding decidable instance for `Interval`. Related [#mathlib4 > Proposal: Add decidable membership for Interval](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Proposal.3A.20Add.20decidable.20membership.20for.20Interval/with/565438009). --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-author new-contributor t-order	16/1	Mathlib/Order/Interval/Basic.lean	1	5	['Vierkantor', 'eric-wieser', 'github-actions', 'kingiler']	Vierkantor assignee:Vierkantor	103-79685 3 months ago	103-79685 103 days ago	13-40294 13 days
32880	0xTerencePrime author:0xTerencePrime	feat(Analysis/Asymptotics): define subpolynomial growth	## Main definitions * `Asymptotics.IsSubpolynomial l f g`: A function `f` has subpolynomial growth with respect to `g` along filter `l` if `f = O(1 + ‖g‖^k)` for some natural `k`. ## Main results * `IsSubpolynomial.const`: Constant functions have subpolynomial growth * `IsSubpolynomial.id`: Identity has subpolynomial growth * `IsSubpolynomial.add`: Closure under addition * `IsSubpolynomial.neg`: Closure under negation * `IsSubpolynomial.sub`: Closure under subtraction * `IsSubpolynomial.mul`: Closure under multiplication * `IsSubpolynomial.pow`: Closure under powers * `isSubpolynomial_iff_one_add`: Equivalence with `(1 + ‖g‖)^k` formulation * `IsSubpolynomial.uniform`: Uniform bounds for finite families ## Implementation notes The definition uses `1 + ‖g‖^k` rather than `(1 + ‖g‖)^k` as the primary form, with the equivalence established in `isSubpolynomial_iff_one_add`. Four private auxiliary lemmas handle the key inequalities needed for closure proofs. Closes #32658	awaiting-author t-analysis new-contributor	185/0	Mathlib.lean,Mathlib/Analysis/Asymptotics/Subpolynomial.lean	2	28	['0xTerencePrime', 'ADedecker', 'github-actions', 'j-loreaux']	ADedecker assignee:ADedecker	99-72453 3 months ago	100-53911 100 days ago	22-12319 22 days
33948	anivegesana author:anivegesana	feat(Analysis/Normed/Algebra): matrix exponential of nilpotent matrix	Where the matrix exponential and nilpotent elements are defined, both the matrix exponential and the nilpotent element exponential. I had to add a different theorem for normed space exponential and the matrix exponential since the right instances wouldn't be synthesized. Help with golfing would be appreciated. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-analysis	34/0	Mathlib/Analysis/Normed/Algebra/Exponential.lean,Mathlib/Analysis/Normed/Algebra/MatrixExponential.lean	2	1	['github-actions']	nobody	98-37038 3 months ago	unknown	unknown
30391	rudynicolop author:rudynicolop	feat(Data/List): list splitting definitions and lemmas	This PR continues the work from #24395. Original PR: https://github.com/leanprover-community/mathlib4/pull/24395	t-data new-contributor awaiting-author	108/2	Mathlib/Data/List/Perm/Lattice.lean,Mathlib/Data/List/TakeDrop.lean	2	50	['BoltonBailey', 'IlPreteRosso', 'TwoFX', 'Vierkantor', 'github-actions', 'kckennylau', 'mathlib4-merge-conflict-bot', 'rudynicolop']	TwoFX assignee:TwoFX	96-4384 3 months ago	96-12906 96 days ago	91-66874 91 days
29282	Jlh18 author:Jlh18	feat(CategoryTheory): HasColimits instance on Grpd	Show that the category of groupoids has all small colimits, as a coreflective subcategory of `Cat`, which has all small colimits. The right adjoint of the forgetful functor is the core functor `CategoryTheory.Core.functor`. - [ ] depends on: #29283 [Core of a category as a functor] --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict blocked-by-other-PR new-contributor t-category-theory	140/4	Mathlib.lean,Mathlib/AlgebraicTopology/FundamentalGroupoid/InducedMaps.lean,Mathlib/CategoryTheory/Category/Grpd.lean,Mathlib/CategoryTheory/Core.lean,Mathlib/CategoryTheory/Groupoid/Grpd/Colimit.lean,Mathlib/CategoryTheory/Groupoid/Grpd/Core.lean	6	3	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	94-14464 3 months ago	unknown	unknown
33478	anishrajeev author:anishrajeev	feat(ModelTheory): define a subset of the topology over complete types	Define a subset of the Stone Space over a language expanded with countably many constants. Define the proposition to indicate if a language is countable. The subset's density and openness is a future goal to prove (have a branch where it is almost finished), in pursuit of formalizing the proof of the Omitting Types Theorem via properties of Baire spaces. - [ ] depends on: #32215 - [ ] depends on: #32546	t-logic blocked-by-other-PR merge-conflict new-contributor	160/1	Mathlib.lean,Mathlib/ModelTheory/Topology/Types.lean,Mathlib/ModelTheory/Types.lean,Mathlib/Tactic/Linter/DirectoryDependency.lean	4	8	['NoneMore', 'anishrajeev', 'github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'tb65536']	nobody	91-80249 3 months ago	100-7673 100 days ago	10-30503 10 days
34141	gululu996-ui author:gululu996-ui	feat(Combinatorics/SimpleGraph/Acyclic): finite trees have at least two degree-one vertices	Add a lemma showing that a finite tree with at least two vertices has at least two vertices of degree 1. - Introduce a helper lemma `SimpleGraph.Connected.one_le_degree` for connected graphs on a nontrivial finite type. - Prove the leaf-count lower bound via the degree-sum identity and a counting argument. ---	awaiting-author new-contributor t-combinatorics	72/2	Mathlib/Combinatorics/SimpleGraph/Acyclic.lean	1	9	['IvanRenison', 'SnirBroshi', 'github-actions', 'vlad902']	nobody	89-84007 2 months ago	91-65443 91 days ago	1-21793 1 day
34129	idontgetoutmuch author:idontgetoutmuch	feat: define Ehresmann connections	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-author t-differential-geometry new-contributor	90/0	Mathlib.lean,Mathlib/Geometry/Manifold/EhresmannConnection.lean	2	5	['github-actions', 'grunweg', 'idontgetoutmuch', 'metakunt']	nobody	89-19157 2 months ago	unknown	unknown
29953	slashbade author:slashbade	feat: add reap for experiment	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor	40/3	Cache/IO.lean,Mathlib/Tactic/Common.lean,Mathlib/Tactic/Linter/DirectoryDependency.lean,lake-manifest.json,lakefile.lean	5	3	['github-actions', 'mathlib4-merge-conflict-bot']	nobody	84-76532 2 months ago	unknown	unknown
31377	CoolRmal author:CoolRmal	feat: a series of smooth functions that converges (locally) uniformly is smooth	The main theorem is the proof that an infinite sum of $C^n$ functions on a one-dimensional domain which converges locally uniformly is $C^n$ and related results. This should be compared with [contDiff_tsum](https://leanprover-community.github.io/mathlib4_docs/Mathlib/Analysis/Calculus/SmoothSeries.html#contDiff_tsum) where the same result is proved for functions on an arbitrary domain but with a slightly stronger convergence assumption. The main motivation for this PR is the [#mathlib4 > Tychonov's Counterexample for the Heat Equation](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Tychonov's.20Counterexample.20for.20the.20Heat.20Equation/with/547367912). --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology new-contributor awaiting-author merge-conflict	110/18	Mathlib/Analysis/Calculus/SmoothSeries.lean,Mathlib/Analysis/SpecialFunctions/Trigonometric/Cotangent.lean,Mathlib/NumberTheory/ModularForms/EisensteinSeries/QExpansion.lean,Mathlib/Topology/Algebra/InfiniteSum/TsumUniformlyOn.lean,Mathlib/Topology/Algebra/InfiniteSum/UniformOn.lean	5	20	['CoolRmal', 'github-actions', 'mathlib4-merge-conflict-bot', 'ocfnash', 'sgouezel']	ocfnash assignee:ocfnash	83-66105 2 months ago	144-83070 144 days ago	8-9680 8 days
33031	chiyunhsu author:chiyunhsu	feat(Combinatorics/Enumerative/Partition): add combinatorial proof of Euler's partition theorem	The new file EulerComb.lean contains the combinatorial proof of Euler's partition theorem. The analytic proof of the theorem and its generalization of Glaisher's Theorem has already been formalized in [Glaisher.lean](https://github.com/leanprover-community/mathlib4/blob/master/Mathlib/Combinatorics/Enumerative/Partition/Glaisher.lean). The generalization of the combinatorial proof from this file to Glaisher's Theorem is within reach. --- Zulip discussion: [#mathlib4 > Glaisher’s Bijection on integer partitions](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Glaisher.E2.80.99s.20Bijection.20on.20integer.20partitions/with/570808111) [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-combinatorics new-contributor awaiting-zulip	531/0	Mathlib.lean,Mathlib/Combinatorics/Enumerative/Partition/EulerComb.lean	2	5	['chiyunhsu', 'github-actions', 'tb65536', 'vihdzp']	b-mehta assignee:b-mehta	83-3226 2 months ago	83-3226 83 days ago	42-19879 42 days
34130	FlAmmmmING author:FlAmmmmING	feat(Combinatorics/SimpleGraph/Acyclic): Add new theorem `isTree_iff_uniqueShortest_path`	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-author t-combinatorics new-contributor	28/1	Mathlib/Combinatorics/SimpleGraph/Acyclic.lean	1	9	['IvanRenison', 'github-actions', 'metakunt', 'vlad902']	nobody	82-25633 2 months ago	91-9648 91 days ago	2-3674 2 days
32609	PrParadoxy author:PrParadoxy	feat(LinearAlgebra/PiTensorProduct): Relation between nested tensor products and tensor products indexed by dependent sums	Product tensors in `⨂ j : (Σ i, β i), s j.fst j.snd` can be mapped to product tensors in `⨂ i, ⨂ b : β i, s i b`. If the outer index type is finite, the two types are equivalent. This allows the definition of endomorphisms on PiTensorProducts by specifying them on disjoint subsets of the index set. Such constructions are common e.g. in quantum circuits, quantum cellular automata, and renormalization procedures. --- WIP. This PR contains two "requests for comments". Essentially: * Is a single complex-to-define linear equivalence preferable over several less complex ones, which might however be of limited interest by themselves? * Which trade-offs are appropriate to make things computable? - [ ] depends on: #32608 - [x] depends on: #32600 - [x] depends on: #32598 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor blocked-by-other-PR merge-conflict t-algebra label:t-algebra$	683/0	Mathlib.lean,Mathlib/Data/Sigma/Basic.lean,Mathlib/LinearAlgebra/Multilinear/Basic.lean,Mathlib/LinearAlgebra/PiTensorProduct/Nested.lean,Mathlib/LinearAlgebra/PiTensorProduct/Set.lean	5	5	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	80-63438 2 months ago	134-63876 134 days ago	0-614 10 minutes
30260	imbrem author:imbrem	feat(CategoryTheory/Monoidal): added CocartesianMonoidalCategory	As discussed in #21603 and #28718; this implements chosen finite coproducts on top of `AddMonoidalCategory` as defined in #30150 --- - [ ] depends on: #30150 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict blocked-by-other-PR large-import new-contributor t-category-theory	839/125	Mathlib.lean,Mathlib/CategoryTheory/Monoidal/Category.lean,Mathlib/CategoryTheory/Monoidal/Cocartesian/Basic.lean,Mathlib/CategoryTheory/Monoidal/Discrete.lean,Mathlib/Tactic/ToAdditive/GuessName.lean	5	4	['github-actions', 'imbrem', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	80-15869 2 months ago	unknown	unknown
30258	imbrem author:imbrem	feat(CategoryTheory/Monoidal): to_additive for proofs using `monoidal`	Building on #30150, this allows us to use `@[to_additive]` on proofs containing `monoidal`, by tagging the lemmas `monoidal` outputs with `@[to_additive]` as appropriate. Testing on my branch [`additive-monoidal-coherence`](https://github.com/imbrem/mathlib4/tree/additive-monoidal-coherence) shows that this works. It is still future work to have either the `monoidal` tactic or a new `add_monoidal` tactic work for `AddMonoidalCategory` instances directly. --- - [ ] depends on: #30150 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict blocked-by-other-PR large-import new-contributor t-category-theory	524/140	Mathlib/CategoryTheory/Monoidal/Category.lean,Mathlib/CategoryTheory/Monoidal/Discrete.lean,Mathlib/Tactic/CategoryTheory/Monoidal/Normalize.lean,Mathlib/Tactic/CategoryTheory/Monoidal/PureCoherence.lean,Mathlib/Tactic/CategoryTheory/MonoidalComp.lean,Mathlib/Tactic/ToAdditive/GuessName.lean	6	3	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	80-15862 2 months ago	unknown	unknown
32742	LTolDe author:LTolDe	feat(MeasureTheory/Constructions/Polish/Basic): add class SuslinSpace	add new class `SuslinSpace` for a topological space that is an analytic set in itself This will be useful to prove the Effros Theorem, see [zulip thread](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Effros.20Theorem/with/558712441). --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor awaiting-zulip t-measure-probability	4/0	Mathlib/MeasureTheory/Constructions/Polish/Basic.lean	1	9	['ADedecker', 'LTolDe', 'dupuisf', 'github-actions', 'jcommelin']	PatrickMassot assignee:PatrickMassot	80-15636 2 months ago	105-86168 105 days ago	0-246 4 minutes
30121	idontgetoutmuch author:idontgetoutmuch	feat(Mathlib/Geometry/Manifold): principal fiber bundle core	A structure capturing what it means to be a principal fibre bundle. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-author t-differential-geometry new-contributor	227/0	Mathlib.lean,Mathlib/Geometry/Manifold/PrincipalFiberBundle/PrincipalGBundle.lean	2	8	['github-actions', 'grunweg', 'idontgetoutmuch', 'mathlib4-merge-conflict-bot']	hrmacbeth assignee:hrmacbeth	80-7577 2 months ago	176-85423 176 days ago	24-63585 24 days
31102	JOSHCLUNE author:JOSHCLUNE	feat: require LeanHammer	Experimenting with adding LeanHammer as a mathlib dependency --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict new-contributor t-meta	61/4	Mathlib/Tactic/Common.lean,Mathlib/Tactic/Linter/DirectoryDependency.lean,MathlibTest/Hammer.lean,lake-manifest.json,lakefile.lean	5	2	['github-actions', 'mathlib4-merge-conflict-bot']	nobody	80-6344 2 months ago	unknown	unknown
33431	gululu996-ui author:gululu996-ui	feat(Combinatorics/SimpleGraph/Bipartite): characterize bipartite simple graphs by even cycles	Add the classical characterization of bipartite simple graphs: a simple graph is bipartite if and only if every cycle has even length. Previously, mathlib has the definition of `IsBipartite` for `SimpleGraph` and various lemmas about bipartite graphs, but it does not provide this equivalence in a single theorem, so users have to reprove or reassemble it from existing results. Prove the forward direction by showing a 2-coloring alternates along any walk, so every cycle must have even length. Prove the converse by showing that if an odd cycle exists then no bipartition is possible, hence if all cycles are even the graph admits a bipartition.	new-contributor t-combinatorics awaiting-author	186/1	Mathlib/Combinatorics/SimpleGraph/Bipartite.lean	1	5	['NickAdfor', 'github-actions', 'jcommelin']	kmill assignee:kmill	80-6076 2 months ago	82-6973 82 days ago	26-95 26 days
34291	YellPika author:YellPika	feat(Data): a monad for partial computations	This is the code corresponding to [mathlib4 > A monad for partial computations](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/A.20monad.20for.20partial.20computations/with/569619800). Not currently intended to be merged. This PR depends on #33941. The only changes relevant to this discussion are in `OmegaPart.lean`, `OmegaProp.lean`, and `Quot.lean`. # Original Message Inspired by @Aaron Liu's comments in #mathlib4>deprecate Mathlib.Data.Nat.PartENat?@538009243 and #Is there code for X?>Divergence monad@538020049 I made an attempt at constructing a monad for partial computations with a computable `OmegaCompletePartialOrder` instance (neither `Option` nor `Part` support this use case). My solution consists of three parts. A computable version of `Quotient.choice`. As mentioned in #lean4>Quot.lift for dependent products@467436416 , the "obvious" computational interpretation of `Quotient.choice : (∀i:I, @Quotient (A i) …) → @Quotient (∀i:I, A i)` is not sound. However, we _can_ provide a sound computational interpretation when we restrict `I` to `ℕ`: ```lean unsafe def Quotient.countableChoice_impl {α : Nat → Type} {S : ∀ i, Setoid (α i)} (f : ∀ i, Quotient (S i)) : @Quotient (∀ i, α i) (by infer_instance) := Quotient.lift₂ (fun z s ↦ ⟦fun \| .zero => z \| .succ n => s n⟧) (fun z₁ s₁ z₂ s₂ h₁ h₂ ↦ by apply sound rintro ⟨_\|n⟩ · apply h₁ · apply h₂) (f 0) (countableChoice_impl (fun n ↦ f n.succ)) @[implemented_by Quotient.countableChoice_impl] def Quotient.countableChoice {α : Nat → Type} {S : ∀ i, Setoid (α i)} (f : ∀ i, Quotient (S i)) : @Quotient (∀ i, α i) (by infer_instance) := Quotient.choice f ``` My justification for the soundness of this implementation comes from the fact that only uses existing (sound and computable) functions + general recursion. The implementation is found [here](https://github.com/YellPika/mathlib4/blob/99d38f164a97c7aa225283ef6016f0279419a994/Mathlib/Data/Quot.lean#L430) (it uses `unquot` instead of recursion for performance reasons, but should be equivalent). A type of semi-computable propositions. Next, I define a type of semi-computable propositions `ΩProp` as a quotient of the type of boolean sequences `(ℕ → Bool) / ≈`, where `p ≈ q ≝ (∃n, p n) ↔ (∃n, q n)`. A sequence is interpreted as "true" if at least one element in the sequence is `true`, and the quotient relation ensures that we cannot observe the difference between different "true" sequences. The `ΩProp` type has a (computable) `OmegaCompletePartialOrder`, and `Quotient.countableChoice` is used in the implementation of `ωSup`. The implementation of this type is [here](https://github.com/YellPika/mathlib4/blob/quot-choice-compute/Mathlib/Data/OmegaProp.lean). A type of semi-computable computations. Finally, I define the type `ΩPart A` of semi-computable computations returning a value of type `A`. The definition of `ΩPart` is the same as `Part` with `ΩProp` swapped for `Prop`. Again, `ΩPart A` has a (computable) `OmegaCompletePartialOrder` instance. The implementation can be found [here](https://github.com/YellPika/mathlib4/blob/quot-choice-compute/Mathlib/Data/OmegaPart.lean). This was mainly just a fun experiment and the code is not ready to be (or perhaps should not be) put in mathlib. I thought I should post it here to see if 1) there is any interest or 2) an implementation already exists that has escaped my notice.	new-contributor large-import merge-conflict	1157/40	Mathlib/Data/OmegaPart.lean,Mathlib/Data/OmegaProp.lean,Mathlib/Data/Quot.lean,Mathlib/Order/OmegaCompletePartialOrder.lean,Mathlib/Order/ScottContinuity.lean	5	2	['github-actions', 'mathlib-merge-conflicts']	nobody	77-70997 2 months ago	unknown	unknown
34053	christian-oudard author:christian-oudard	feat: Add error function (erf) and complementary error function (erfc)	## Summary I was doing some finance math and needed the Error Function, so I thought I'd contribute it. ### Main definitions * `Real.erf`: The error function, defined as `(2/√π) ∫₀ˣ e^(-t²) dt` * `Real.erfc`: The complementary error function, defined as `1 - erf x` ### Main results * `Real.erf_zero`: `erf 0 = 0` * `Real.erf_neg`: `erf` is an odd function: `erf (-x) = -erf x` * `Real.erf_tendsto_one`: `erf x → 1` as `x → ∞` * `Real.erf_tendsto_neg_one`: `erf x → -1` as `x → -∞` * `Real.erf_le_one`: `erf x ≤ 1` for all `x` * `Real.neg_one_le_erf`: `-1 ≤ erf x` for all `x` * `Real.deriv_erf`: `deriv erf x = (2/√π) * exp(-x²)` * `Real.differentiable_erf`: `erf` is differentiable * `Real.continuous_erf`: `erf` is continuous * `Real.strictMono_erf`: `erf` is strictly monotone Also adds `erf` to `docs/overview.yaml` under Special Functions. --- - [x] Builds successfully - [x] `lake exe runLinter` passes - [x] `lake exe mk_all --check` passes	t-analysis new-contributor awaiting-author	333/0	Mathlib.lean,Mathlib/Analysis/SpecialFunctions/Erf.lean,docs/overview.yaml	3	18	['SnirBroshi', 'christian-oudard', 'github-actions', 'j-loreaux', 'plp127']	j-loreaux assignee:j-loreaux	77-43773 2 months ago	77-80626 77 days ago	14-62757 14 days
33601	nielstron author:nielstron	feat(Computability/ContextFreeGrammar): Concatenation of CFGs is CFG	--- - [ ] depends on: #33599 - [ ] depends on: #33592 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-computability new-contributor blocked-by-other-PR	941/0	Mathlib/Computability/ContextFreeGrammar.lean	1	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	77-21486 2 months ago	unknown	unknown
34726	GrigorenkoPV author:GrigorenkoPV	feat(Analysis/SpecialFunctions/Trigonometric/Basic): sin and cos of multiples of π / 3	--- Merge of https://github.com/leanprover-community/mathlib4/pull/26349 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor	159/0	Mathlib/Algebra/Order/Monoid/NatCast.lean,Mathlib/Analysis/SpecialFunctions/Trigonometric/Basic.lean,Mathlib/Data/Nat/Cast/Defs.lean,MathlibTest/trigonometry.lean	4	1	['github-actions']	nobody	75-66911 2 months ago	unknown	unknown
34394	Citronhat author:Citronhat	feat(Algebra/Order/Ring): add constructors for linear ordered rings	Add constructors for ordered rings from `mul_nonneg` / `mul_pos` that derive `ZeroLEOneClass` from a linear order.	new-contributor t-algebra awaiting-author label:t-algebra$	31/14	Mathlib/Algebra/Order/Ring/Defs.lean,Mathlib/RingTheory/HahnSeries/Lex.lean	2	6	['Citronhat', 'Vierkantor', 'github-actions', 'leanprover-radar']	Vierkantor assignee:Vierkantor	75-13848 2 months ago	75-13848 75 days ago	12-18344 12 days
33493	michelsol author:michelsol	feat(RingTheory/Polynomial): An explicit formula for the Chebyshev polynomials of the first kind	Adds the following explicit formula on the Chebyshev polynomial of the first kind of order n. ${ T_{n}(x)\ =\ \sum \limits _{k=0}^{\lfloor {\frac {n}{2}}\rfloor } {\binom {n}{2k}} \left(\ X^{2}-1\ \right)^{k}\ X^{n-2k}}$ This explicit formula can be found [here](https://en.wikipedia.org/wiki/Chebyshev_polynomials#Explicit_expressions). There is a proof using complex numbers but it only works if the ring R = ℂ. The proof here is by induction and works in a commutative ring R. Mathlib seems to extend the definition of Chebyshev polynomials for $n \in \mathbb{Z}$ but this would make the formula more cumbersome with `n.natAbs` in place of `n`'s, so I expressed it on `n : ℕ` directly. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-ring-theory new-contributor awaiting-author	51/1	Mathlib/RingTheory/Polynomial/Chebyshev.lean	1	8	['YuvalFilmus', 'erdOne', 'github-actions', 'metakunt', 'michelsol']	chrisflav assignee:chrisflav	73-50087 2 months ago	73-50087 73 days ago	35-13883 35 days
26986	WangYiran01 author:WangYiran01	feat(Partition): add bijection for partitions with max part ≤ r	This PR adds a new theorem `partition_max_equals_bound` to `Mathlib.Combinatorics.Enumerative.Partition`. It constructs a bijection between: - The set of partitions of `n` in which `r ∈ π.parts` and all parts are `≤ r`, and - The set of partitions of `n - r` whose largest part is at most `r`. This provides a constructive proof via removing/adding `r` from/to the partition multiset, in line with classical enumerative combinatorics. Contributed by Yiran Wang.	awaiting-author t-combinatorics new-contributor merge-conflict	92/0	Mathlib/Combinatorics/Enumerative/Partition/Basic.lean,Mathlib/Data/Multiset/Lattice.lean	2	20	['WangYiran01', 'github-actions', 'jcommelin', 'kckennylau', 'kim-em', 'mathlib-merge-conflicts', 'mathlib4-merge-conflict-bot']	b-mehta assignee:b-mehta	70-84961 2 months ago	104-21429 104 days ago	120-65801 120 days
26168	oliver-butterley author:oliver-butterley	feat(MeasureTheory.VectorMeasure): variation defined as a supremum is equal to variation defined using the Hahn-Jordan decomposition	Add `signedMeasure_totalVariation_eq`: if `μ` is a `SignedMeasure` then variation defined as a supremum is equal to variation defined using the Hahn-Jordan decomposition. Co-authored-by: @yoh-tanimoto - [ ] depends on: #26165 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	blocked-by-other-PR new-contributor t-measure-probability merge-conflict	916/0	Mathlib.lean,Mathlib/MeasureTheory/VectorMeasure/Integral.lean,Mathlib/MeasureTheory/VectorMeasure/Variation/Defs.lean,Mathlib/MeasureTheory/VectorMeasure/Variation/Equiv.lean,Mathlib/MeasureTheory/VectorMeasure/Variation/Lemmas.lean	5	4	['github-actions', 'mathlib-merge-conflicts', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	70-65950 2 months ago	291-21817 291 days ago	15-64852 15 days
33969	goliath-klein author:goliath-klein	refactor(PiTensorProduct/{InjectiveNorm, ProjectiveNorm}): Currently, injectiveSeminorm = projectiveSeminorm	WIP / RFC! Arguably, `injectiveSeminorm` should be re-defined in Mathlib. See #34137 and [Zulip](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/injectiveSeminorm/with/568798261) for context. In this file, we collect some results about the current definition and a possible alternative. Contents: * A theorem `injectiveSeminorm_eq_projectiveSeminorm` formalizing the equality of the current definitions. However, I think it is unlikely that keeping the alternative characterization would be worth the effort. The interesting direction `(L2') ≤ (L1)` follows from `norm_eval_le_projectiveSeminorm` which is still present. The converse direction is [somewhat tautological](https://github.com/leanprover-community/mathlib4/pull/34137). A proof of `(L2) = (L1)` (probably requiring Hahn-Banach) might be more interesting. * A preliminary implementation of the injective seminorm as commonly understood. * Sufficient conditions for the multiplicativity property `‖⨂ m i‖_∧ = ∏ ‖m i‖` to hold. This implements a TBD item. --- Co-authored-by: Davood H. H. Tehrani [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	WIP t-analysis new-contributor large-import merge-conflict	774/387	Mathlib.lean,Mathlib/Analysis/Normed/Module/Dual.lean,Mathlib/Analysis/Normed/Module/HahnBanach.lean,Mathlib/Analysis/Normed/Module/PiTensorProduct/InjectiveSeminorm.lean,Mathlib/Analysis/Normed/Module/PiTensorProduct/LeastReasonable.lean,Mathlib/Analysis/Normed/Module/PiTensorProduct/ProjectiveSeminorm.lean,Mathlib/Analysis/Normed/Operator/Basic.lean,Mathlib/LinearAlgebra/PiTensorProduct.lean	8	3	['github-actions', 'goliath-klein', 'mathlib-merge-conflicts']	nobody	69-68311 2 months ago	unknown	unknown
33233	jazzits author:jazzits	feat(GroupTheory): add chosen group presentations and Tietze transformations (1) and (2)	Defines a notion of group presentation for G compatible with Mathlib.GroupTheory.PresentedGroup: generators `ι → G` whose range generates G, and relators `rels : Set (FreeGroup ι)` whose normal closure equals the kernel of `FreeGroup ι →* G`. Provides the canonical map `PresentedGroup P.rels →* G` and equivalences showing `PresentedGroup P.rels ≃* G` and invariance under changing presentations. Also formalizes Tietze moves (1)–(2) as equivalences of PresentedGroups: adding/removing a relator that lies in the normal closure of the others. TODO: moves (3)–(4) (add/remove generator with a defining relation). No existing definitions are modified	t-group-theory new-contributor awaiting-author	328/0	Mathlib.lean,Mathlib/GroupTheory/Presentation.lean	2	15	['github-actions', 'homeowmorphism', 'jazzits', 'kbuzzard', 'mathlib-merge-conflicts', 'plp127', 'tb65536']	tb65536 assignee:tb65536	69-10444 2 months ago	114-2991 114 days ago	5-43644 5 days
34725	GrigorenkoPV author:GrigorenkoPV	feat(RingTheory/RootsOfUnity/LowDegree): quadratic, cubic, quartic, quintic roots of unity	Closes https://github.com/leanprover-community/mathlib4/pull/25907 --- Merge of https://github.com/leanprover-community/mathlib4/pull/25907 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-ring-theory awaiting-author	247/0	Mathlib.lean,Mathlib/Algebra/CharP/Invertible.lean,Mathlib/Algebra/QuadraticDiscriminant.lean,Mathlib/RingTheory/RootsOfUnity/LowDegree.lean	4	22	['GrigorenkoPV', 'LLaurance', 'erdOne', 'github-actions', 'joneugster']	nobody	68-61534 2 months ago	73-50854 73 days ago	5-33486 5 days
34159	wangying11123 author:wangying11123	feat(Geometry/Euclidean/Similarity): Add Triangle similarity on oangle	Add theorems about triangles similarity on oangle	t-euclidean-geometry new-contributor awaiting-author	154/1	Mathlib/Geometry/Euclidean/Similarity.lean	1	8	['LLaurance', 'github-actions', 'jsm28', 'wangying11123']	jsm28 assignee:jsm28	68-9211 2 months ago	68-56440 68 days ago	7-47963 7 days
33050	mkaratarakis author:mkaratarakis	feat: lemmas for the analytic part of the proof of the Gelfond–Schneider theorem	Lemmas missing for the formalisation of the proof of the Gelfond–Schneider theorem --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-number-theory new-contributor WIP	238/0	Mathlib.lean,Mathlib/Analysis/Analytic/Basic.lean,Mathlib/Analysis/Analytic/Order.lean,Mathlib/Analysis/Complex/CauchyIntegral.lean,Mathlib/NumberTheory/Transcendental/AnalyticPart.lean,Mathlib/NumberTheory/Transcendental/AnalyticPart2.lean	6	113	['SnirBroshi', 'github-actions', 'j-loreaux', 'mkaratarakis', 'riccardobrasca', 'vihdzp']	riccardobrasca assignee:riccardobrasca	66-77991 2 months ago	77-11604 77 days ago	6-1877 6 days
23791	SEU-Prime author:SEU-Prime	Create AmiceTrans.lean	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict WIP t-number-theory new-contributor	2963/0	Mathlib.lean,Mathlib/Analysis/Normed/Ring/Lemmas2.lean,Mathlib/NumberTheory/Padics/AmiceTrans.lean,Mathlib/NumberTheory/Padics/PSAC.lean,Mathlib/NumberTheory/Padics/PSAC2.lean,Mathlib/NumberTheory/Padics/PSAC3.lean,Mathlib/NumberTheory/Padics/PiGammainPS.lean,Mathlib/NumberTheory/Padics/PsiandVar.lean,Mathlib/RingTheory/AdicCompletion/Lemma.lean,Mathlib/RingTheory/PowerSeries/Comp.lean,Mathlib/Topology/ContinuousMap/ZeroAtBot.lean	11	5	['SEU-Prime', 'github-actions', 'leanprover-community-bot-assistant', 'urkud']	nobody	66-50275 2 months ago	unknown	unknown
33281	michelsol author:michelsol	feat(Analysis/SpecialFunctions/Integrals): integral of 1/sqrt(1-x^2) and its integrability.	Add the integral of the derivative of arcsin and its integrability. --- - [ ] depends on: #33280 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor merge-conflict t-analysis	59/0	Mathlib/Analysis/SpecialFunctions/Integrability/Basic.lean,Mathlib/Analysis/SpecialFunctions/Integrals/Basic.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral/FundThmCalculus.lean	3	3	['github-actions', 'mathlib-dependent-issues', 'mathlib4-merge-conflict-bot']	nobody	66-19898 2 months ago	117-74123 117 days ago	0-811 13 minutes
29777	yuanyi-350 author:yuanyi-350	feat(Functional Analysis): closed Range Theorem	- [ ] depends on: #29151 [Corollary of Hahn-Banach theorem] - [ ] depends on: #29776 [refactor ContinuousLinearMap.isOpenMap by separating it into sublemmas] --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	WIP blocked-by-other-PR new-contributor awaiting-author t-analysis merge-conflict	237/25	Mathlib/Analysis/LocallyConvex/Separation.lean,Mathlib/Analysis/Normed/Operator/Banach.lean,Mathlib/Analysis/Normed/Operator/ClosedRange.lean,Mathlib/Analysis/RCLike/Lemmas.lean,Mathlib/Topology/Order/OrderClosed.lean	5	5	['github-actions', 'mathlib-merge-conflicts', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	faenuccio assignee:faenuccio	65-75483 2 months ago	unknown	unknown
29151	yuanyi-350 author:yuanyi-350	feat: Corollary of Hahn–Banach theorem	In this PR, I have proved [Rudin, Functional Analysis (Theorem 3.7)][rudin1991] which is a step in proving the Closed Range Theorem. Also, I have added tags for the corresponding theorems in Rudin to mathlib. 3.7 Theorem. Suppose B is a convex, balanced, closed set in a locally convex space $X, x_0 \in X$, but $x_0 \notin B$. Then there exists $\Lambda \in X^$ such that $\|\Lambda x\| \leq 1$ for all $x \in B$, but $\Lambda x_0>1$ proof. Since $B$ is closed and convex, we can apply (b) of Theorem 3.4, with $A=\{ x_0 \}$ , to obtain $\Lambda_1 \in X^$ such that $\Lambda_1 x_0=r e^{i \theta}$ lies outside the closure $K$ of $\Lambda_1(B)$. Since $B$ is balanced, so is $K$. Hence there exists $s, 0 List.Vector.* - ... Deletions: - Nat.bit1_add_bit1 - ... Any other comments you want to keep out of the PR commit should go below the `---`, and placed outside this HTML comment, or else they will be invisible to reviewers. If this PR depends on other PRs, please list them below this comment, using the following format: - [ ] depends on: #xyz [optional extra text] --> [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-author new-contributor large-import t-analysis merge-conflict	70/1	Mathlib/Analysis/LocallyConvex/Separation.lean,Mathlib/Analysis/RCLike/Lemmas.lean,Mathlib/Topology/Order/OrderClosed.lean	3	17	['faenuccio', 'fpvandoorn', 'github-actions', 'mathlib-merge-conflicts', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'mcdoll', 'themathqueen', 'yuanyi-350']	faenuccio assignee:faenuccio	65-71106 2 months ago	213-18534 213 days ago	2-2914 2 days
33712	wangying11123 author:wangying11123	feat(Geometry/Euclidean/Angle/Unoriented/Projection): Add sameray_orthogonalProjection_vsub_of_angle_lt	Add sameray_orthogonalProjection_vsub_of_angle_lt `sameray_orthogonalProjection_vsub_of_angle_lt` When an angle is acute, the vector to the orthogonal projection lies in the same ray as the given direction vector.	new-contributor t-euclidean-geometry awaiting-author	20/0	Mathlib/Geometry/Euclidean/Angle/Unoriented/Projection.lean	1	4	['JovanGerb', 'github-actions', 'j-loreaux']	JovanGerb assignee:JovanGerb	63-86228 2 months ago	63-86328 63 days ago	39-3093 39 days
33786	hdmkindom author:hdmkindom	feat(Analysis/Matrix): add Jacobian matrix for matrix-valued functions	This PR introduces the Jacobian matrix for matrix-valued functions `F : Matrix m n ℝ → Matrix p q ℝ`. The Jacobian matrix `jacobianMatrix F X` at point `X` is indexed by `(p × q) × (m × n)`, where each entry represents the partial derivative with respect to a basis element. To handle instance-mismatch issues with matrix norms, we use local Frobenius norm instances. mkdir Analysis/Matrix/Jacobian.lean ## Main definitions - `jacobianMatrix F X`: The Jacobian matrix at point `X`, defined by `jacobianMatrix F X (i, k) (j, l) = (fderiv ℝ F X (Matrix.single j l 1)) i k` ## Main theorems - `fderiv_eq_jacobian_mul`: Express the Fréchet derivative as a contraction with the Jacobian - `jacobianMatrix_comp`: Chain rule for Jacobian matrices - `jacobianMatrix_linear`, `jacobianMatrix_id`, `jacobianMatrix_const`: Basic properties - `jacobianMatrix_add`, `jacobianMatrix_smul`: Linearity properties	t-analysis new-contributor awaiting-author	219/0	Mathlib.lean,Mathlib/Analysis/Matrix/Jacobian.lean	2	11	['erdOne', 'github-actions', 'jcommelin']	sgouezel assignee:sgouezel	63-85876 2 months ago	64-230 63 days ago	39-30128 39 days
30667	FrederickPu author:FrederickPu	feat(‎Mathlib/Algebra/Group/Subgroup/Pointwise): subgroup mul	Title: feat: pointwise products for subgroups Description: showed the point-wise product of disjoint subgroups is equivalent to their Cartesian product. Based on https://leanprover.zulipchat.com/#narrow/channel/113488-general/topic/useful.20group.20theory.20lemmas/with/546738566. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra new-contributor label:t-algebra$	28/0	Mathlib/Algebra/Group/Subgroup/Pointwise.lean	1	23	['FrederickPu', 'eric-wieser', 'github-actions', 'plp127', 'tb65536']	nobody	63-84737 2 months ago	64-2971 64 days ago	1-14123 1 day
33793	LTolDe author:LTolDe	feat(MeasureTheory/Constructions/Polish/Basic): add lemma AnalyticSet.inter_nonempty_of_nowhereMeagre	add lemma AnalyticSet.inter_nonempty_of_nowhereMeagre, the main ingredient for the proof of the Effros' Theorem, see [#mathlib4 > Effros Theorem](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Effros.20Theorem/with/566543328) introduce definition of a nowhere meagre set --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-measure-probability new-contributor awaiting-author	37/0	Mathlib/MeasureTheory/Constructions/Polish/Basic.lean,Mathlib/Order/Filter/Basic.lean,Mathlib/Topology/GDelta/Basic.lean	3	8	['MichaelStollBayreuth', 'erdOne', 'github-actions', 'j-loreaux']	kex-y assignee:kex-y	63-80494 2 months ago	63-80700 63 days ago	39-4185 39 days
35313	LexinonCraft author:LexinonCraft	feat: IMO 2025 Q4	This adds a solution for problem 4 from the International Math Olympiad 2025. ---	IMO new-contributor awaiting-author	631/0	Archive.lean,Archive/Imo/Imo2025Q4.lean	2	4	['LexinonCraft', 'github-actions', 'jsm28']	jsm28 assignee:jsm28	63-50368 2 months ago	63-50368 63 days ago	3-29649 3 days
33276	NicolaBernini author:NicolaBernini	feat: Rename List.reverse_perm to List.reverse_perm_self and List.reverse_perm' to List.reverse_perm_iff	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor awaiting-author t-data merge-conflict	17/15	Mathlib/Algebra/BigOperators/Group/List/Basic.lean,Mathlib/Data/Finset/Dedup.lean,Mathlib/Data/List/Basic.lean,Mathlib/Data/List/Defs.lean,Mathlib/Data/List/Perm/Lattice.lean,Mathlib/Data/List/Permutation.lean,Mathlib/Data/Multiset/Defs.lean,Mathlib/NumberTheory/Divisors.lean	8	5	['Ruben-VandeVelde', 'github-actions', 'mathlib-merge-conflicts']	kim-em assignee:kim-em	63-34112 2 months ago	114-12385 114 days ago	3-79472 3 days
34674	Citronhat author:Citronhat	feat(Algebra/Order/Ring): replace ENNReal lemmas with WithTop versions	* Add `WithTop` versions of basic multiplicative order lemmas. * Use the new `WithTop` lemmas to replace `ENNReal` proofs and address six TODOs. * Fix a typo in the `pos_of_ne_zero` alias name.	new-contributor t-algebra merge-conflict label:t-algebra$	46/15	Mathlib/Algebra/Order/Monoid/Canonical/Defs.lean,Mathlib/Algebra/Order/Ring/WithTop.lean,Mathlib/Data/ENNReal/Operations.lean	3	5	['Citronhat', 'Ruben-VandeVelde', 'github-actions', 'mathlib-merge-conflicts']	Ruben-VandeVelde assignee:Ruben-VandeVelde	63-13846 2 months ago	63-13847 63 days ago	16-81273 16 days
28246	Sebi-Kumar author:Sebi-Kumar	feat(AlgebraicTopology/FundamentalGroupoid): the n-sphere is simply connected for n > 1	Prove that the `n`-dimensional sphere (i.e., the unit sphere centered at the origin in `(n + 1)`-dimensional real Euclidean space) is a simply connected space for `n > 1`. This proof follows Hatcher's "Algebraic Topology"; we first prove a general lemma about decomposing loops and then exploit the fact that non-surjective loops in the sphere are homotopically trivial. Note: To get this file to build, I edited `Mathlib/Tactic/Linter/DirectoryDependency.lean` to remove the restrictions on AlgebraicTopology files importing Geometry, NumberTheory, and FieldTheory files. Thank you to those who shared their expertise [here](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Warning.20that.20AlgebraicTopology.20can't.20import.20SetTheory/with/533833638). As I understand it, this is just a short-term solution, so I would appreciate feedback on what to do about this situation. Note: I am unsure where exactly the file `SimplyConnectedSphere.lean` should go or whether that is an appropriate name for the file, so feedback there would be appreciated. --- To provide additional context, this code was written as a part of the Fields Undergraduate Summer Research Program at the University of Western Ontario under the supervision of Chris Kapulkin and Daniel Carranza. - [x] depends on: #28208 - [x] depends on: #28198 - [x] depends on: #28185 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebraic-topology new-contributor awaiting-author	343/3	Mathlib.lean,Mathlib/AlgebraicTopology/FundamentalGroupoid/SimplyConnectedSphere.lean,Mathlib/Tactic/Linter/DirectoryDependency.lean	3	17	['dagurtomas', 'github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'robin-carlier']	robin-carlier assignee:robin-carlier	61-11632 2 months ago	61-11632 61 days ago	13-68576 13 days
35620	inaciovasquez2020 author:inaciovasquez2020	feat(Fintype): choose element from nonempty finite type	This PR adds a noncomputable choice function for finite types with nonzero cardinality. * `Fintype.chooseOfCardNeZero` provides a witness of `α` from `[Fintype α]` assuming `Fintype.card α ≠ 0`. * A regression test is included in `MathlibTest/Fintype/ChooseOfCardNeZero.lean`. The construction follows existing mathlib choice patterns and is explicitly marked `noncomputable`.	t-data new-contributor	21/0	Mathlib.lean,Mathlib/Data/Fintype/Choose.lean,MathlibTest/Fintype/ChooseOfCardNeZero.lean	3	4	['github-actions', 'plp127', 'vihdzp']	nobody	59-34768 2 months ago	unknown	unknown
33746	ster-oc author:ster-oc	feat(Algebra/Module/ZLattice): align `ZSpan.floor` to `Int.floor` API	This PR adds some of the existent lemmas about `Int.floor`, `Int.ceil` and `Int.fract` to the `ZSpan` namespace. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra new-contributor merge-conflict label:t-algebra$	353/145	Mathlib/Algebra/Module/ZLattice/Basic.lean,Mathlib/Algebra/Order/Floor/Ring.lean,Mathlib/Topology/Algebra/Order/Floor.lean	3	8	['github-actions', 'joelriou', 'mathlib-merge-conflicts', 'ster-oc']	joelriou assignee:joelriou	58-30744 1 month ago	58-30744 58 days ago	30-19397 30 days
31766	SuccessMoses author:SuccessMoses	feat(Topology/EMetricSpace): continuity of arc length	fixes half of #31751 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-topology awaiting-author merge-conflict	396/0	Mathlib.lean,Mathlib/Topology/EMetricSpace/ArcLength.lean,Mathlib/Topology/EMetricSpace/BoundedVariation.lean	3	40	['SnirBroshi', 'SuccessMoses', 'alreadydone', 'github-actions', 'grunweg', 'j-loreaux', 'mathlib-merge-conflicts']	nobody	57-62441 1 month ago	133-63311 133 days ago	2-76065 2 days
26479	thefundamentaltheor3m author:thefundamentaltheor3m	feat(Analysis/Complex/CauchyIntegral): Cauchy–Goursat for Unbounded Rectangles	In this PR, we prove versions of the Cauchy-Goursat theorem where the contours in question are rectangular and unbounded (ie, where the contours look like the $\bigsqcup$ symbol). I am not sure if I have formalised these in the best way, or if `Analysis.Complex.CauchyIntegral` is the best place for them (it might be prudent to reorganise the file into multiple files at some point), but I believe this is a useful result. Suggestions welcome. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-analysis sphere-packing awaiting-author	205/0	Mathlib/Analysis/Complex/CauchyIntegral.lean	1	6	['github-actions', 'j-loreaux', 'loefflerd', 'mathlib4-merge-conflict-bot', 'thefundamentaltheor3m', 'wwylele']	urkud assignee:urkud	56-62561 1 month ago	56-62561 56 days ago	34-9948 34 days
33247	sun123zxy author:sun123zxy	feat(Mathlib/RingTheory/Ideal/Cotangent): dimension of cotangent spaces	It is shown that the span rank of the maximal ideal of a local ring equals the dimension of the cotangent space if the maximal ideal is finitely generated. To avoid unnecessary imports, the original `Mathlib/RingTheory/Nakayama` is now moved to `Mathlib/RingTheory/Nakayama/Basic`. --- - [ ] depends on: #33359 - [ ] depends on: #33361 - [ ] depends on: #35651 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	file-removed new-contributor t-ring-theory WIP blocked-by-other-PR merge-conflict	140/27	Mathlib.lean,Mathlib/RingTheory/Ideal/Cotangent.lean,Mathlib/RingTheory/Ideal/KrullsHeightTheorem.lean,Mathlib/RingTheory/Ideal/Quotient/Operations.lean,Mathlib/RingTheory/LocalRing/Module.lean,Mathlib/RingTheory/LocalRing/Quotient.lean,Mathlib/RingTheory/Nakayama/Basic.lean,Mathlib/RingTheory/Nakayama/SpanRank.lean,Mathlib/RingTheory/Regular/RegularSequence.lean,Mathlib/RingTheory/Support.lean	10	13	['erdOne', 'github-actions', 'mathlib-bors', 'mathlib-merge-conflicts', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'sun123zxy']	nobody	56-58777 1 month ago	115-65925 115 days ago	3-69288 3 days
35735	mkaratarakis author:mkaratarakis	feat(NumberTheory): analytical properties and lower bounds for Gelfond-Schneider auxiliary function	This PR is the third component in the formalization of the Gelfond-Schneider Theorem (Hilbert's Seventh Problem). It connects the algebraically constructed auxiliary function `R(x)` to its analytical properties, establishing the exact order of vanishing and the fundamental lower bound on the norm of its non-zero derivative evaluation. Following the argument in Loo-Keng Hua's Introduction to Number Theory (Chapter 17.9, equations (4) and (5)), we define the minimal non-vanishing derivative order $r$ and scale the evaluation to an algebraic integer to compute its norm. 1. (`iteratedkDeriv_R_eq_zero` & `order_geq_n`): We verify that the coefficient vector $\eta$ (chosen via Siegel's lemma in the previous PR) forces the first $n$ derivatives of the auxiliary function $R(x)$ to vanish at the points $x \in \{1, 2, \dots, m\}$. Consequently, the analytical order of $R(x)$ at these points is at least $n$. 2. We extract $r$, the exact minimal order of vanishing of $R(x)$ among all points $1 \le l \le m$, and prove that $n \le r$. 3. We define the non-zero algebraic number $\rho = (\log \alpha)^{-r} R^{(r)}(l_0)$. 4. We prove the crucial textbook step that scaling $\rho$ by $c_1^{r+2mq}$ (formalized here as `cρ`) results in an algebraic integer in $\mathcal{O}_K$. 5. Because $c_1^{r+2mq} \rho$ is a non-zero algebraic integer, the absolute value of its norm is at least $1$. We use this to formally prove the strict lower bound on the absolute norm of the unscaled $\rho$: $\|N(\rho)\| > c_1^{-h(r+2mq)} > c_5^{-r}$. --- - [ ] depends on: #35734 [optional extra text] [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-number-theory new-contributor blocked-by-other-PR	1141/0	Mathlib.lean,Mathlib/NumberTheory/Transcendental/GelfondSchneider/MainAlg.lean,Mathlib/NumberTheory/Transcendental/GelfondSchneider/MainAlgSetup.lean,Mathlib/NumberTheory/Transcendental/GelfondSchneider/MainOrder.lean	4	3	['github-actions', 'mathlib-dependent-issues']	nobody	56-45858 1 month ago	unknown	unknown
20238	maemre author:maemre	feat(Computability/DFA): Closure of regular languages under some set operations	This shows that regular languages are closed under complement and intersection by constructing DFAs for them. --- Closure under all other operations will be proved when someone adds the proof for DFA<->regular expression equivalence, so they are not part of this PR. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-computability merge-conflict awaiting-author awaiting-zulip	159/0	Mathlib/Computability/DFA.lean,Mathlib/Computability/Language.lean	2	60	['EtienneC30', 'YaelDillies', 'github-actions', 'maemre', 'mathlib4-merge-conflict-bot', 'meithecatte', 'urkud']	nobody	55-20782 1 month ago	unknown	unknown
22361	rudynicolop author:rudynicolop	feat(Computability/NFA): nfa closure properties	Add the closure properties union, intersection and reversal for NFA. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-computability merge-conflict awaiting-author awaiting-zulip	218/2	Mathlib/Computability/Language.lean,Mathlib/Computability/NFA.lean	2	91	['EtienneC30', 'b-mehta', 'ctchou', 'github-actions', 'leanprover-community-bot-assistant', 'meithecatte', 'rudynicolop']	nobody	55-20766 1 month ago	unknown	unknown
35746	ThomasMoulin-hub author:ThomasMoulin-hub	feat (Algebra/Endomorphisms): add kernels lemma from the missing undergraduate mathematics in mathlib	Add helper theorem inside Mathlib.Algebra.Polynomial.Smeval.lean and created a new file Mathlib/RingTheory/Polynomial/KernelDecomposition.lean that implements the kernels lemma from the missing undergraduate mathematics in mathlib list. This file also contains intermediate results needed for the main lemma.	new-contributor	75/0	Mathlib/Algebra/Polynomial/Smeval.lean,Mathlib/RingTheory/Polynomial/Basic.lean	2	2	['github-actions']	nobody	54-58606 1 month ago	unknown	unknown
23929	meithecatte author:meithecatte	feat(Computability/NFA): improve bound on pumping lemma	--- - [x] depends on: #25321 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-computability awaiting-zulip new-contributor awaiting-author	101/10	Mathlib/Computability/EpsilonNFA.lean,Mathlib/Computability/NFA.lean	2	42	['YaelDillies', 'dagurtomas', 'github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'meithecatte']	nobody	54-40795 1 month ago	318-70094 318 days ago	0-37135 10 hours
35128	DAE123456 author:DAE123456	feat : Define anti_pascal	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra new-contributor awaiting-author label:t-algebra$	81/0	Archive.lean,Archive/Imo/Imo2018Q3.lean	2	5	['DAE123456', 'github-actions', 'grunweg', 'vihdzp']	nobody	54-38321 1 month ago	unknown	unknown
8102	miguelmarco author:miguelmarco	feat(Tactic): add `unify_denoms` and `collect_signs` tactics	This PR adds four new tactics: - `unify_denoms` tries to put expressions with several divisions in a form with only one division. In the case of fields, it works similarly to `field_simp`, but if the hypothesis about denominators being nonzero are not present, it assumes them, and leaves them as new goals to prove. In that sense, it is an "unsafe" tactic (but can be useful nevertheless, for example when you can't find which exact hypothesis is missing). It also works with expressions of naturals and Euclidean domains, assuming the corresponding hypothesis about the denominators dividing the numerators. - `unify_denoms!` extends `unify_denoms` to work with (in)equalities, assuming also that the denominators, once in normal form, are positive. - `collect_signs` works similarly with expressions using sums and substractions: it tries to put them in a form of one sum minus other sum. In the case of working with naturals, it assumes that we never substract a bigger number from a smaller one. Both are implemented essentially as a macro that combines several rewriting rules. Some new lemmas with the corresponding rules are added. ---	please-adopt new-contributor merge-conflict modifies-tactic-syntax good first issue t-meta	407/0	Mathlib.lean,Mathlib/Algebra/EuclideanDomain/Basic.lean,Mathlib/Tactic.lean,Mathlib/Tactic/CollectSigns.lean,Mathlib/Tactic/UnifyDenoms.lean,MathlibTest/unify_denoms.lean,scripts/noshake.json	7	55	['Paul-Lez', 'YaelDillies', 'github-actions', 'joneugster', 'kbuzzard', 'mathlib4-merge-conflict-bot', 'miguelmarco']	nobody	54-5093 1 month ago	unknown	unknown
35603	2500223210-max author:2500223210-max	feat(GroupTheory/Frattini): add more theorems	Add some contents about frattini subgroup into Mathlib GroupTheory Frattini.lean,including * (convenient lemma)A subgroup contained in all maximal subgroup is contained in the FRattini subgroup * A subgroup (say H) has a proper complement (meaning for some proper subgroup K, K and H generate the whole group)if and only if it is not contained in the Frattini subgroup. * A group is cyclic iff its Frattini factor(the quotient group wrt Frattini subgroup) is cyclic. * The Frattini factor of a finite p-group is elementary abelian(that is,an abelian group G with Gᵖ={1}) * A finite p-group has trivial Frattini subgroup iff the group is elementary abelian. * Burnside theorem of Frattini factor of finite p-group. ---	new-contributor t-group-theory large-import awaiting-author	764/1	Mathlib/GroupTheory/Frattini.lean	1	3	['github-actions', 'tb65536']	nobody	54-2774 1 month ago	unknown	unknown
33791	PhoenixIra author:PhoenixIra	feat: Generalization of FixedPointApproximants to CompletePartialOrder	--- This PR provides a generalization of FixedPointApproximants to CompletePartialOrder. Not every theorem can be generalized, as sometimes we require additional conditions (namely `x ≤ f x`) in order to guarantee that the set is directed and thus the supremum is well-defined. This is not necessary in a CompleteLattice. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-order merge-conflict	223/100	Mathlib/Order/CompletePartialOrder.lean,Mathlib/SetTheory/Ordinal/FixedPointApproximants.lean	2	21	['PhoenixIra', 'github-actions', 'mathlib-merge-conflicts', 'vihdzp']	PhoenixIra and vihdzp assignee:PhoenixIra assignee:vihdzp	53-67478 1 month ago	53-67478 53 days ago	38-8977 38 days
35734	mkaratarakis author:mkaratarakis	feat(NumberTheory): matrix bounds and Siegel's lemma application for Gelfond-Schneider	This PR is the second component in the formalization of the Gelfond-Schneider Theorem (Hilbert's Seventh Problem), establishing the transcendence of $\alpha^\beta$. Building on the algebraic setup from the previous PR #35733, this file establishes analytical bounds on the linear system matrix and applies Siegel's Lemma (Lemma 8.2) to extract a bounded, non-trivial integer solution vector. We establish the exact upper bounds required to construct the auxiliary integer function $R(x)$. `c₃` and Matrix Bounds (`house_matrixA_le`)*: We define the bounding constant $c_3$, which aggregates the base bounds $c_2$ and the maximal houses of the algebraic preimages $\alpha', \beta', \gamma'$. Through extensive algebraic manipulation, we formally prove that the house of the entries in our linear system matrix $A$ is strictly bounded by $c_3^n n^{(n - 1) / 2}$. Using the bounds established above, we apply `house.exists_ne_zero_int_vec_house_le` (a formalization of Lemma 8.2, p. 490) to guarantee the existence of a non-trivial vector of algebraic integers $\eta$ in the kernel of $A$. We define the solution bounding constant $c_4$ and prove the textbook bound that the house of our resulting coefficient vector $\eta$ satisfies $\forall k, \\|\eta_k\\| \leq c_4^n * n^{(n + 1) / 2}$. - [ ] depends on: #35733 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-number-theory blocked-by-other-PR	872/5	Mathlib.lean,Mathlib/NumberTheory/NumberField/House.lean,Mathlib/NumberTheory/Transcendental/GelfondSchneider/MainAlg.lean,Mathlib/NumberTheory/Transcendental/GelfondSchneider/MainAlgSetup.lean	4	3	['github-actions', 'mathlib-dependent-issues']	nobody	52-8284 1 month ago	unknown	unknown
26013	tsuki8 author:tsuki8	feat(Data/Finset/Card,Data/Set/Finite/Basic): TODO needs a better title	add `card_bijOn` and `finset_subset_preimage_of_finite_image` Add `card_bijOn`: proves that for a bijection between finsets, their cardinalities are equal Add `finset_subset_preimage_of_finite_image`: constructs a finset subset preserving image cardinality Co-authored-by: Junyu Guo --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-author t-data new-contributor	15/0	Mathlib/Data/Finset/Card.lean,Mathlib/Data/Set/Finite/Basic.lean	2	6	['Ruben-VandeVelde', 'github-actions', 'mathlib-merge-conflicts']	nobody	51-42489 1 month ago	295-22222 295 days ago	13-83428 13 days
35442	dhyan-aranha author:dhyan-aranha	feat: Affine line with doubled origin counter example	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor awaiting-author t-algebraic-geometry	305/0	Counterexamples.lean,Counterexamples/AffineLineWithDoubledOrigin.lean,Mathlib/AlgebraicGeometry/Limits.lean,Mathlib/Topology/Category/TopCat/Limits/Pullbacks.lean	4	21	['BryceT233', 'chrisflav', 'dhyan-aranha', 'github-actions']	nobody	51-15419 1 month ago	64-3424 64 days ago	0-2563 42 minutes
28286	bwangpj author:bwangpj	feat(Geometry/Manifold/ContMDiff): basic lemmas for analytic (`C^ω`) functions	Add basic lemmas relating `ContMDiff` in the `C^ω` case to being `Analytic` on charts. This is upstreamed from [https://github.com/girving/ray](https://github.com/girving/ray). Co-authored-by: Geoffrey Irving --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-author t-differential-geometry new-contributor	36/0	Mathlib/Geometry/Manifold/ContMDiff/Defs.lean	1	14	['bwangpj', 'girving', 'github-actions', 'grunweg', 'kbuzzard', 'mathlib-merge-conflicts', 'sgouezel']	sgouezel assignee:sgouezel	50-27957 1 month ago	225-24307 225 days ago	22-76960 22 days
34940	michaellee94 author:michaellee94	feat: the graph of a continuous function on a $C^n$ manifold is a $C^n$ manifold	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-differential-geometry new-contributor awaiting-author	536/0	Mathlib.lean,Mathlib/Geometry/Manifold/ChartedSpace.lean,Mathlib/Geometry/Manifold/Instances/Graph.lean,Mathlib/Geometry/Manifold/IsManifold/Basic.lean,Mathlib/Topology/Constructions/Graph.lean	5	79	['botbaki-review', 'github-actions', 'grunweg', 'michaellee94', 'ocfnash']	ocfnash assignee:ocfnash	47-84617 1 month ago	49-64812 49 days ago	14-83240 14 days
35332	yisiox author:yisiox	feat(Computability): regular expressions match a regular language	This PR adds a proof that the language matched by a regular expression is a regular language. This is achieved by the following constructions and proofs of their correctness - A DFA `epsilon` which accepts the empty language - A DFA `char (a : α)` which accepts the language containing only a single symbol - An Epsilon-NFA `concat (M₁ : εNFA α σ₁) (M₂ : εNFA α σ₂)` which accepts the concatenation of the languages of two Epsilon-NFAs - An Epsilon-NFA `kstar (M : εNFA α σ)` which accepts the Kleene star of a language of an Epsilon-NFA The following theorems on closure are added - `IsRegular.zero` - `IsRegular.one` - `IsRegular.top` - `IsRegular.singleton` - `IsRegular.mul` - `IsRegular.kstar` which demonstrates - `IsRegular.matches` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-computability new-contributor	475/0	Mathlib/Computability/DFA.lean,Mathlib/Computability/EpsilonNFA.lean	2	2	['github-actions']	nobody	47-73724 1 month ago	unknown	unknown
14313	grhkm21 author:grhkm21	feat(RepresentationTheory/FdRep): FdRep is a full subcategory of Rep	``` /-- Equivalence between `FDRep` and the full subcategory of finite dimensional `Rep`. -/ def equivFiniteDimensional : FDRep k G ≌ FullSubcategory (fun V : Rep k G ↦ FiniteDimensional k V) ```	merge-conflict t-algebra t-category-theory new-contributor label:t-algebra$	47/8	Mathlib/RepresentationTheory/FDRep.lean	1	21	['fpvandoorn', 'github-actions', 'grhkm21', 'joelriou', 'kim-em', 'mathlib-bors']	nobody	47-10783 1 month ago	unknown	unknown
33592	nielstron author:nielstron	feat(Computability/ContextFreeGrammar): mapping between two types of nonterminal symbols	This PR picks up https://github.com/leanprover-community/mathlib4/pull/15895 and resolves the failing lemma by redefining Good symbols. --- I checked that https://github.com/leanprover-community/mathlib4/pull/13514 builds correctly when based on this build. PR for that is #33599 This is my first contribution please let me know of any changes I should outline. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-author t-computability new-contributor	160/0	Mathlib/Computability/ContextFreeGrammar.lean	1	34	['YaelDillies', 'github-actions', 'madvorak', 'nielstron']	nobody	46-86151 1 month ago	96-28278 96 days ago	10-67951 10 days
35144	daniel-carranza author:daniel-carranza	feat(CategoryTheory/Enriched): tensor product of enriched categories	For a braided monoidal category `V`, defines the tensor product of `V`-categories `C` and `D`, and shows that the type of `V`-functors out of the tensor product `C \times D` is equivalent to the type of "enriched bifunctors" `EnrichedBifunctor V C D`. --- This work originates from infinity-cosmos project, where it is used to formalize the notion of cotensors in an enriched category. There are some additional coherence lemmas in a braided monoidal category which have been added. Currently, line 209 violates the style guideline that terminal simp calls should not be squeezed. When I tried to replace this with a single `simp`, I get an error message: `maximum recursion depth has been reached`. Any suggestions (either with this or anything else) are greatly appreciated - thank you! [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-category-theory infinity-cosmos awaiting-author	333/0	Mathlib.lean,Mathlib/CategoryTheory/Enriched/TensorProductCategory.lean,Mathlib/CategoryTheory/Monoidal/Braided/Basic.lean	3	12	['daniel-carranza', 'emilyriehl', 'github-actions', 'joelriou', 'robin-carlier']	nobody	46-81858 1 month ago	unknown	unknown
35436	daniel-carranza author:daniel-carranza	feat(CategoryTheory/Monoidal/Closed): Prove the isomorphism of internal hom objects C(x \otimes y, z) and C(y, C(x, z))	Prove the currying-uncurrying isomorphism `C(x \otimes y, z) \iso C(y, C(x, z))` between internal hom objects of a closed monoidal category `C`. --- This result is connected to the infinity-cosmos project, and is used to prove that a closed monoidal category enriched in itself admits all cotensors. ~Line 81 currently contains a one-line proof in tactics mode `exact rfl`. When trying to use `rfl` outside of tactics mode, an error is thrown~ (Fixed, thank you @robin-carlier!). Any help with this (or any other aspect of the formalization) is greatly appreciated! [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-category-theory infinity-cosmos delegated	89/0	Mathlib.lean,Mathlib/CategoryTheory/Monoidal/Closed/InternalCurrying.lean	2	15	['dagurtomas', 'daniel-carranza', 'github-actions', 'joelriou', 'mathlib-bors', 'riccardobrasca', 'robin-carlier']	adamtopaz assignee:adamtopaz	46-73297 1 month ago	54-61436 54 days ago	7-65383 7 days
35504	JoaBjo author:JoaBjo	feat(Probability/Distributions/Exponential): add MGF, moments, and memoryless property	feat(Probability/Distributions/Exponential): add MGF, moments, and memoryless property Add the main analytic results for the exponential distribution: - moment-generating function `mgf id (expMeasure r) t = r / (r - t)` for `t < r` - mean `∫ x, x ∂(expMeasure r) = r⁻¹` - variance `Var[id; expMeasure r] = r⁻¹ ^ 2` - `ℒp` membership for all `p` - tail probability `P(X > x) = exp (-(r * x))` - memoryless property `P(X > s + t \| X > s) = P(X > t)` The MGF is computed by reducing to the known improper integral `∫ exp(c * x)` on `Ioi`, and integrability is deduced by contradiction from the positive closed-form value. The mean and variance are computed via the Gamma function integral `∫₀^∞ x^(n-1) exp(-r x) dx = Γ(n) / rⁿ`. The memoryless property follows from the exponential identity `exp(-(r(s+t))) = exp(-rt) * exp(-rs)`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-measure-probability	200/0	Mathlib/Probability/Distributions/Exponential.lean	1	6	['JoaBjo', 'Timeroot', 'github-actions']	kex-y assignee:kex-y	46-73261 1 month ago	46-73321 46 days ago	15-83262 15 days
27226	xcloudyunx author:xcloudyunx	feat(Combinatorics/SimpleGraph): Add Subgraph.inclusion_edge_apply_coe and inclusion_edgeSet_apply_coe	This PR continues the work from #25248. Original PR: https://github.com/leanprover-community/mathlib4/pull/25248	awaiting-author t-combinatorics new-contributor merge-conflict	14/0	Mathlib/Combinatorics/SimpleGraph/Subgraph.lean	1	4	['b-mehta', 'github-actions', 'mathlib-merge-conflicts', 'xcloudyunx']	b-mehta assignee:b-mehta	46-73251 1 month ago	253-53397 253 days ago	25-82865 25 days
33688	Citronhat author:Citronhat	feat(PMF): add expectation lemmas for Poisson PMF	This PR adds some basic results about the Poisson distribution, its `PMF`, and its expectation. New lemmas: * `poissonPMF_apply` — an unfolding lemma for `poissonPMF`. * `poissonPMFReal_mul_eq_succ_mul` — the standard recursion identity for the Poisson mass function. * `poissonPMFReal_hasSum_nmul` — shows that `fun n ↦ poissonPMFReal r n * n` has sum `r`. * `poissonPMF_tsum_nmul` — the corresponding identity at the level of the `PMF`. * `poissonPMF_coe_tsum_nmul` — the same result after coercion to `ℝ`. Both `ℝ`-valued and `ℝ≥0∞`-valued formulations are included so that these results can be used conveniently in both Lebesgue and Bochner integration contexts.	new-contributor t-measure-probability awaiting-author merge-conflict	21/0	Mathlib/Probability/Distributions/Poisson.lean	1	11	['Citronhat', 'DavidLedvinka', 'github-actions', 'mathlib-merge-conflicts', 'urkud']	urkud assignee:urkud	46-55231 1 month ago	57-69880 57 days ago	47-73664 47 days
34005	MSpill author:MSpill	feat: inverse function theorem for manifolds (concrete version)	Proves the inverse function theorem for manifolds: given manifolds $M, N$ and a $C^n$ map $f : M \to N$ whose differential is a linear isomorphism at $p \in M$, then $f$ is a local diffeomorphism at $p$, provided that both $p$ and its image are interior points. The proof proceeds in 4 main steps: 1. Define composition of partial diffeomorphisms 2. Show that the extended chart at an interior point can be restricted to an open set on which it is a partial diffeomorphism, viewing the model vector space as a manifold modelled on itself trivially 3. Use the inverse function theorem (applied to $f$ written in coordinates) to obtain a partial diffeomorphism between model vector spaces 4. Compose with chart diffeomorphisms to obtain a partial diffeomorphism between the manifolds. ------ [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-author t-differential-geometry new-contributor merge-conflict	232/3	Mathlib/Geometry/Manifold/LocalDiffeomorph.lean	1	12	['MSpill', 'github-actions', 'grunweg', 'mathlib-merge-conflicts']	grunweg assignee:grunweg	46-54986 1 month ago	unknown	unknown
34830	parabamoghv author:parabamoghv	feat(CategoryTheory/Monoidal): add definition of categorical groups	This PR defines of categorical groups, also known as coherent 2-groups, in mathlib. Motivation: Categorical groups are well-studied structures in monoidal category theory, but are not currently available in mathlib. The definitions in this PR follow the existing design patterns used for Category, MonoidalCategory, and BraidedCategory. This PR focuses on setting up the core structure and notation. Basic lemmas and further developments will be provided in a subsequent PR. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-category-theory new-contributor WIP merge-conflict	163/0	Mathlib.lean,Mathlib/CategoryTheory/Monoidal/CategoricalGroups/Basic.lean	2	27	['dagurtomas', 'github-actions', 'mathlib-merge-conflicts', 'parabamoghv', 'robin-carlier']	robin-carlier assignee:robin-carlier	46-43706 1 month ago	61-25746 61 days ago	5-9878 5 days
36326	Arnav-panjla author:Arnav-panjla	Feat/gaussian schwartz map	feat(Analysis/SpecialFunctions/Gaussian): define the Gaussian as a Schwartz function in 1D Define the Gaussian function `x ↦ exp (-x^2)` as a `SchwartzMap` in the one-dimensional case. The proof establishes the Schwartz decay conditions by showing that polynomially weighted expressions of the form `(1 + x^2)^m * exp (-x^2)` are bounded. This allows the Gaussian to be packaged using the `SchwartzMap` API. During the implementation a few adjustments were required to match the current Mathlib API. In particular: * replace the non-existent `IsBigO.mul_right` with `IsBigO.of_bound` applied to the full product `(1 + x^2)^m * exp (-x^2)` * fix `mem_cocompact` usage by replacing `(hh_tendsto.eventually ...).mem_cocompact` with `mem_cocompact.mp (hh_tendsto ...)` * adjust the `hb_bound` step using `gcongr` with exact bounds so that both goals close * remove the unused declaration `hf_nonpos` * register the required import in `Mathlib.lean` This implements the one-dimensional case mentioned in the issue. The generalization to Gaussians associated with arbitrary positive-definite bilinear forms can be added in a follow-up PR. Closes #33072	t-analysis new-contributor	235/0	Mathlib.lean,Mathlib/Analysis/SpecialFunctions/Gaussian/SchwartzMap.lean	2	3	['github-actions']	nobody	45-74359 1 month ago	unknown	unknown
35684	spitters author:spitters	feat(CategoryTheory/MarkovCategory): Kleisli PMF is a Markov category	Add `Mathlib/CategoryTheory/MarkovCategory/KleisliPMF.lean` showing that `KleisliCat PMF` is a `MarkovCategory`. Uses `Prod` as tensor and `PUnit` as unit; reuses Mathlib's existing `KleisliCat`, `LawfulMonad PMF`, and `MarkovCategory` infrastructure. Builds the full instance stack: MonoidalCategory → BraidedCategory → SymmetricCategory → CopyDiscardCategory → MarkovCategory --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-category-theory new-contributor awaiting-author merge-conflict	323/1	Mathlib.lean,Mathlib/CategoryTheory/MarkovCategory/KleisliPMF.lean,Mathlib/Tactic/Linter/DirectoryDependency.lean	3	6	['dagurtomas', 'github-actions', 'mathlib-merge-conflicts', 'spitters']	nobody	42-32987 1 month ago	54-65232 54 days ago	2-31794 2 days
36503	Mrigna01 author:Mrigna01	Add false theorem test file	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor	135/0	Mathlib/FalseBench/FalseTheorems.lean	1	3	['github-actions']	nobody	41-56269 1 month ago	unknown	unknown
14603	awueth author:awueth	feat: degree is invariant under graph isomorphism	--- Mathlib has the definition `SimpleGraph.Iso.mapNeighborSet` which is an equivalence between neighbor sets induced by an isomorphism. Would it be beneficial to add the same equivalence for `neighborFinset`? [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	WIP t-combinatorics new-contributor	24/0	Mathlib/Combinatorics/SimpleGraph/Map/Finite.lean	1	12	['SnirBroshi', 'awueth', 'github-actions', 'jcommelin', 'kim-em', 'urkud']	nobody	41-37667 1 month ago	unknown	unknown
33599	nielstron author:nielstron	feat(Computability/ContextFreeGrammar): closure under union	--- This PR picks up https://github.com/leanprover-community/mathlib4/pull/13514 and resolves the outstanding errors. - [ ] depends on: #33592 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	blocked-by-other-PR t-computability new-contributor	498/0	Mathlib/Computability/ContextFreeGrammar.lean	1	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	41-21104 1 month ago	96-29963 96 days ago	10-63563 10 days
9605	davikrehalt author:davikrehalt	feat(Data/Finset & List): Add Lemmas for Sorting and Filtering	This PR includes several useful lemmas to the Data/Finset and Data/List modules in Lean's mathlib: 1. `toFinset_filter` (List): Shows that filtering commutes with toFinset. 2. `toFinset_is_singleton_implies_replicate` (List): Shows a list with a singleton toFinset is a List.replicate. 3. `filter_sort_commute` (Finset): Sorting and filtering can be interchanged in Finsets. 4. `Sorted.filter` (List): A sorted list stays sorted after filtering. 5. `Sorted.append_largest` (List): Appending the largest element keeps a list sorted. 6. `sort_monotone_map` (Finset): Relates sorting of a Finset after mapping to sorting of a list. 7. `sort_insert_largest` (Finset): Sorting a Finset with an inserted largest element. 8. `sort_range` (Finset): Sorting a range in a Finset equals the corresponding range list. 9. ~~`filter_eval_true` (List): Filtering a list with a predicate always true keeps the list unchanged.~~ 10. ~~`filter_eval_false` (List): Filtering with an always-false predicate gives an empty list.~~ 11. ~~`pairwise_concat` (List): Iff condition for Pairwise relation in concatenated lists (similar to pairwise_join).~~ 12. `list_map_toFinset` (Finset): toFinset commutes with map under injection --- - [x] depends on: #15952 This is my first PR to mathlib, so I'm not too familiar with etiquette's and more specifically there are two proofs in the PR which uses aesop, and I am not sure if it's frowned upon. I kept the aesop in there for now as I couldn't construct very short proofs otherwise. The sort_range function proof was suggested in https://leanprover.zulipchat.com/#narrow/stream/113489-new-members/topic/Computing.20Finset.20sort.20of.20Finset.20range/near/410346731 by Ruben Van de Velde. Thanks for your time for improving this PR.	please-adopt t-data new-contributor merge-conflict awaiting-author	71/0	Mathlib/Data/Finset/Basic.lean,Mathlib/Data/Finset/Image.lean,Mathlib/Data/Finset/Sort.lean,Mathlib/Data/List/Sort.lean	4	30	['YaelDillies', 'davikrehalt', 'eric-wieser', 'github-actions', 'jcommelin', 'urkud', 'vihdzp']	nobody	41-20560 1 month ago	unknown	unknown
36529	idontgetoutmuch author:idontgetoutmuch	Connection 1 form scribbles	Some thoughts on connection 1-forms - not meant to be ever merged but here for convenience of discussion	new-contributor t-differential-geometry	496/52	Mathlib/Analysis/ODE/PicardLindelof.lean,Mathlib/Geometry/Manifold/Algebra/FundamentalVectorField.lean,Mathlib/Geometry/Manifold/IntegralCurve/Compact.lean,Mathlib/Geometry/Manifold/IntegralCurve/ExistUnique.lean,Mathlib/Order/Filter/Prod.lean	5	2	['github-actions']	nobody	40-10042 1 month ago	unknown	unknown
15720	znssong author:znssong	feat(SimpleGraph): The Bondy-Chvátal theorem	The proof of the Bondy-Chvátal theorem, with Dirac's theorem and Ore's theorem as its corollary. - [x] depends on: #15536 - [ ] depends on: #15711 - [ ] depends on: #15578	merge-conflict blocked-by-other-PR t-combinatorics new-contributor	903/3	Mathlib.lean,Mathlib/Combinatorics/SimpleGraph/BondyChvatal.lean,Mathlib/Combinatorics/SimpleGraph/Finite.lean,Mathlib/Combinatorics/SimpleGraph/Hamiltonian.lean,Mathlib/Combinatorics/SimpleGraph/Path.lean,Mathlib/Combinatorics/SimpleGraph/Walk.lean,Mathlib/Dynamics/FixedPoints/Basic.lean,Mathlib/Dynamics/FixedPoints/Increasing.lean	8	3	['github-actions', 'grunweg']	nobody	38-81946 1 month ago	unknown	unknown
22314	shetzl author:shetzl	feat: add leftmost derivations for context-free grammars	Leftmost derivations are often easier to reason about than arbitrary derivations. This PR adds leftmost variants of Rewrites, Produces and Derives to the existing definition of context-free grammars and proves that a string of terminals can be derived iff it can be leftmost derived. Co-authored-by: Tobias Leichtfried --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-computability awaiting-author new-contributor	383/0	Mathlib.lean,Mathlib/Computability/LeftmostDerivation.lean	2	55	['YaelDillies', 'github-actions', 'madvorak', 'mathlib4-merge-conflict-bot', 'shetzl']	nobody	38-81910 1 month ago	unknown	unknown
31610	rudynicolop author:rudynicolop	feat(Computability/NFA): Kleene star closure for Regular Languages via NFA	This PR constructs a Kleene star closure for non-epsilon NFAs, and proves that regular languages are closed under Kleene star. The NFA construction is `NFA.kstar`. The main theorems are: - `NFA.accepts_kstar`: demonstrates that `M.kstar` accepts the Kleene star closure of the language of `M`. - `IsRegular.kstar`: demonstrates that regular languages are closed under Kleene star. There is an onging zulip discussion about regular languages in Mathlib: https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Regular.20languages.3A.20the.20review.20queue/with/553759136 This discussion is also tracked at #24205. Furthermore, the construction and proofs in this PR are heavily inspired by @TpmKranz from his #15651. #15651 supersedes this PR, so if it is accepted then this PR is not needed. --- - [x] depends on: #31038 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-computability new-contributor awaiting-author awaiting-CI	405/7	Mathlib/Computability/NFA.lean	1	16	['YaelDillies', 'ctchou', 'github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	38-81809 1 month ago	97-74191 97 days ago	43-73349 43 days
30872	rudynicolop author:rudynicolop	feat(Computability/NFA): NFA closure under concatenation	This PR proves that regular languages are closed under concatenation via a direct construction on `NFA`s without `εNFA` nor ε-transitions. The main new definitions and results include: - `M1.concat M2`, the concatenation of `NFA`s `M1` and `M2`, a direct construction without ε-transitions. - Theorem `accepts_concat : (M1.concat M2).accepts = M1.accepts * M2.accepts`, showing the correctness of the construction. - Theorem `IsRegular.mul`, showing that regular languages are closed under concatenation. --- - [x] depends on: #31038 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-computability new-contributor awaiting-author	104/7	Mathlib/Computability/NFA.lean	1	67	['YaelDillies', 'ctchou', 'eric-wieser', 'github-actions', 'lambda-fairy', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'rudynicolop']	nobody	38-81789 1 month ago	82-70446 82 days ago	59-48116 59 days
35672	dennj author:dennj	feat(RingTheory/Polynomial/Cyclotomic): vanishing sums and fiber equidistribution at primitive roots	## Summary Building on `sum_eq_zero_iff_forall_eq` from #34592, this PR adds: - `cyclotomic_prime_coeff_eq_one`: for prime `p`, all coefficients of `cyclotomic p R` equal `1`. - `eq_nsmul_cyclotomic_of_nonneg_coeff`: a nonneg-coefficient polynomial vanishing at a primitive root is a positive scalar multiple of the cyclotomic polynomial. - `card_fiber_eq_card_div`: if a function `d : A → ZMod p` satisfies `∑ ζ^(d a) = 0`, then every fiber has cardinality `\|A\| / p`. These results are useful for combinatorial applications involving exponential sums and equidistribution over cyclic groups. Theorems imported from: https://github.com/Latinum-Agentic-Commerce/AlgebraicDesignTheory	t-ring-theory new-contributor awaiting-author	101/1	Mathlib/RingTheory/Polynomial/Cyclotomic/Basic.lean,Mathlib/RingTheory/Polynomial/Cyclotomic/Roots.lean	2	5	['github-actions', 'grunweg', 'ocfnash']	ocfnash assignee:ocfnash	37-1512 1 month ago	48-79252 48 days ago	9-45040 9 days
34713	dennj author:dennj	feat(Probability/Markov): stationary distributions for stochastic matrices	This PR proves that every row-stochastic matrix on a finite nonempty state space has a stationary distribution in the standard simplex. Main additions to `Mathlib/Probability/Markov/Stationary.lean`: - `IsStationary`: A distribution μ is stationary for matrix P if μ ᵥ* P = μ - `cesaroAverage`: Cesàro average of iterates of a vector under a matrix - `Matrix.rowStochastic.exists_stationary_distribution`: existence theorem The proof uses Cesàro averaging: start with uniform distribution, form averages, extract convergent subsequence by compactness, show limit is stationary via L¹ non-expansiveness. Also adds `vecMul_mem_stdSimplex` to `Stochastic.lean`: multiplying a probability vector by a row-stochastic matrix preserves simplex membership.	t-algebra new-contributor awaiting-author label:t-algebra$	231/0	Mathlib.lean,Mathlib/LinearAlgebra/Matrix/Stochastic.lean,Mathlib/Probability/Markov/Stationary.lean	3	12	['dennj', 'dupuisf', 'github-actions', 'grunweg', 'j-loreaux', 'mathlib-merge-conflicts', 'riccardobrasca']	nobody	37-1363 1 month ago	54-43067 54 days ago	10-31585 10 days
36587	yhx-12243 author:yhx-12243	feat(Algebra/GCDMonoid): Distributive lattice structure for Associates in GCDMonoid	Add a distributive lattice structure for `Associates α` in `GCDMonoid`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra new-contributor label:t-algebra$	61/3	Mathlib.lean,Mathlib/Algebra/GCDMonoid/Basic.lean,Mathlib/Algebra/GCDMonoid/DistribLattice.lean	3	2	['github-actions']	nobody	37-1166 1 month ago	unknown	unknown
36323	SproutSeeds author:SproutSeeds	feat(Inversion): discontinuity and center/global fderiv formulas	Part of #5939 Adds the discontinuity-at-center lemma for inversion and derives the center/global `fderiv` formulas from it. This draft currently builds on the preceding cobounded-tendsto lemma from #36313 while that earlier slice is under review. Scope is limited to `Mathlib/Geometry/Euclidean/Inversion/Calculus.lean`. Tools used: Codex 5.3 extra high --- Happy to adjust naming, placement, or proof style based on maintainer preference.	t-euclidean-geometry new-contributor LLM-generated	65/0	Mathlib/Geometry/Euclidean/Inversion/Basic.lean,Mathlib/Geometry/Euclidean/Inversion/Calculus.lean	2	2	['github-actions']	nobody	37-1107 1 month ago	unknown	unknown
36387	FrankieeW author:FrankieeW	feat(NumberTheory/QuadraticField): parameter uniqueness for quadratic fields	- [ ] depends on: #36347 ## Summary Prove that every quadratic field `ℚ(√d)` can be normalized to have a squarefree integer parameter, and that this parameter is unique. ## Main Results - `Qsqrtd.rescale`: rescaling isomorphism `ℚ(√d) ≃ₐ[ℚ] ℚ(√(a²d))` for `a ≠ 0` - `Qsqrtd_iso_int_param`: every `ℚ(√d)` is isomorphic to one with an integer parameter - `Qsqrtd_iso_squarefree_int_param`: every `ℚ(√d)` is isomorphic to one with a squarefree integer parameter - `Qsqrtd.param_unique`: if `ℚ(√d₁) ≃ₐ[ℚ] ℚ(√d₂)` with both `d₁, d₂` squarefree and `≠ 1`, then `d₁ = d₂` ## Helper Lemmas - `squarefree_eq_of_rat_sq_mul`: if `d₁ = d₂ · r²` with both squarefree, then `d₁ = d₂` - `int_dvd_of_ratio_square`: if `d₁/d₂` is a rational square and `d₂` is squarefree, then `d₂ ∣ d₁` - `not_isSquare_neg_one_rat`: `-1` is not a square in `ℚ` ---	WIP t-number-theory blocked-by-other-PR new-contributor large-import LLM-generated	400/0	Mathlib.lean,Mathlib/Algebra/QuadraticAlgebra/Defs.lean,Mathlib/Algebra/Squarefree/Basic.lean,Mathlib/NumberTheory/QuadraticField/Basic.lean	4	4	['FrankieeW', 'github-actions', 'mathlib-dependent-issues']	nobody	36-75866 1 month ago	unknown	unknown
35651	sun123zxy author:sun123zxy	feat(Mathlib/RingTheory/Ideal/Cotangent): `Submodule.map` definition of cotangent spaces	This PR adds an alternative definition of the cotangent space as an image under the R-module quotient map. --- Split from PR #33247 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-ring-theory new-contributor awaiting-author	32/18	Mathlib/RingTheory/Ideal/Cotangent.lean,Mathlib/RingTheory/Ideal/Quotient/Operations.lean	2	20	['chrisflav', 'erdOne', 'github-actions', 'mathlib-merge-conflicts', 'sun123zxy']	chrisflav assignee:chrisflav	36-73749 1 month ago	36-76554 36 days ago	16-11870 16 days
36757	alok author:alok	feat(Order/Filter): add Filter.IsFree and Filter.IsNonprincipal	## Summary Adds two filter predicates and their basic API: - `Filter.IsFree`: no point belongs to every set (`f.ker = ∅`), equivalently `f ≤ cofinite` - `Filter.IsNonprincipal`: not equal to `𝓟 s` for any set `s` Every free `NeBot` filter is non-principal (`IsFree.isNonprincipal`), but the converse fails for general filters (e.g. `𝓝 x` in a non-discrete T₁ space is non-principal but not free). For ultrafilters the two notions coincide (`Ultrafilter.isNonprincipal_iff_isFree`). On finite types, no `NeBot` filter is free (`not_isFree_of_neBot`). ## Test plan - [x] `lake build Mathlib.Order.Filter.Cofinite` passes - [x] `lake build Mathlib.Order.Filter.Ultrafilter.Basic` passes 🤖 Generated with [Claude Code](https://claude.com/claude-code)	t-order new-contributor	98/1	Mathlib/Order/Filter/Cofinite.lean,Mathlib/Order/Filter/Ultrafilter/Basic.lean	2	2	['github-actions']	nobody	36-42080 1 month ago	unknown	unknown
35058	GrigorenkoPV author:GrigorenkoPV	chore: move tendsto_{floor,ceil}_at{Top,Bot}	Moves: - Topology.Algebra.Order.Floor.tendsto_floor_atTop -> Order.Filter.AtTopBot.Floor.tendsto_floor_atTop - Topology.Algebra.Order.Floor.tendsto_floor_atBot -> Order.Filter.AtTopBot.Floor.tendsto_floor_atBot - Topology.Algebra.Order.Floor.tendsto_ceil_atTop -> Order.Filter.AtTopBot.Floor.tendsto_ceil_atTop - Topology.Algebra.Order.Floor.tendsto_ceil_atBot -> Order.Filter.AtTopBot.Floor.tendsto_ceil_atBot --- Tracked in #7987 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor large-import awaiting-author	22/25	Mathlib/Order/Filter/AtTopBot/Floor.lean,Mathlib/Topology/Algebra/Order/Floor.lean	2	3	['GrigorenkoPV', 'github-actions', 'j-loreaux']	nobody	35-86215 1 month ago	42-59989 42 days ago	27-45743 27 days
34876	GrigorenkoPV author:GrigorenkoPV	feat(Tactic/AssumptionQuestion): add `assumption?` tactic	--- As requested in #10361 TODO: maybe add some tests? [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-meta new-contributor awaiting-author	85/0	Mathlib.lean,Mathlib/Tactic.lean,Mathlib/Tactic/AssumptionQuestion.lean,Mathlib/Tactic/Common.lean,MathlibTest/AssumptionQuestion.lean,scripts/noshake.json	6	5	['GrigorenkoPV', 'SnirBroshi', 'github-actions', 'joneugster']	joneugster assignee:joneugster	35-85664 1 month ago	75-218 74 days ago	0-79222 22 hours
34814	GrigorenkoPV author:GrigorenkoPV	feat(Tactic/ClearUnneeded): add `clear_unneeded` tactic	--- The simplest version suggested in https://github.com/leanprover-community/mathlib4/issues/25319 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-meta new-contributor please-merge-master awaiting-author	94/0	Mathlib.lean,Mathlib/Tactic.lean,Mathlib/Tactic/ClearUnneeded.lean,Mathlib/Tactic/Common.lean,MathlibTest/ClearUnneeded.lean,scripts/noshake.json	6	12	['BoltonBailey', 'GrigorenkoPV', 'github-actions', 'joneugster']	joneugster assignee:joneugster	35-85515 1 month ago	75-2028 75 days ago	2-13297 2 days
34853	GrigorenkoPV author:GrigorenkoPV	feat(Combinatorics/Enumerative/Catalan): ratio of subsequent Catalan numbers	--- Should I split this into 2 PRs? Otherwise it'll get squashed & be less concise. UPD: ok, I've opened #34854 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor	304/194	Mathlib.lean,Mathlib/Combinatorics/Enumerative/Catalan.lean,Mathlib/Combinatorics/Enumerative/Catalan/Basic.lean,Mathlib/Combinatorics/Enumerative/Catalan/Ratio.lean,Mathlib/Combinatorics/Enumerative/Catalan/Tree.lean,Mathlib/Combinatorics/Enumerative/DyckWord.lean,Mathlib/RingTheory/PowerSeries/Catalan.lean	7	5	['github-actions', 'mathlib-merge-conflicts', 'vihdzp']	nobody	35-84838 1 month ago	74-86085 74 days ago	1-61543 1 day
35738	GrigorenkoPV author:GrigorenkoPV	perf: remove some `aesop`s and `grind`s	--- Needs benchmarking. After that I can split it into several smaller portions, if needed. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor awaiting-author	236/92	Mathlib/Data/Finset/Card.lean,Mathlib/Data/Rel.lean,Mathlib/Data/Set/Lattice/Image.lean,Mathlib/Data/Set/Prod.lean,Mathlib/Logic/Equiv/Prod.lean,Mathlib/Order/Interval/Finset/Basic.lean,Mathlib/Order/KrullDimension.lean,Mathlib/Order/SupIndep.lean	8	7	['github-actions', 'mathlib-merge-conflicts', 'themathqueen', 'vihdzp']	nobody	35-73073 1 month ago	56-14666 56 days ago	0-42305 11 hours
31092	FlAmmmmING author:FlAmmmmING	feat(Algebra/Group/ForwardDiff.lean): Add theorem `sum_shift_eq_fwdDiff_iter`.	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra new-contributor delegated label:t-algebra$	17/1	Mathlib/Algebra/Group/ForwardDiff.lean	1	20	['BeibeiX0', 'FlAmmmmING', 'Ruben-VandeVelde', 'dagurtomas', 'github-actions', 'jcommelin', 'mathlib-bors', 'mathlib4-merge-conflict-bot']	nobody	34-79969 1 month ago	90-1349 90 days ago	54-13842 54 days
32608	PrParadoxy author:PrParadoxy	feat(LinearAlgebra/PiTensorProduct): API for PiTensorProducts indexed by sets	This PR addresses a TODO item in LinearAlgebra/PiTensorProduct.lean: * API for the various ways ι can be split into subsets; connect this with the binary tensor product -- specifically by describing tensors of type ⨂ (i : S), M i, for S : Set ι. Our primary motivation is to formalise the notion of "restricted tensor products". This will be the content of a follow-up PR. Beyond that, the Set API is natural in contexts where the index type has an independent interpretation. An example is quantum physics, where ι ranges over distinguishable degrees of freedom, and where its is common practice to annotate objects by the set of indices they are defined on. --- Stub file with preliminary definition of the restricted tensor product as a direct limit of tensors indexed by finite subsets of an index type: https://github.com/PrParadoxy/mathlib4/blob/restricted-stub/Mathlib/LinearAlgebra/PiTensorProduct/Restricted.lean --- - [x] depends on: #32598 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor awaiting-zulip t-algebra label:t-algebra$	300/2	Mathlib.lean,Mathlib/LinearAlgebra/PiTensorProduct.lean,Mathlib/LinearAlgebra/PiTensorProduct/Set.lean	3	28	['PrParadoxy', 'dagurtomas', 'eric-wieser', 'github-actions', 'goliath-klein', 'leanprover-radar', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	34-79942 1 month ago	120-79133 120 days ago	10-64694 10 days
32745	LTolDe author:LTolDe	feat(Topology/Algebra): add MulActionConst.lean	add Topology/Algebra/MulActionConst.lean introduce class `ContinuousSMulConst` for a scalar multiplication that is continuous in the first argument, in analogy to `ContinuousConstSMul` define `MulAction.ball x U` as the set `U • {x}` given `[SMul G X] (x : X) (U : Set G)` The lemmas shown here will be useful to prove the Effros Theorem, see [zulip](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Effros.20Theorem/with/558712441). --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-author new-contributor t-topology	117/0	Mathlib.lean,Mathlib/Topology/Algebra/MulActionConst.lean	2	8	['LTolDe', 'github-actions', 'urkud']	nobody	34-79916 1 month ago	99-66260 99 days ago	16-30636 16 days
35652	dennj author:dennj	feat(LinearAlgebra/Matrix): add `Matrix.mul_eq_smul_one_symm`	## Summary - Add `Matrix.mul_eq_smul_one_symm`: if `M * N = c • 1` and `det M ≠ 0`, then `N * M = c • 1` - A scalar generalisation of `mul_eq_one_symm` (the `c = 1` case) to arbitrary scalars, requiring `IsDomain` and `det M ≠ 0` - The proof uses the adjugate identity `adjugate M * M = det M • 1` to derive `det M • (N * M) = det M • (c • 1)`, then cancels `det M` via `mul_left_cancel₀` Theorem imported from: https://github.com/Latinum-Agentic-Commerce/AlgebraicDesignTheory	t-algebra new-contributor awaiting-author LLM-generated label:t-algebra$	28/0	Mathlib/LinearAlgebra/Matrix/NonsingularInverse.lean	1	4	['dagurtomas', 'eric-wieser', 'github-actions', 'grunweg']	nobody	34-79793 1 month ago	41-817 41 days ago	17-71608 17 days
36119	Ruizsolveall author:Ruizsolveall	feat(Topology/Covering): fundamental group of the circle is ℤ	- Proves that the fundamental group of the circle `π₁(S¹, 0)` is isomorphic to `ℤ`, via covering space theory. - Constructs the winding number map `nLoop : ℤ → Path 0 0` on `AddCircle 1`, and proves it is surjective (`nLoop_surjective`), injective (`nLoop_homotopic_iff`), and additive (`nLoop_add`). - Assembles these into the group isomorphism `windingNumberIso : Multiplicative ℤ ≃* FundamentalGroup (AddCircle 1) 0`. ## Approach Uses the covering map `ℝ → AddCircle 1` and unique path lifting to establish the bijection between homotopy classes of loops and integers (winding numbers). Homotopy invariance of lifted endpoints gives injectivity; surjectivity follows from lifting arbitrary loops. Additivity uses path concatenation of lifts in the simply connected total space `ℝ`. ## AI disclosure I used Claude (Anthropic) to write the PR description, code comments, and to help refine code style. The proof strategy and all Lean code are my own. I understand and can vouch for all the code in this PR.	t-topology new-contributor awaiting-author LLM-generated	236/0	Mathlib.lean,Mathlib/Topology/Covering/FundamentalGroupCircle.lean	2	26	['Ruizsolveall', 'SnirBroshi', 'b-mehta', 'dagurtomas', 'github-actions', 'grunweg', 'vihdzp']	nobody	34-79663 1 month ago	40-70276 40 days ago	8-29756 8 days
29713	jessealama author:jessealama	feat(Algebra/Homology): add Euler–Poincaré formula	This PR builds on the generalized Euler characteristic framework from #31121 to prove the Euler-Poincaré formula for chain complexes. PR #31121 defines the Euler characteristic for general homological complexes. This PR specializes those definitions to ℤ-indexed chain complexes and proves the main Euler-Poincaré theorem. ### Main result (in `EulerPoincare.lean`) * `ChainComplex.eulerChar_eq_homologyEulerChar`: For ℤ-indexed bounded chain complexes of finite-dimensional modules over a division ring, the alternating sum of chain dimensions equals the alternating sum of homology dimensions. ### Supporting lemmas The file also provides dimension lemmas generalized to arbitrary `HomologicalComplex (ModuleCat k) c` (not just ℤ-indexed chain complexes): * `HomologicalComplex.dFrom_zero_range` / `dTo_zero_range`: zero range when the target/source object is zero * `HomologicalComplex.dFrom_range_finrank_eq_d` / `dTo_range_finrank_eq_d`: range of `dFrom`/`dTo` has the same dimension as the underlying differential * `HomologicalComplex.range_dTo_le_ker_dFrom`: range of `dTo` is contained in the kernel of `dFrom` --- Builds on: #31121 Related to: #29639, #29643, #29646	awaiting-author t-algebra new-contributor label:t-algebra$	282/0	Mathlib.lean,Mathlib/Algebra/BigOperators/Intervals.lean,Mathlib/Algebra/Homology/EulerPoincare.lean	3	25	['github-actions', 'jessealama', 'joelriou', 'kim-em', 'mathlib-merge-conflicts', 'mathlib4-merge-conflict-bot']	nobody	34-62080 1 month ago	179-25915 179 days ago	35-25302 35 days
36487	samueloettl author:samueloettl	feat(Dynamics): Ergodicity characterization	--- - [ ] depends on: #35402 - [x] depends on: #35451 This is a work in progress for a characterization of ergodicity via a Birkhoff Average. Coarse Feedback is very encouraged. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	WIP new-contributor large-import blocked-by-other-PR	421/1	Mathlib/Dynamics/Ergodic/Function.lean,Mathlib/Dynamics/Ergodic/OnAverageIndependent.lean,Mathlib/Topology/MetricSpace/Pseudo/Basic.lean	3	3	['github-actions', 'mathlib-dependent-issues']	nobody	33-79151 1 month ago	unknown	unknown
35951	parabamoghv author:parabamoghv	feat(CategoryTheory/Monoidal): evaluation coevaluation isomorphisms	This PR adds four features to rigid categories: 1. `coevaluation_evaluation` and `evaluation_coevaluation` as isomorphism equalities: Using `IsIso` instances for the `evaluation` and `coevaluation` morphisms, we promote the morphism equalities to isomorphism equalities. 2. `ExactPairing Y X` from `ExactPairing X Y`: Using an exact pairing and `IsIso` instances for both `evaluation` and `coevaluation`, we swap the exact pairing by inverting the evaluation and coevaluation morphisms. Any suggestions for the definition name are welcome. Right now it is `ExactPairing.Symm`. The second choice was `ExactPairing.Swap`. 3. `HasLeftDual X` from `HasRightDual X`: Using a `HasRightDual X` instance and relevant `IsIso` instances, we construct a left dual. Similar construction for the other way. 4. `LeftDual` isomorphic to `RightDual`: Using relevant `IsIso` instances, we provide the isomorphism from the left dual of an object to the right dual. This can be achieved in two ways: either by using `leftDualIso` or using `rightDualIso`. We will prove in a subsequent PR that both these isomorphisms are equal. Motivation: This is part of an effort to formalize CategoricalGroups, which can be defined as right rigid groupoids. The approach is motivated by the discussion in [#34830](https://github.com/leanprover-community/mathlib4/pull/34830). Any comments or suggestions are welcome, especially about the naming. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-category-theory new-contributor awaiting-author	64/2	Mathlib/CategoryTheory/Monoidal/Rigid/Basic.lean	1	18	['dagurtomas', 'github-actions', 'joelriou', 'parabamoghv', 'robin-carlier']	robin-carlier assignee:robin-carlier	33-77073 1 month ago	33-77073 33 days ago	7-31762 7 days
36170	SproutSeeds author:SproutSeeds	feat(ContMDiff): add ContMDiff scalar-action typeclasses	Closes #5617 Following the API pattern of `ContinuousConstSMul` and `ContinuousSMul`, this PR adds a smoothness parameter `n` to `ContMDiffConstSMul` and `ContMDiffSMul`, factors the generic `ContMDiff` scalar-action API into a dedicated file, and keeps `NormedSpace` focused on the standard scalar/vector instance. It also adds the corresponding `const_smul` and `smul` lemmas (`WithinAt`, `At`, `On`, and global versions). Tools used: Codex 5.3 extra high ---	t-differential-geometry new-contributor awaiting-author LLM-generated	154/21	Mathlib.lean,Mathlib/Analysis/Complex/UpperHalfPlane/Manifold.lean,Mathlib/Geometry/Manifold/Algebra/SmoothFunctions.lean,Mathlib/Geometry/Manifold/ContMDiff/MulAction.lean,Mathlib/Geometry/Manifold/ContMDiff/NormedSpace.lean	5	22	['SproutSeeds', 'github-actions', 'grunweg', 'mathlib-bors', 'mathlib-merge-conflicts', 'sgouezel']	PatrickMassot assignee:PatrickMassot	33-34485 1 month ago	42-32980 42 days ago	4-43721 4 days
34028	floor-licker author:floor-licker	feat(SimpleGraph): add max-flow/min-cut weak duality	This PR introduces a basic s–t flow setup for undirected SimpleGraphs and proves the standard weak-duality inequality: for any feasible flow f and any s–t cut S, value f ≤ cutCapacity S. This is a small, self-contained lemma I extracted while working on larger graph-theoretic formalizations, in particular, results that will ultimately rely on a full max-flow/min-cut theorem. The full MFMC equality/existence statement is not included here. This is the weak-duality direction (∀ f S, value f ≤ cutCapacity S).	t-combinatorics new-contributor	169/0	Mathlib.lean,Mathlib/Combinatorics/SimpleGraph/Connectivity/MaxFlowMinCut.lean	2	14	['SnirBroshi', 'floor-licker', 'github-actions', 'mathlib-merge-conflicts']	kmill assignee:kmill	32-74903 1 month ago	34-51946 34 days ago	60-13439 60 days
26413	michaellee94 author:michaellee94	feat: existence of maximal solutions for ODEs meeting Picard-Lindelöf conditions	Add existence proof for maximal solution of ODE using Picard-Lindelöf and a uniqueness theorem using Grönwall's lemma. --- - [x] depends on: #26382 - [ ] depends on: #29186 - [ ] depends on: #35043 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	blocked-by-other-PR new-contributor t-analysis merge-conflict	1300/431	Mathlib.lean,Mathlib/Analysis/ODE/Basic.lean,Mathlib/Analysis/ODE/ExistUnique.lean,Mathlib/Analysis/ODE/Gronwall.lean,Mathlib/Analysis/ODE/MaximalSolution.lean,Mathlib/Analysis/ODE/PicardLindelof.lean,Mathlib/Analysis/ODE/Transform.lean,Mathlib/Geometry/Manifold/IntegralCurve/Basic.lean,Mathlib/Geometry/Manifold/IntegralCurve/ExistUnique.lean,Mathlib/Geometry/Manifold/IntegralCurve/Transform.lean,Mathlib/Geometry/Manifold/IntegralCurve/UniformTime.lean,docs/1000.yaml,docs/undergrad.yaml	13	95	['botbaki-review', 'github-actions', 'grunweg', 'leanprover-community-bot-assistant', 'mathlib-merge-conflicts', 'mathlib4-dependent-issues-bot', 'michaellee94', 'winstonyin']	nobody	32-64027 1 month ago	unknown	unknown
36825	danlyng author:danlyng	feat(MeasureTheory/Integral/IntegralEqImproper): add Iic variants of nonneg/nonpos derivative integrability and FTC-2	Add the `Iic` counterparts of the existing `Ioi` results for automatic integrability of derivatives on semi-infinite intervals and the corresponding corollaries computing the integral value. Additionally, apply minor fixes to existing docstrings. New declarations: - `integrableOn_Iic_deriv_of_nonneg` / `integrableOn_Iic_deriv_of_nonneg'` - `integrableOn_Iic_deriv_of_nonpos` / `integrableOn_Iic_deriv_of_nonpos'` - `integral_Iic_of_hasDerivAt_of_nonneg` / `integral_Iic_of_hasDerivAt_of_nonneg'` - `integral_Iic_of_hasDerivAt_of_nonpos` / `integral_Iic_of_hasDerivAt_of_nonpos'` These mirror `integrableOn_Ioi_deriv_of_nonneg`, `integrableOn_Ioi_deriv_of_nonpos`, `integral_Ioi_of_hasDerivAt_of_nonneg`, `integral_Ioi_of_hasDerivAt_of_nonpos` and their primed variants.	t-measure-probability new-contributor awaiting-author	107/9	Mathlib/MeasureTheory/Integral/IntegralEqImproper.lean	1	7	['EtienneC30', 'github-actions']	EtienneC30 assignee:EtienneC30	32-5810 1 month ago	32-5810 32 days ago	2-66204 2 days
32918	michelsol author:michelsol	feat: define `supEdist` and `supDist`	Create a new file Topology.MetricSpace.SupDistance and define the supremal distance in (extended) metric spaces. The defined `supEdist` and `supDist` will have similar theory to the already existing `infEdist` and `infDist`. The motivation is to be able to define the radius of a minimal bounding sphere as the infimum of the supDist later. [zulip discussion here](https://leanprover.zulipchat.com/#narrow/channel/116395-maths/topic/Formalizing.20Jung's.20theorem.20and.20minimal.20bounding.20spheres)	t-topology new-contributor merge-conflict	75/0	Mathlib.lean,Mathlib/Topology/MetricSpace/SupDistance.lean	2	5	['github-actions', 'mathlib4-merge-conflict-bot', 'michelsol', 'urkud']	nobody	32-3822 1 month ago	106-68782 106 days ago	21-957 21 days
33668	Citronhat author:Citronhat	feat(PMF): add lintegral formulas for PMF	This PR introduces two lemmas describing the `lintegral` of a function with respect to the measure induced by a probability mass function: - `PMF.lintegral_eq_tsum` - `PMF.lintegral_eq_sum` These are the `ℝ≥0∞` analogues of the existing Bochner `integral` formulas `integral_eq_tsum` and `integral_eq_sum`. They could be useful for reasoning about expectations and integrability. In addition, the proof of `integral_eq_sum` is simplified by deriving it directly from `integral_eq_tsum` using `tsum_fintype`.	t-measure-probability new-contributor awaiting-author merge-conflict	14/5	Mathlib/Probability/ProbabilityMassFunction/Integrals.lean	1	3	['DavidLedvinka', 'github-actions', 'mathlib-merge-conflicts']	nobody	31-51409 1 month ago	50-16504 50 days ago	55-70824 55 days
33355	0xTerencePrime author:0xTerencePrime	feat(Combinatorics/SimpleGraph/Connectivity): define vertex connectivity	This PR introduces the foundations of vertex connectivity for simple graphs, providing a counterpart to the edge connectivity theory in #32870. ### Main definitions - `SimpleGraph.IsVertexReachable`: vertices remain reachable after removing strictly fewer than `k` other vertices. - `SimpleGraph.IsVertexConnected`: a graph is `k`-vertex-connected if its order is strictly greater than `k` and any two distinct vertices are `k`-vertex-reachable. Includes basic characterizations for $k=0$ and $k=1$, along with monotonicity lemmas (`anti` and `mono`).	new-contributor t-combinatorics awaiting-author merge-conflict	199/0	Mathlib.lean,Mathlib/Combinatorics/SimpleGraph/Connectivity/VertexConnectivity.lean,Mathlib/Combinatorics/SimpleGraph/IsolateVerts.lean	3	139	['0xTerencePrime', 'SnirBroshi', 'SproutSeeds', 'YaelDillies', 'github-actions', 'mathlib-merge-conflicts', 'vihdzp']	nobody	31-51385 1 month ago	41-20698 41 days ago	35-9638 35 days
14669	Command-Master author:Command-Master	feat(Data/Nat/PartENat): add lemmas for PartENat	Add some missing lemmas for `PartENat`, as well as the additive homomorphism from it to `WithTop Int`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-author t-data new-contributor merge-conflict	90/0	Mathlib/Data/Nat/PartENat.lean	1	4	['erdOne', 'github-actions', 'mathlib-merge-conflicts', 'urkud']	nobody	30-19932 30 days ago	unknown	unknown
36719	NoneMore author:NoneMore	feat(ModelTheory): add `PartialType` for first-order theories	This PR adds the definitions of partial types over theories and over parameter sets, and proves several equivalent characterizations. --- - [ ] depends on: #36667 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	blocked-by-other-PR t-logic new-contributor	468/0	Mathlib.lean,Mathlib/ModelTheory/PartialTypes.lean,Mathlib/ModelTheory/Semantics.lean,Mathlib/ModelTheory/Syntax.lean	4	5	['NoneMore', 'github-actions', 'mathlib-dependent-issues', 'vihdzp']	nobody	28-24685 28 days ago	unknown	unknown
36347	FrankieeW author:FrankieeW	feat(NumberTheory/QuadraticField): define quadratic number fields as QuadraticAlgebra ℚ d 0	Define `Qsqrtd d` as `QuadraticAlgebra ℚ d 0`, representing the quadratic number field `ℚ(√d)`. Prove trace and norm results, show `Qsqrtd d` is a number field and a quadratic extension when `d` is not a perfect square, and prove that `ℚ(√0)` and `ℚ(√1)` are not fields. Include `IsQuadraticField` as a predicate for quadratic extensions of `ℚ`, and bridge lemmas connecting squarefree integer parameters to the non-square condition. This PR is part of a series upstreaming the [QuadraticNumberFields](https://github.com/FrankieeW/QuadraticNumberFields) project. [Zulip discussion](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/quadratic.20number.20fields) --- ### PRs - #36347 （this PR） - #36387 ---	t-number-theory new-contributor large-import awaiting-author LLM-generated	191/0	Mathlib.lean,Mathlib/Algebra/QuadraticAlgebra/Defs.lean,Mathlib/Algebra/Squarefree/Basic.lean,Mathlib/NumberTheory/QuadraticField/Basic.lean	4	25	['FrankieeW', 'eric-wieser', 'github-actions', 'riccardobrasca', 'tb65536', 'wwylele']	tb65536 assignee:tb65536	28-16116 28 days ago	37-1406 37 days ago	7-4875 7 days
36850	whocares-abt author:whocares-abt	feat(Combinatorics/SimpleGraph/Acyclic): add delete leaf from tree gives tree	Added theorem stating Deleting a leaf from a tree produces a tree.	t-combinatorics new-contributor	5/0	Mathlib/Combinatorics/SimpleGraph/Acyclic.lean	1	7	['github-actions', 'vlad902']	nobody	28-3594 28 days ago	28-2982 28 days ago	34-8422 34 days
35805	adrianmartir author:adrianmartir	feat(NumberTheory/Divisors): Add `infinite_setOf_divisors_iff`	This proves that the set of divisors `{ m \| m \| n }` of a natural number `n` is infinite if and only if `n` is zero. The first proof draft was by @Aristotle-Harmonic. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-number-theory new-contributor awaiting-author	10/0	Mathlib/NumberTheory/Divisors.lean	1	6	['adrianmartir', 'alexjbest', 'github-actions', 'tb65536']	tb65536 assignee:tb65536	27-85554 27 days ago	27-85555 27 days ago	27-10796 27 days
37161	mike1729 author:mike1729	feat(Analysis/Normed/Module): add bornology and T2 instances for WeakSpace	Register the norm bornology on `WeakSpace 𝕜 E` and prove that it coincides with the von Neumann bornology of the weak topology. ### New declarations * `WeakSpace.instBornology`: norm bornology inherited from `E`. * `WeakSpace.instT2Space`: Hausdorff via Hahn–Banach separation. * `WeakSpace.norm_topology_le_weakSpace_topology`: the weak topology is coarser than the norm topology. * `WeakSpace.isBounded_iff_isVonNBounded`: norm-boundedness equals weak von Neumann boundedness (no `[CompleteSpace E]` needed). --- - [ ] depends on: #37027 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict blocked-by-other-PR new-contributor	322/113	Mathlib.lean,Mathlib/Analysis/LocallyConvex/WeakBilin.lean,Mathlib/Analysis/LocallyConvex/WeakSpace.lean,Mathlib/Analysis/Normed/Module/WeakSpace.lean,Mathlib/Topology/Algebra/Module/WeakDual.lean,Mathlib/Topology/Algebra/Module/WeakSpace.lean	6	3	['github-actions', 'mathlib-bors', 'mathlib-dependent-issues']	nobody	27-74696 27 days ago	unknown	unknown
31590	SuccessMoses author:SuccessMoses	chore: tag `commutatorElement_def` with `simp`	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-author t-algebra new-contributor merge-conflict label:t-algebra$	1/0	Mathlib/Algebra/Group/Commutator.lean	1	3	['github-actions', 'grunweg', 'mathlib-merge-conflicts']	nobody	27-74223 27 days ago	unknown	unknown
34722	GrigorenkoPV author:GrigorenkoPV	feat(Data/Finset/RangeDistance): bound distance between elements of `Finset.range`	--- Rebase of https://github.com/leanprover-community/mathlib4/pull/26347 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-data awaiting-author	34/0	Mathlib.lean,Mathlib/Algebra/Order/Group/Unbundled/Abs.lean,Mathlib/Data/Finset/RangeDistance.lean	3	7	['GrigorenkoPV', 'Vierkantor', 'github-actions', 'joneugster', 'mathlib-splicebot', 'plp127']	pechersky assignee:pechersky	26-75001 26 days ago	26-75001 26 days ago	52-16075 52 days
36216	michaellee94 author:michaellee94	feat(CategoryTheory): characterize pullback squares via the `Over` category	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-category-theory new-contributor maintainer-merge awaiting-author	47/0	Mathlib/CategoryTheory/Limits/Shapes/Pullback/IsPullback/Basic.lean	1	18	['dagurtomas', 'github-actions', 'joelriou', 'michaellee94']	robin-carlier assignee:robin-carlier	26-66079 26 days ago	26-66079 26 days ago	2-43344 2 days
34236	homeowmorphism author:homeowmorphism	feat(GroupTheory/FinitelyPresentedGroup): add finitely presented groups	Formulation of finitely presented groups feat(GroupTheory/FinitelyPresentedGroup): add finitely presented groups We define the notion of `IsFinitelyPresented` with equivalent datatype notions, what it means for a subgroup to be finitely generated in the normal closure, and some instances of finitely presented groups. This started as an ItaLean2025 project. The related Zulip thread is here: https://leanprover.zulipchat.com/#narrow/channel/541885-ItaLean-2025/topic/Projects.3A.20Finitely.20Presented.20Groups/with/567565752. Use of AI: * Aristotle was used for giving a preliminary proof of some statements as this is my first contribution and I wanted to understand how to prove things; they have since been changed. * GPT-5.2 was used to generate some of the proof sub-statements for efficiency once the mathematical blueprints of the proofs have been worked out. * GPT-5.3 was used to rapidly refactor the code. Human review by PR author in-progress, but got to a point where it would be good to get external input. * GPT-5.4 was used to refactor the variables. Human PR author then rewrote the whole thing. --- - [x] depends on: #34580 - [x] depends on: #34624 - [x] depends on: #35033 - [x] depends on: #35029 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-group-theory new-contributor merge-conflict	305/0	Mathlib.lean,Mathlib/GroupTheory/FinitelyPresentedGroup.lean	2	72	['copilot-pull-request-reviewer', 'eric-wieser', 'github-actions', 'grunweg', 'homeowmorphism', 'kbuzzard', 'mathlib-bors', 'mathlib-dependent-issues', 'mathlib-merge-conflicts', 'tb65536']	nobody	26-41551 26 days ago	33-63142 33 days ago	0-4008 1 hour
35857	AlexeyMilovanov author:AlexeyMilovanov	feat(Logic.Equiv.BijectiveBase2): add bijective base-2 numeration	This PR introduces a formalization of the bijective base-2 numeration system. Unlike standard binary representation, bijective base-2 avoids the "leading zeros" problem, providing a strict mathematical bijection between natural numbers (`ℕ`) and lists of booleans (`List Bool`). Main additions: * `Equiv.BijectiveBase2.toBits`: Encodes `ℕ` to `List Bool`. * `Equiv.BijectiveBase2.ofBits`: Decodes `List Bool` to `ℕ`. * `equivBijectiveBase2`: The formal `ℕ ≃ List Bool` equivalence. --- Zulip: [#PR reviews > PR #35857: Bijective Base-2 Numeration](https://leanprover.zulipchat.com/#narrow/channel/144837-PR-reviews/topic/PR.20.2335857.3A.20Bijective.20Base-2.20Numeration/with/576336540) Zulip: [#batteries > Upstreaming Nat.Bits](https://leanprover.zulipchat.com/#narrow/channel/348111-batteries/topic/Upstreaming.20Nat.2EBits/with/580736051) (Note: This replaces my previously closed PR to avoid the terminology clash between "Dyadic" and dyadic rationals. The namespace and definitions have been updated accordingly). (Note: Used AI to assist with standardizing proof structures).	t-logic new-contributor LLM-generated blocked-by-batt-PR	95/0	Mathlib.lean,Mathlib/Logic/Equiv/ListNatBijective.lean	2	6	['AlexeyMilovanov', 'SnirBroshi', 'github-actions', 'joneugster']	nobody	26-13322 26 days ago	26-13372 26 days ago	27-57874 27 days
36463	AlexeyMilovanov author:AlexeyMilovanov	feat(Data.Nat.Bits): add Nat.ofBits and prove bits_injective	This PR introduces `Nat.ofBitsList` for `List Bool` and provides the missing proofs that the standard binary representation `Nat.bits` is injective (`Nat.bits_injective`) and possesses a right inverse for normalized lists (`Nat.bits_ofBitsList`). `ofBitsList` is implemented as an `abbrev` using `foldr` (keeping it transparent to tactics like `simp`). It serves as the exact left inverse to `bits`. Furthermore, `bits_ofBitsList` establishes that `bits` and `ofBitsList` form a bijection between `ℕ` and the set of lists with no trailing `false` values. This avoids the name collision with `Nat.ofBits` from `Batteries` and aligns with previous Zulip discussions (see [here](https://leanprover.zulipchat.com/#narrow/channel/144837-PR-reviews/topic/PR.20.2335857.3A.20Bijective.20Base-2.20Numeration)) regarding the utility of having a complete list-based API for `Nat.bits` in the library. CC: @linesthatinterlace - Adds `Nat.ofBitsList` (as an `abbrev`) - Adds `Nat.ofBitsList_bits` (left inverse property) - Adds `Nat.bits_injective` - Adds `Nat.ofBitsList_eq_zero_iff` (helper lemma for lists without trailing zeros) - Adds `Nat.bits_ofBitsList` (right inverse property) --- Zulip: [#PR reviews > PR #35857: Bijective Base-2 Numeration](https://leanprover.zulipchat.com/#narrow/channel/144837-PR-reviews/topic/PR.20.2335857.3A.20Bijective.20Base-2.20Numeration/with/576336540) Zulip: [#batteries > Upstreaming Nat.Bits](https://leanprover.zulipchat.com/#narrow/channel/348111-batteries/topic/Upstreaming.20Nat.2EBits/with/580736051)	t-data new-contributor awaiting-author blocked-by-batt-PR	68/1	Mathlib/Data/Nat/Bits.lean	1	5	['github-actions', 'joneugster', 'linesthatinterlace']	nobody	26-13315 26 days ago	32-81427 32 days ago	9-52446 9 days
36274	JTylM author:JTylM	feat(Combinatorics/SimpleGraph/Matching): implemented the matchingNumber of a graph	--- - [ ] depends on: #36406 - [ ] depends on: #32555 I implemented the matchingNumber as described in the issue and proved some statements including showing that there exists a matching achieving the matchingNumber. matchingNumber is increasing under injective maps matchingNumber is equal under isomorphisms matchingNumber of a matching is the cardinality of the matching This is my first PR and i had some trouble with some of the proofs, especially with the proof for matchingNumber.isAttained. So any suggestions on how to make the proofs shorter would be welcome. Also i was not sure about the naming of some of the theorems so i would apprechiate feedback here as well.	new-contributor t-combinatorics blocked-by-other-PR	292/2	Mathlib/Combinatorics/SimpleGraph/Matching.lean	1	39	['JTylM', 'SnirBroshi', 'SproutSeeds', 'github-actions', 'mathlib-dependent-issues', 'vlad902']	nobody	26-2333 26 days ago	34-3979 34 days ago	8-57371 8 days
35473	mike1729 author:mike1729	feat(Analysis/Normed/Module): Schauder bases, basic sequences, and the Eberlein–Šmulian theorem	This PR develops the theory of Schauder bases and basic sequences in Banach spaces, culminating in a proof of the Eberlein–Šmulian theorem: in a Banach space, a weakly countably compact set is weakly compact (and weakly sequentially compact). Note: This PR is too large to review in one go. It will be split into smaller parts and merged incrementally. The first part is already under review: The proof follows the basic-sequence approach of Pełczyński, as presented in Albiac–Kalton Topics in Banach Space Theory (2016). The main line of argument is: 1. Define generalized Schauder bases (indexed by arbitrary types with a summation filter) and the classical sequential Schauder basis as a special case. 2. Introduce basic sequences and their characterization via the Grünblum condition. 3. Prove the selection principle: extract basic sequences from sets where the weak and norm closures disagree (via a perturbation/finite-dimensional compactness argument in the dual). 4. Show that a bounded set containing no basic sequence has relatively weakly compact closure. 5. Combine these ingredients to prove both directions of the Eberlein–Šmulian theorem. ## Main definitions * `GeneralSchauderBasis β 𝕜 X L`: A Schauder basis for a normed space `X` over `𝕜`, indexed by a type `β` with a `SummationFilter L`. Unifies classical (sequential) and unconditional bases. * `BasicSequence 𝕜 X`: A bundled ℕ-indexed sequence forming a Schauder basis for its closed linear span. ## Main results * `isBasicSequence_of_Grunblum_with_bound`: A nonzero sequence satisfying the Grünblum condition is a basic sequence, with explicit basis constant bound. * `basic_sequence_selection_dual`: Extracts a basic sequence from a set that is weak-dense near 0 but norm-separated from 0. `exists_basicSequence_of_weakClosure_not_normClosure`: If 0 is in the weak closure of `S` but not its norm closure, then `S` contains a basic sequence. * `schauderBasisOfClosure`: Constructs a Schauder basis for the topological closure from a basis on a subspace. * `no_basic_sequence_implies_relatively_weakly_compact`: A bounded set with no basic sequence has weakly compact closure. * `eberlein_smulian_isSeqCompact`: A weakly countably compact set in a Banach space is weakly sequentially compact. * `eberlein_smulian`: Eberlein–Šmulian theorem. A weakly countably compact set in a Banach space is weakly compact. * `IsCompact.frechetUrysohnSpace`: Weakly compact subsets of a Banach space are Fréchet–Urysohn (angelic). ## References * [F. Albiac, N.J. Kalton, Topics in Banach Space Theory, Springer, 2016][albiac2016] * I. Singer, Bases in Banach Spaces, 1970. --- - [x] depends on: #34209 - [x] depends on: #35559 - [x] depends on: #36174 - [ ] depends on: #36849 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-analysis new-contributor blocked-by-other-PR	2691/0	Mathlib.lean,Mathlib/Analysis/Normed/Module/SchauderBasis/Basic.lean,Mathlib/Analysis/Normed/Module/SchauderBasis/BasicSequence.lean,Mathlib/Analysis/Normed/Module/SchauderBasis/BasicSequenceSelection.lean,Mathlib/Analysis/Normed/Module/SchauderBasis/Closure.lean,Mathlib/Analysis/Normed/Module/SchauderBasis/CountablyCompact.lean,Mathlib/Analysis/Normed/Module/SchauderBasis/EberleinSmulian.lean,Mathlib/Analysis/Normed/Module/SchauderBasis/NoBasicSequence.lean	8	6	['CoolRmal', 'github-actions', 'mathlib-dependent-issues', 'mike1729']	nobody	25-71928 25 days ago	unknown	unknown
36853	matthunz author:matthunz	feat(CategoryTheory/Monoidal/Braded/Traced): add `TracedCategory` class	Adds a `TracedCategory` class following [A. Joyal and R. Street and D. R. Verity, Traced monoidal categories](https://www.cambridge.org/core/journals/mathematical-proceedings-of-the-cambridge-philosophical-society/article/abs/traced-monoidal-categories/2BE85628D269D9FABAB41B6364E117C8#article): ```lean /-- A traced symmetric monoidal category. -/ class TracedCategory (C : Type u) [Category.{v} C] [MonoidalCategory.{v} C] [SymmetricCategory.{v} C] where /-- The trace operator. -/ trace : ∀ {A B : C} (W : C), (A ⊗ W ⟶ B ⊗ W) → (A ⟶ B) /-- Left tightening: sliding a morphism past the trace on the left. -/ trace_naturality_left : ∀ {A A' B : C} (W : C) (f : A' ⟶ A) (g : A ⊗ W ⟶ B ⊗ W), trace W (f ▷ W ≫ g) = f ≫ trace W g := by cat_disch /-- Right tightening: sliding a morphism past the trace on the right. -/ trace_naturality_right : ∀ {A B B' : C} (W : C) (f : A ⊗ W ⟶ B ⊗ W) (g : B ⟶ B'), trace W (f ≫ g ▷ W) = trace W f ≫ g := by cat_disch /-- Sliding: an endomorphism on the feedback wire slides past the trace. -/ trace_dinaturality : ∀ {A B W : C} (f : A ⊗ W ⟶ B ⊗ W) (h : W ⟶ W), trace W (f ≫ B ◁ h) = trace W (A ◁ h ≫ f) := by cat_disch /-- Superposing: trace commutes with left tensoring by a bystander object. -/ trace_superposing : ∀ {A B : C} (C' W : C) (f : A ⊗ W ⟶ B ⊗ W), C' ◁ trace W f = trace W ((α_ C' A W).hom ≫ C' ◁ f ≫ (α_ C' B W).inv) := by cat_disch /-- Vanishing I: trace over the tensor unit is the morphism itself (up to unitors). -/ trace_vanishing_one : ∀ {A B : C} (f : A ⊗ 𝟙_ C ⟶ B ⊗ 𝟙_ C), trace (𝟙_ C) f = (ρ_ A).inv ≫ f ≫ (ρ_ B).hom := by cat_disch /-- Vanishing II: trace over a tensor product equals iterated trace. -/ trace_vanishing_two : ∀ {A B X Y : C} (f : A ⊗ (X ⊗ Y) ⟶ B ⊗ (X ⊗ Y)), trace (X ⊗ Y) f = trace X (trace Y ((α_ A X Y).hom ≫ f ≫ (α_ B X Y).inv)) := by cat_disch /-- Yanking: the trace of the braiding is the identity. -/ trace_yanking : ∀ (W : C), trace W (β_ W W).hom = 𝟙 W := by cat_disch ``` ## Motivation `TracedCategory` can be used for denoting things like electric circuits, which require a traced symmetric monoidal category for the wire graph network. ## Future work - `instance [CompactClosedCategory C] : TracedCategory C` - possible notation such as `Tr_[W] f` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-category-theory new-contributor awaiting-author	237/0	Mathlib.lean,Mathlib/CategoryTheory/Monoidal/Braided/Traced.lean,Mathlib/CategoryTheory/Monoidal/Rigid/Traced.lean,docs/references.bib	4	4	['dagurtomas', 'github-actions', 'matthunz']	nobody	25-41139 25 days ago	33-68765 33 days ago	0-24596 6 hours
33817	FlAmmmmING author:FlAmmmmING	fix(Combinatorics/Enumerative/Schroder): fix the definition of `smallSchroder`	In the previous definition, the small Schröder numbers were defined as ```LaTeX s_0 = 1, s_1 = 1, s_2 = 1, s_3 = 3... ``` , which does not match the sequence listed in OEIS A006318. Moreover, this definition makes it difficult to correctly write the generating function for the small Schröder numbers. This PR fixes this issue. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-combinatorics large-import awaiting-author	61/39	Mathlib/Combinatorics/Enumerative/Schroder.lean	1	20	['FlAmmmmING', 'YaelDillies', 'github-actions', 'vihdzp']	YaelDillies assignee:YaelDillies	24-41251 24 days ago	27-33941 27 days ago	74-33585 74 days
34703	martinwintermath author:martinwintermath	Generalizing orthogonalBilin	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor	51/25	Mathlib/Analysis/InnerProductSpace/Orthogonal.lean,Mathlib/LinearAlgebra/QuadraticForm/Basic.lean,Mathlib/LinearAlgebra/SesquilinearForm/Basic.lean	3	1	['github-actions']	nobody	24-6316 24 days ago	unknown	unknown
34419	ster-oc author:ster-oc	feat(RCLike): add `Continuous.re` and similar	This PR adds dot notation for `re`, `im`, `conj` and `ofReal` for `Continuous`, `LipschitzWith` and `Memℓp`. Given `hf : Continuous f` it allows to use `hf.re` to express `Continuous (fun x ↦ (f x).re)`, similarly to the usual `hf.add hg`. I also can add the same features for `Summable` but I am not sure where to place them, suggestions are appreciated! --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-analysis new-contributor awaiting-author merge-conflict	186/41	Mathlib/Analysis/Normed/Group/Uniform.lean,Mathlib/Analysis/Normed/Lp/lpSpace.lean,Mathlib/Analysis/RCLike/Basic.lean	3	15	['github-actions', 'j-loreaux', 'mathlib-merge-conflicts', 'ster-oc']	j-loreaux assignee:j-loreaux	22-60784 22 days ago	56-74539 56 days ago	8-23775 8 days
35376	michaellee94 author:michaellee94	feat(Geometry/Manifold): orientable manifolds	--- - [x] depends on: #33189 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor WIP t-differential-geometry merge-conflict awaiting-author	2116/11	Mathlib.lean,Mathlib/Geometry/Manifold/Instances/MoebiusBand.lean,Mathlib/Geometry/Manifold/Instances/Real.lean,Mathlib/Geometry/Manifold/IsManifold/ExtChartAt.lean,Mathlib/Geometry/Manifold/IsManifold/InteriorBoundary.lean,Mathlib/Geometry/Manifold/Orientation.lean,Mathlib/Topology/Closure.lean	7	8	['Rida-Hamadani', 'github-actions', 'mathlib-dependent-issues', 'mathlib-merge-conflicts']	nobody	22-3239 22 days ago	unknown	unknown
30142	shalliso author:shalliso	feat(Topology/Baire): define IsNonMeagre	non-meagre sets (also known as "of the second category") are worthy of their own definition and API. This was useful to me for formalizing a result of "automatic continuity", that is, a Baire-measurable homomorphism between Polish groups must be continuous. Simply working with the negation of IsMeagre quickly became cumbersome, and non-meagre sets have an important role in the study of Polish (e.g. locally compact) groups. From https://github.com/shalliso/automatic_continuity --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology new-contributor merge-conflict awaiting-author	83/1	Mathlib/Topology/Baire/NonMeagre.lean,Mathlib/Topology/GDelta/Basic.lean	2	6	['github-actions', 'grunweg', 'mathlib4-merge-conflict-bot']	nobody	22-1646 22 days ago	unknown	unknown
37445	edwin1729 author:edwin1729	feat(Topology/Order): set of compact elements, generating basic opens contained in a `Locale.PT`, is directed	This is (2/4) PRs culminating in a proof that "Scott Topologies over Algebraic DCPOs are Sober". In this PR we prove properties of a certain set of compact elements, w.r.t a `Locale.PT`. A `Locale.PT` can be thought of as a set of `Opens`. Precisely it is a Frame homomorphism from `Opens _` to `Prop` so we are essentially choosing certain `Opens` to form our set and this set has additional properties. Namely it is a completely prime filter: if the supremum of some Opens is contained than atleast one of the Opens must be contained. Take some `Locale.PT`, `x`. In this PR, we prove that the set of compact elements generating basic opens (compact elements generate topological basis see #31662) contained in `x` is directed. This set of compact elements defined above is important in subsequent parts of the proof since it fully determines `x`. - [ ] depends on: #31662 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology blocked-by-other-PR new-contributor	296/1	Mathlib.lean,Mathlib/Topology/Order/ScottTopology.lean,Mathlib/Topology/Order/ScottTopologyDCPO.lean,docs/references.bib	4	3	['github-actions', 'mathlib-dependent-issues']	nobody	21-81006 21 days ago	unknown	unknown
35317	mkaratarakis author:mkaratarakis	feat: lemmas for the analytic part of the proof of the Gelfond–Schneider theorem (Part 5/5)	If a function `R : ℂ → ℂ` factors as `R z = (z - z₀) ^ r * R₁ z`, where `R₁` is analytic everywhere, then for any `k ≤ r`, there exists an everywhere analytic function `R₂ : ℂ → ℂ` such that the `k`-th iterated derivative of `R` is given by `deriv^[k] R z = (z - z₀) ^ (r - k) * (r! / (r - k)! * R₁ z + (z - z₀) * R₂ z)`. This lemma is necessary for the proof of the Gelfond-Schneider theorem in subsequent PRs. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-number-theory new-contributor t-analysis awaiting-author	57/0	Mathlib/Analysis/Complex/CauchyIntegral.lean	1	25	['MichaelStollBayreuth', 'github-actions', 'loefflerd', 'mkaratarakis']	loefflerd assignee:loefflerd	21-64319 21 days ago	21-64319 21 days ago	26-1122 26 days
36781	hommmmm author:hommmmm	feat(RingTheory/UniqueFactorizationDomain): UFD iff height one primes are principal	We prove that a Noetherian integral domain is a UFD if and only if every prime ideal of height one is principal (`UniqueFactorizationMonoid.iff_height_one_prime_principal`). ## New declarations * `UniqueFactorizationMonoid.exists_height_one_le_of_finite_height`: given a prime of finite height ≥ 1, there exists a height one prime contained in it. * `UniqueFactorizationMonoid.ne_bot_of_height_one`: an ideal of height one is nonzero. * `UniqueFactorizationMonoid.height_ge_one_of_prime_ne_bot`: the height of a nonzero prime ideal in a domain is at least one. * `UniqueFactorizationMonoid.height_one_prime_principal`: in a UFD, every height one prime is principal. * `UniqueFactorizationMonoid.of_height_one_prime_principal`: every height one prime being principal implies UFD (Noetherian case). * `UniqueFactorizationMonoid.iff_height_one_prime_principal`: the full iff statement. ## References See https://stacks.math.columbia.edu/tag/0AFT ## AI Disclosure This code is written without AI, then uses Claude Code with cameronfreer's [Lean4-skills](https://github.com/cameronfreer/lean4-skills) (specifically, the `review`, `refactor`, and `golf` workflow) for style changes, refactoring and golfing. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-ring-theory new-contributor large-import	102/1	Mathlib/RingTheory/UniqueFactorizationDomain/Kaplansky.lean	1	8	['Thmoas-Guan', 'chrisflav', 'github-actions', 'hommmmm', 'tb65536']	mattrobball assignee:mattrobball	21-50957 21 days ago	30-69198 30 days ago	35-15685 35 days
36886	Deep0Thinking author:Deep0Thinking	feat(Combinatorics/Enumerative/Bonferroni): add Bonferroni inequalities	This PR adds Bonferroni inequalities. Main theorems: - `Finset.indicator_biUnion_le_bonferroniIndicator_of_odd` - `Finset.bonferroniIndicator_le_indicator_biUnion_of_even` - `Finset.card_biUnion_le_bonferroniCard_of_odd` - `Finset.bonferroniCard_le_card_biUnion_of_even` Co-authored-by: Claude (Opus 4.6) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-combinatorics new-contributor	334/4	Mathlib.lean,Mathlib/Combinatorics/Enumerative/Bonferroni.lean,Mathlib/Combinatorics/Enumerative/InclusionExclusion.lean	3	4	['AlexeyMilovanov', 'Deep0Thinking', 'github-actions']	nobody	21-7869 21 days ago	32-86077 32 days ago	32-85490 32 days
37101	fsefzig author:fsefzig	feat: definition of kummer polynomials and prove that AdjoinRoot (KummerPolynomial n s) is etale	This defines the Kummer polynomial ` KummerPolynomial n s := X^n - s` over a ring R and constructs the following instances for `AdjoinRoot (KummerPolynomial n s)`: · Faithfullyflat · SmoothOfRelativeDimension 0 · Etale	t-ring-theory new-contributor awaiting-author	345/0	Mathlib.lean,Mathlib/RingTheory/AdjoinRootKummer.lean	2	24	['acmepjz', 'chrisflav', 'fsefzig', 'github-actions', 'vihdzp']	nobody	20-76669 20 days ago	unknown	unknown
32583	MJ141592 author:MJ141592	refactor(SimpleGraph): change bridges not to require the edge to be present	Remove the requirement for edges to exist in definition of isBridge, and then change the related lemmas to adjust for this, by renaming, fixing the statements and fixing the proofs, including in Acyclic. Closes #31690. --- - [x] depends on: #36802 - [x] depends on: #36804	t-combinatorics new-contributor	84/84	Mathlib/Combinatorics/SimpleGraph/Acyclic.lean,Mathlib/Combinatorics/SimpleGraph/Connectivity/Connected.lean,Mathlib/Combinatorics/SimpleGraph/Connectivity/EdgeConnectivity.lean,Mathlib/Combinatorics/SimpleGraph/Hamiltonian.lean	4	20	['MJ141592', 'SnirBroshi', 'YaelDillies', 'b-mehta', 'github-actions', 'mathlib-dependent-issues', 'mathlib-merge-conflicts', 'mathlib4-merge-conflict-bot']	nobody	20-22561 20 days ago	20-21373 20 days ago	20-38957 20 days
34487	martinwintermath author:martinwintermath	feat(LinearAlgebra/SesquilinearForm): add instances for SeparatingLeft, SeparatingRight and Nondegenerate	Add typeclass instances for `Fact B.SeparatingLeft`, `Fact B.SeparatingRight`, `Fact B.Nondegenerate`: * inferring `Fact B.flip.SeparatingLeft` from `Fact B.SeparatingRight` and vice versa * inferring `Fact B.SeparatingLeft` and `Fact B.SeparatingRight` from `Fact B.Nondegenerate` * inferring `Fact B.SeparatingLeft` and `Fact B.Nondegenerate` for `.id` and `Dual.eval` * inferring `Fact B.Nondegenerate` from `B.IsPerfPair` I also updated `PointedCone.dual_univ` to demonstrate the usefulness of these additions. Note that I needed to add an import to `Cone/Dual.lean` which somehow imports cardinals. So I needed to remove cardinals from `assert_not_exists`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra new-contributor large-import label:t-algebra$	84/16	Mathlib/Geometry/Convex/Cone/Dual.lean,Mathlib/LinearAlgebra/Dual/Lemmas.lean,Mathlib/LinearAlgebra/PerfectPairing/Basic.lean,Mathlib/LinearAlgebra/SesquilinearForm/Basic.lean	4	4	['github-actions', 'martinwintermath', 'mathlib-merge-conflicts', 'mathlib4-merge-conflict-bot']	joelriou assignee:joelriou	20-6124 20 days ago	23-73636 23 days ago	13-72716 13 days
31670	edwin1729 author:edwin1729	feat(Topology/Order): Scott Topology is Sober over Algebraic DCPO	--- [Zulip discussion](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/.3E.20Algebraic.20complete.20partial.20order.20and.20domain.20theory/with/536359313) here (2/2) PR to prove result in Stone Duality. Here we prove that Scott Topologies over Algebraic DCPOs are sober. - [ ] depends on: #31662 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology blocked-by-other-PR new-contributor	456/1	Mathlib.lean,Mathlib/Topology/Order/ScottTopology.lean,Mathlib/Topology/Order/ScottTopologyDCPO.lean,docs/references.bib	4	4	['github-actions', 'mathlib-merge-conflicts', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	19-84177 19 days ago	unknown	unknown
37556	edwin1729 author:edwin1729	feat(Topology/Order): Locale.localePointOfSpacePoint if we have a Scott Topology from an Algebraic DCPO	(3/4) in a series of PRs proving that "Scott Topologies over Algebraic DCPOs are Sober" We prove here that the unit of the adjunction from `TopCat` to `Locale` defined in `Topology/Order/Category/FrameAdjunction.lean` is a surjective mapping, under the following condition: The underlying TopologicalSpace must be a Scott Topology generated with an underlying Algebraic DCPO structure. - [ ] depends on: #37445 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology new-contributor blocked-by-other-PR	393/1	Mathlib.lean,Mathlib/Topology/Order/ScottTopology.lean,Mathlib/Topology/Order/ScottTopologyDCPO.lean,docs/references.bib	4	4	['github-actions', 'mathlib-dependent-issues']	nobody	19-81027 19 days ago	19-81028 19 days ago	0-562 9 minutes
36704	adam84-hub author:adam84-hub	chore(Function): add surjective_iff	Adds an explicit discoverable definitional lemma for `Function.Surjective`. - addresses #31745 - scope is intentionally tiny: one theorem in `Mathlib/Logic/Function/Defs.lean` AI was used for drafting; I reviewed the final code and understand it well enough to vouch for it.	t-logic new-contributor awaiting-author	4/0	Mathlib/Logic/Function/Defs.lean	1	11	['SnirBroshi', 'adam84-hub', 'github-actions', 'plp127', 'vihdzp']	nobody	19-76498 19 days ago	unknown	unknown
34054	YellPika author:YellPika	feat(Order/OmegaCompletePartialOrder): OmegaCompletePartialOrder instance for `Sigma` with basic `ωScottContinuous` lemmas	This PR adds an `OmegaCompletePartialOrder` instance for `Sigma` along with `ωScottContinuous` lemmas for basic operations (`mk`, `fst`, `snd`). Appropriate lemmas are marked with `@[fun_prop]` so that the `fun_prop` tactic can automatically deduce `ωScottContinuous` proofs for functions involving `Sigma`s. --- - [x] depends on: #33941 - [ ] depends on: #37258 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-order please-merge-master awaiting-author	172/0	Mathlib/Data/Sigma/Order.lean,Mathlib/Order/OmegaCompletePartialOrder.lean	2	28	['Vierkantor', 'YellPika', 'github-actions', 'grunweg', 'mathlib-dependent-issues', 'mathlib-merge-conflicts']	grunweg assignee:grunweg	19-73633 19 days ago	60-67828 60 days ago	16-56783 16 days
36832	KryptosAI author:KryptosAI	chore(Data/Finset/Card): rename `pred_card_le_card_erase` to `sub_one_card_le_card_erase`	## Summary The name `pred_card_le_card_erase` suggests `Nat.pred` but the statement uses `- 1` (i.e., `Nat.sub 1`). Rename to `sub_one_card_le_card_erase` to match the actual statement. A deprecated alias is added for backwards compatibility. ### Files changed - `Mathlib/Data/Finset/Card.lean` — definition renamed + deprecated alias - `Mathlib/Data/Finset/Powerset.lean` — reference updated - `Mathlib/Combinatorics/Additive/SubsetSum.lean` — reference updated - `Mathlib/Algebra/Polynomial/EraseLead.lean` — reference updated Addresses the `Finset.pred_card_le_card_erase` item in #21584. ## AI disclosure I used Claude Code to explore the codebase (finding all references to rename) and to draft the PR description. I reviewed and understand all changes — these are straightforward renames with a deprecated alias.	new-contributor	22/15	Mathlib/Algebra/Polynomial/EraseLead.lean,Mathlib/Combinatorics/Additive/SubsetSum.lean,Mathlib/Combinatorics/SetFamily/AhlswedeZhang.lean,Mathlib/Combinatorics/SetFamily/Shadow.lean,Mathlib/Data/Finset/Card.lean,Mathlib/Data/Finset/Powerset.lean,Mathlib/Data/Set/Card.lean,Mathlib/GroupTheory/Perm/Support.lean,Mathlib/RingTheory/Ideal/Operations.lean	9	5	['KryptosAI', 'Multramate', 'github-actions', 'ooovi']	nobody	19-47554 19 days ago	19-44518 19 days ago	33-49867 33 days
37585	cascone26 author:cascone26	feat: formal statements of Robin's and Lagarias' inequalities equivalent to RH	## Summary This PR adds `Mathlib/NumberTheory/LSeries/RobinInequality.lean`, which contains formal Lean 4 statements of two classical equivalences of the Riemann Hypothesis: Robin's theorem (1984): RH ↔ σ₁(n) < e^γ · n · ln(ln(n)) for all n > 5040 Lagarias' theorem (2002): RH ↔ σ₁(n) ≤ H_n + exp(H_n) · ln(H_n) for all n ≥ 1 ### New declarations - `robinBound (n : ℕ) : ℝ` — the Robin bound e^γ · n · ln(ln(n)) - `lagariasBound (n : ℕ) : ℝ` — the Lagarias bound H_n + exp(H_n) · ln(H_n) - `robin_iff_RH : RiemannHypothesis ↔ ∀ n > 5040, σ₁(n) < robinBound n` - `lagarias_iff_RH : RiemannHypothesis ↔ ∀ n ≥ 1, σ₁(n) ≤ lagariasBound n` ### Status The statements are complete and use existing Mathlib primitives: - `ArithmeticFunction.sigma` for σ₁ - `Real.eulerMascheroniConstant` for γ - `harmonic` for H_n (with ℚ → ℝ coercion) - `RiemannHypothesis` from `Mathlib.NumberTheory.LSeries.RiemannZeta` The proofs are currently `sorry`. The Robin direction (RH → inequality) requires analytic number theory following Robin's original 1984 paper. The converse uses Gronwall's theorem on superior highly composite numbers. Both are substantial Mathlib projects in their own right. This PR establishes the formal statements as a foundation for future proof work. These equivalences are not currently formalized anywhere in Mathlib. ### References - G. Robin, Grandes valeurs de la fonction somme des diviseurs et hypothèse de Riemann, J. Math. Pures Appl. 63 (1984), 187–213. - J. Lagarias, An elementary problem equivalent to the Riemann hypothesis, Amer. Math. Monthly 109 (2002), 534–543. ### Note on `sorry` I'm aware Mathlib does not merge `sorry`-laden PRs in general. I'm submitting this as a draft to: 1. Get feedback on whether the statement formulation is idiomatic 2. Establish that these statements don't already exist in Mathlib under a different name 3. Invite collaboration on completing the proofs	t-number-theory new-contributor	98/0	Mathlib/NumberTheory/LSeries/RobinInequality.lean	1	2	['github-actions']	nobody	19-35434 19 days ago	unknown	unknown
28613	espottesmith author:espottesmith	feat(Combinatorics): define undirected hypergraphs	This PR defines undirected hypergraphs: ``` @[ext] structure Hypergraph (α : Type*) where /-- The vertex set -/ vertexSet : Set α /-- The hyperedge set -/ hyperedgeSet : Set (Set α) /-- All hyperedges must be subsets of the vertex set -/ hyperedge_isSubset_vertexSet : ∀ ⦃e⦄, e ∈ hyperedgeSet → e ⊆ vertexSet ``` In addition to the main definition, some additional definitions and related lemmas are provided: - vertex adjacency - hyperedge adjacency - vertex "stars" - special cases (loops, empty hypergraphs, trivial hypergraphs, complete hypergraphs, simple hypergraphs, k-uniform hypergraphs, and d-regular hypergraphs) - (some) hypergraph cardinality - subhypergraphs, induced subhypergraphs, and partial hypergraphs This implementation is certainly bare-bones. I'm submitting this PR at this point, rather than when my developments are more fleshed out, because there has been some interest in others contributing to hypergraph formalization in mathlib. In the near future, goals include: - defining incidence matrices (i.e., conversion from `Hypergraph α` to `Matrix α (Set α) β` - coersion/generalization of graph as 2-uniform hypergraph - conversion of a hypergraph into its associated clique graph/two-section graph - constructing the dual of a hypergraph (note: on first blush, this appears somewhat challenging, given that we define hyperedges as `Set α` rather than some other type `β`) - rank and co-rank - walks, paths, cycles, etc. on hypergraphs --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-combinatorics new-contributor	378/0	Mathlib.lean,Mathlib/Combinatorics/Hypergraph/Basic.lean	2	54	['b-mehta', 'espottesmith', 'github-actions', 'jt496', 'lauramonk', 'mathlib4-merge-conflict-bot']	b-mehta assignee:b-mehta	19-23061 19 days ago	154-26371 154 days ago	76-50008 76 days
29744	espottesmith author:espottesmith	feat(Combinatorics): define directed hypergraphs	This PR defines directed hypergraphs: ``` @[ext] structure DiHypergraph (α : Type*) where /-- The vertex set -/ vertexSet : Set α /-- The edge set -/ edgeSet : Set ((Set α) × (Set α)) /-- Each edge is a pair (s, d), where s ⊆ vertexSet and d ⊆ vertexSet -/ edge_src_dst_isSubset_vertexSet' : ∀ ⦃e⦄, e ∈ edgeSet → e.1 ⊆ vertexSet ∧ e.2 ⊆ vertexSet ``` Additional definitions: - tail/head stars and negative/positive stars - some special cases (B-Graph, F-Graph, BF-Graph, and what I'm calling a "non-endless" dihypergraph, where neither the source/tail nor the destination/head are empty) - Vertex and (hyper)edge adjacency - isolated vertices - empty and nonempty dihypergraphs The design employed here is based off of #28613, but this PR does not depend on that one. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-combinatorics new-contributor	395/0	Mathlib.lean,Mathlib/Combinatorics/DiHypergraph/Basic.lean	2	2	['github-actions', 'mathlib4-merge-conflict-bot']	b-mehta assignee:b-mehta	19-20768 19 days ago	19-20126 19 days ago	77-696 77 days
36937	Yaohua-Leo author:Yaohua-Leo	feat(Algebra/Jordan): add first linearization lemmas for IsCommJordan	[![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) AI assistance disclosure: I used AI assistance for CI/debugging and module-structure fixes in this PR. The mathematical content and main lemmas were written by me, with help from @pelicanhere. This PR adds a new file `Mathlib/Algebra/Jordan/Linearization.lean` containing linearization lemmas for the commutative Jordan identity. Main declarations: * `IsCommJordan.four_nsmul_associator_mul_add` * `IsCommJordan.associator_mul_add` These lemmas formalize a first linearization of the commutative Jordan identity using `associator`, following McCrimmon, Proposition 1.8.5. --- I put these lemmas in a separate file because I expect follow-up linearization lemmas to belong naturally in the same place. I am also happy to rename declarations or move the file if reviewers would prefer.	t-algebra new-contributor awaiting-author label:t-algebra$	60/0	Mathlib.lean,Mathlib/Algebra/Jordan/Linearization.lean	2	6	['Yaohua-Leo', 'github-actions', 'grunweg', 'ocfnash']	ocfnash assignee:ocfnash	19-14781 19 days ago	19-14781 19 days ago	13-5927 13 days
34182	IlPreteRosso author:IlPreteRosso	refactor(Data/Finsupp): deprecate direct single ↔ Set.indicator shortcuts, add indicator_eq_set_indicator	Routes Finsupp.single ↔ Set.indicator through Pi.single instead of direct shortcuts. Adds `indicator_eq_set_indicator` bridging `Finsupp.indicator` and `Set.indicator` for non-dependent functions. Deprecates `single_eq_set_indicator` and `single_eq_indicator` — users should compose through `single_eq_pi_single` + `Set.indicator_singleton` instead. Golfs `single_eq_update` via `single_eq_pi_single`. Continues #34083.	t-data new-contributor	27/19	Mathlib/Data/Finsupp/Indicator.lean,Mathlib/Data/Finsupp/Single.lean	2	31	['IlPreteRosso', 'eric-wieser', 'github-actions', 'mathlib-bors', 'urkud']	TwoFX assignee:TwoFX	18-72584 18 days ago	18-76472 18 days ago	91-36226 91 days
36813	AlexeyMilovanov author:AlexeyMilovanov	feat(Computability.Encoding): add self-delimiting unary and pair encodings	Adds `unaryPrefix` (a self-delimiting $1^n 0$ code) and `prefixPair` to `Mathlib.Computability.Encoding`. Key changes: * `unaryPrefix`: A prefix-free unary encoding for $\mathbb{N}$, distinct from the existing `unaryEncodeNat`. * `unaryPrefix_append_inj`: A basic cancellation lemma that allows unique extraction of a unary prefix from a concatenated list. * `prefixPair`: A self-delimiting pairing function for boolean lists, defined as $\text{unaryPrefix } \|x\| \frown x \frown y$. * `prefixPair_inj`: A concise proof of pair injectivity leveraging the new prefix lemmas.	t-computability new-contributor awaiting-author	56/1	Mathlib/Computability/Encoding.lean	1	2	['Komyyy', 'github-actions']	Komyyy assignee:Komyyy	18-42202 18 days ago	18-42202 18 days ago	16-41519 16 days
35733	mkaratarakis author:mkaratarakis	feat: Algebraic setup and matrix coefficients for Gelfond-Schneider theorem	This PR introduces the foundational algebraic setup and coefficient bounds required for the proof of the Gelfond-Schneider Theorem (Hilbert's Seventh Problem), which establishes that for algebraic numbers $\alpha \neq 0, 1$ and irrational algebraic $\beta$, the number $\alpha^\beta$ is transcendental. Following the contradiction argument presented in Loo-Keng Hua's "Introduction to Number Theory" (Chapter 17.9, 490 -493) Gelfond's Proof), this file constructs the common number field $K$ and sets up the scaled algebraic integers for the auxiliary linear system. This system will later be solved via Siegel's lemma (Lemma 8.2, 490, Hua). This PR is essentially the first half of page 490 in the book. The proof proceeds by assuming $\gamma = \alpha^\beta$ is algebraic, meaning $\alpha$, $\beta$, and $\gamma$ all lie in an algebraic field $K$ of degree $h$. 1. Bundles the common number field $K$, the complex embeddings, and the algebraic preimages $\alpha', \beta', \gamma'$, alongside the core hypotheses of the theorem. 2. Defines the field degree $h = [K : \mathbb{Q}]$, and bounds $m = 2h + 2$ and $n = q^2 / (2m)$ to control the dimensions of the linear system. 3. Defines $c_1$, a natural number chosen so that $c_1 \alpha$, $c_1 \beta$, and $c_1 \gamma$ are algebraic integers in $K$. We prove numerous bounding and integrality lemmas (`isIntegral_c₁α`, `isInt_β_bound`, etc.). 4. Formalizes the core algebraic coefficients $(a+b\beta)^k \alpha^{al} \gamma^{bl}$ which appear in the evaluation of the derivatives of the auxiliary function $R(x)$. 5. By scaling the system by $c_1^{n-1+2mq}$, we successfully restrict the entries of our linear system matrix `A` entirely to the ring of integers $\mathcal{O}_K$, preparing it for the application of Siegel's lemma. 6. House Bounds (`c₂`) : Establishes the foundational base integer $c_2$ to bound the absolute values of the conjugates (houses) of our coefficients. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-number-theory new-contributor	913/49	Mathlib.lean,Mathlib/NumberTheory/NumberField/House.lean,Mathlib/NumberTheory/Transcendental/GelfondSchneider/MainAlg.lean,Mathlib/RingTheory/IntegralClosure/Algebra/Basic.lean	4	16	['github-actions', 'mkaratarakis', 'tb65536']	tb65536 assignee:tb65536	17-84826 17 days ago	17-83664 17 days ago	30-60258 30 days
37644	matthunz author:matthunz	feat(Order/Causal): add `Causal` ordering for stream functions	Adds `Causal` ordering for stream functions and related theorems: ```lean def Causal (f : Stream' α → Stream' β) : Prop := ∀ (x y : Stream' α) (t : ℕ), (∀ s, s ≤ t → x s = y s) → f x t = f y t ``` A stream function is causal if the output at time `t` depends only on inputs up to time `t`. Causal stream functions are commonly used in signal processing, reactive systems, and semantics of stateful computations, where outputs cannot depend on future inputs. ## Future work - Mealy machines: define Mealy machines as causal stream functions with state, and relate them to standard automata-theoretic constructions. - Feedback and delay operators: formalize feedback loops and delayed composition, enabling modeling of stateful and recursive stream definitions. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-order	79/0	Mathlib.lean,Mathlib/Order/Causal/Basic.lean,Mathlib/Order/Causal/Defs.lean	3	2	['github-actions']	nobody	17-67665 17 days ago	unknown	unknown
37666	TJHeeringa author:TJHeeringa	feat(Analysis/InnerProductSpace/Reproducing): Lipschitz wrt the kernel pseudometric	--- RKHSs $H$ have bounded point evaluations. This induces a pseudometric on the underlying space `X`. The function $f\in H$ are Lipschitz continuous with Lipschitz constant $\\|\|f\\|\|$. This PR puts the pseudometric instance inline. The instance cannot just be put outside the theorem, because that gives problems with resolving type classes / instance synthesis. An alternative to inlining the instance is a type class synonym. One copy would be the RKHS with whatever metric X came equipped with and one copy would be the RKHS with the induced metric. Since there are likely more theorems depending on this pseudometric, I suspect that it is actually a better solution. AI: I had the instance outside the theorem. Lean gave problems with resolving type classes / instance synthesis. I asked Claude and ChatGPT to interpret the error and fix it. The latter just spit gibberish and the former suggested inlining but in a way that didn't work. Then, I asked on Zulip and got the same suggestion but working. The type synonym alternative was also suggested there. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-analysis new-contributor help-wanted	20/3	Mathlib/Analysis/InnerProductSpace/Reproducing.lean	1	3	['TJHeeringa', 'github-actions']	nobody	15-84422 15 days ago	unknown	unknown
37707	MavenRain author:MavenRain	feat(Combinatorics/SimpleGraph): add IsMaximalClique/IsMaximalIndepSet, refactor IsMaximum* to MaximalFor	Addresses #34962	new-contributor t-combinatorics	92/31	Mathlib/Combinatorics/SimpleGraph/Clique.lean,MathlibTest/ClearUnneeded.lean	2	2	['github-actions']	nobody	15-71061 15 days ago	unknown	unknown
37695	Morten-Ness author:Morten-Ness	refactor(GroupTheory/Complement): simplify complement proofs	Simplifies the proofs of: - `Subgroup.IsComplement'.symm` - `Subgroup.isComplement_singleton_left` - `Subgroup.isComplement_singleton_right` No API changes. AI assistance: I used Codex/LLM suggestions as a starting point, then manually checked the proofs, and verified the final version locally. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-group-theory new-contributor awaiting-author	15/17	Mathlib/GroupTheory/Complement.lean	1	4	['github-actions', 'tb65536']	tb65536 assignee:tb65536	15-22955 15 days ago	15-22955 15 days ago	0-66893 18 hours
37489	michael-novak-math author:michael-novak-math	feat: add the fundamental theorem of plane curves	We add to the PlaneCurves file created in PR #36731 a classical result in the subject of differential geometry of plane curves: the fundamental theorem of plane curves. --------- - [ ] depends on: #36731	new-contributor t-differential-geometry t-analysis blocked-by-other-PR	651/0	Mathlib.lean,Mathlib/Analysis/InnerProductSpace/Calculus.lean,Mathlib/Geometry/PlaneCurves.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral/FundThmCalculus.lean,docs/references.bib	5	5	['github-actions', 'mathlib-dependent-issues', 'michael-novak-math']	nobody	15-13535 15 days ago	20-84791 20 days ago	0-11137 3 hours
37716	slavanaprienko author:slavanaprienko	feat(LinearAlgebra/Matrix/Determinant): Desnanot-Jacobi identity	This PR adds the Desnanot-Jacobi identity (also known as the Lewis Carroll identity or Dodgson condensation): for any (n+2)×(n+2) matrix M over a commutative ring, $$\det(M) \cdot \det(M_{1,n}^{1,n}) = \det(M_1^1) \cdot \det(M_n^n) - \det(M_1^n) \cdot \det(M_n^1)$$ The proof follows Bressoud's Proofs and Confirmations (Cambridge University Press, 1999): multiply M by an auxiliary matrix built from columns of the adjugate, then compare determinants. This yields the identity premultiplied by det(M). To cancel, we pass to a universal polynomial ring (an integral domain with nonzero determinant), then specialize back to arbitrary commutative rings. It seems there's some interest in adding this: https://leanprover.zulipchat.com/#narrow/channel/217875-Is-there-code-for-X.3F/topic/Determinantal.20identity.20and.20the.20Cauchy.20matrix.20determinant/with/582946873 ---	t-algebra new-contributor awaiting-author label:t-algebra$	252/0	Mathlib.lean,Mathlib/LinearAlgebra/Matrix/Determinant/DesnanotJacobi.lean	2	7	['github-actions', 'grunweg', 'slavanaprienko']	nobody	14-79939 14 days ago	15-26584 15 days ago	0-30561 8 hours
36313	SproutSeeds author:SproutSeeds	feat(Inversion): cobounded tendsto near center	Part of #5939 Add `tendsto_inversion_nhdsNE_center_cobounded` in `Mathlib/Geometry/Euclidean/Inversion/Basic.lean`, proving `Tendsto (inversion c R) (𝓝[≠] c) (Bornology.cobounded P)` for `R ≠ 0`. Tools used: Codex 5.3 extra high --- Happy to adjust naming, placement, or proof style based on maintainer preference.	t-euclidean-geometry new-contributor LLM-generated awaiting-author	42/0	Mathlib/Geometry/Euclidean/Inversion/Basic.lean	1	9	['SproutSeeds', 'github-actions', 'jsm28', 'kbuzzard', 'ocfnash']	jsm28 assignee:jsm28	14-67341 14 days ago	29-15360 29 days ago	6-36700 6 days
35755	Vilin97 author:Vilin97	feat(Analysis/ODE): forward Euler method convergence	WIP Prove the convergence of the Forward Euler Method. This is the first theorem in most textbooks on numerical analysis for ODEs. --- The initial proof was produced by [Aristotle](https://aristotle.harmonic.fun). The code was then iteratively refined (factoring out lemmas, golfing, simplifying proofs) using Claude Code (Claude Opus 4.6). * [ ] Depends on #35753	new-contributor WIP LLM-generated merge-conflict	297/0	Mathlib.lean,Mathlib/Analysis/ODE/EulerMethod.lean,Mathlib/Topology/Algebra/Order/Floor.lean,Mathlib/Topology/Algebra/Order/PiecewiseLinear.lean	4	4	['github-actions', 'mathlib-merge-conflicts']	nobody	14-54991 14 days ago	unknown	unknown
36698	ghseeli author:ghseeli	feat(Combinatorics/Enumerative): Latin squares	This PR defines Latin rectangles and Latin squares and proves an extension theorem using Hall's Marriage Theorem. ## Main results - `group_to_cayley_table`: every finite group `G` yields a `LatinSquare G G`. - `latin_rectangle_extends_one_row`: a (non-square) `LatinRectangle` extends to a `LatinRectangle` with one more row. This is an application of Hall's Marriage Theorem, `hallMatchingsOn.nonempty`. - `latin_rectangle_extends_to_latin_square`: a `LatinRectangle` extends to a `LatinSquare`. This is included in a new file `Combinatorics/Enumerative/LatinSquare.lean`. --- - [ ] depends on: #37190 - [ ] depends on: #37720 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-combinatorics blocked-by-other-PR	642/0	Mathlib.lean,Mathlib/Combinatorics/Enumerative/DoubleCounting.lean,Mathlib/Combinatorics/Enumerative/LatinSquare.lean,Mathlib/Combinatorics/Pigeonhole.lean,Mathlib/Data/Fintype/Card.lean,docs/references.bib	6	78	['SnirBroshi', 'cjrl', 'eric-wieser', 'ghseeli', 'github-actions', 'mathlib-dependent-issues', 'vlad902']	nobody	14-51522 14 days ago	18-75249 18 days ago	16-20262 16 days
36849	mike1729 author:mike1729	feat(Analysis/Normed/Module/SchauderBasis): basic sequences and Grünblum criterium	This PR introduces the theory of basic sequences in Banach spaces, following Albiac–Kalton. Defines basic sequences in normed spaces, and prove the classical Grünblum criterium for recognizing them. ### Main Definitions - `IsBasicSequence`: A `Prop` asserting that initial partial sums of `e` are bounded by `K` times the full partial sum. - `IsBasicSequence.toSchauderBasis`: Constructs a `SchauderBasis` on the algebraic span of a nonzero basic sequence. ### Main Results - `IsBasicSequence.linearIndependent`: A nonzero basic sequence is linearly independent. - `IsBasicSequence.coe_toSchauderBasis_apply`: The `n`-th basis vector of the constructed Schauder basis coerces to `e n` in the ambient space. - `IsBasicSequence.enormProjBound_le`: The projection bound of the constructed basis is at most `ENNReal.ofReal K`. --- - follow up to : #34209 - blocks : #35473 The next planned PRs: - general selection principle for basic sequences - characterization when a set contains a basic sequence in terms of weak closure and compactness - Eberlein–Šmulian theorem - weakly compact subsets of a Banach space are Fréchet–Urysohn spaces [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	file-removed t-analysis new-contributor	278/1	Mathlib.lean,Mathlib/Analysis/Normed/Module/SchauderBasis/Basic.lean,Mathlib/Analysis/Normed/Module/SchauderBasis/BasicSequence.lean	3	7	['github-actions', 'j-loreaux', 'mike1729']	sgouezel assignee:sgouezel	14-18322 14 days ago	14-20351 14 days ago	33-41545 33 days
37281	AltSoKoly author:AltSoKoly	Update EdgeConnectivity.lean	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-combinatorics new-contributor awaiting-author	123/0	Mathlib/Combinatorics/SimpleGraph/Connectivity/EdgeConnectivity.lean,Mathlib/Data/Int/GCD.lean	2	5	['github-actions', 'grunweg', 'themathqueen']	nobody	14-2146 14 days ago	unknown	unknown
26165	oliver-butterley author:oliver-butterley	feat(MeasureTheory.VectorMeasure): add lemma which shows that variation of a `ℝ≥0∞` VectorMeasure is equal to itself	Add a lemma for the variation of a VectorMeasure which tells that if `μ` is `VectorMeasure X ℝ≥0∞` then `variation μ = μ`. Co-authored-by: @yoh-tanimoto - [ ] depends on: #26160 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict new-contributor t-measure-probability awaiting-author	467/0	Mathlib.lean,Mathlib/MeasureTheory/VectorMeasure/Variation/Defs.lean,Mathlib/MeasureTheory/VectorMeasure/Variation/Lemmas.lean	3	3	['github-actions', 'mathlib-dependent-issues', 'mathlib4-merge-conflict-bot']	nobody	13-32955 13 days ago	291-21844 291 days ago	15-65730 15 days
37456	Robertboy18 author:Robertboy18	feat(LinearAlgebra/AffineSpace): add Desargues's theorem	This PR adds an affine (parallel) version of Desargues's theorem! Main changes - New file `Mathlib/LinearAlgebra/AffineSpace/Desargues.lean` with `parallel_third_side_of_perspective`: if two triangles are in perspective from a point `S` and two pairs of corresponding sides are parallel, then the third pair of sides is parallel. - Add the corresponding `public import` to `Mathlib.lean`. - Update `docs/100.yaml` (entry #87) to point to the new declaration. High level Proof idea is from the rocq repository! Compare side vectors via `exists_eq_smul_of_parallel` for the two given pairs of parallel sides; the shared comparison along `SA` forces the same scalar, yielding parallelism of the third sides. Tests: `lake build Mathlib.LinearAlgebra.AffineSpace.Desargues`!	t-algebra new-contributor awaiting-author label:t-algebra$	159/0	Mathlib.lean,Mathlib/LinearAlgebra/AffineSpace/Desargues.lean,docs/100.yaml	3	8	['Robertboy18', 'SnirBroshi', 'copilot-pull-request-reviewer', 'github-actions', 'wwylele']	eric-wieser assignee:eric-wieser	13-2739 13 days ago	13-2739 13 days ago	8-70344 8 days
37682	SabrinaJewson author:SabrinaJewson	refactor(Order/OrdContinuous): redefine left and right order continuity to not require preserving ⊥/⊤	`LeftOrdContinuous` currently requires that `f ⊥ = ⊥`, but this means that many functions that are perhaps intuitively left-continuous (like `f x = x + 1` on `ℝ≥0`) are not. In particular, this change means that functions between conditionally complete lattices are `LeftOrdContinuous` iff they are monotone and topologically left continuous (see `MonotoneOn.map_csSup_of_continuousWithinAt` for the reverse direction). If one wants the concept that existed before, one can either accept the `f ⊥ = ⊥` hypothesis separately or, if the function is between complete lattices, use the left side of a `GaloisConnection` (which is equivalent, although I think this is not yet in Mathlib). This removes the definitional equality of the type in favour of a structure. Since most of the time users will be working with the `sSup` versions and not with `IsLUB`, I think this is justified. As a consequence, this removes the definitional equality between `LeftOrdContinuous` and `RightOrdContinuous` of the dual – the latter could be redefined to re-add this, but we do have conversion functions. `LeftOrdContinuous.continuousWithinAt_Iic` is rewritten to accomodate these changes; the superfluous `DenselyOrdered` assumption is also removed. [Zulip thread](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/LeftOrdContinuous.20requires.20f.28.E2.8A.A5.29.20.3D.20.E2.8A.A5/near/582932491) --- - [x] depends on: #37735 - [x] depends on: #37772 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-order	52/38	Mathlib/Order/OrdContinuous.lean,Mathlib/Order/SemiconjSup.lean,Mathlib/Topology/Order/Basic.lean	3	10	['SabrinaJewson', 'astrainfinita', 'github-actions', 'mathlib-dependent-issues', 'mathlib-merge-conflicts', 'vihdzp']	nobody	12-59383 12 days ago	12-57796 12 days ago	14-51849 14 days
35812	khwilson author:khwilson	feat(MeasureTheory/Group/GeometryOfNumbers): successive minima and existence of a directional basis	Define the successive minima of a discrete subgroup of a real vector space with respect to a convex set. These invariants show up throughout the geometry of numbers and are the focus of Minkowski's Second Theorem (whose statement is left here with a `proof_wanted`). Note: The key lemma is that the "gauge set" of the convex set is closed. I took the approach of showing that it is sequentially closed. There's an alternative approach via showing it's the union of a finite number of closed sets. I personally thought this approach was more intuitive, but the union approach may result in a slightly shorter proof. Co-authored-by: Yaël Dillies --- - [ ] depends on #37738 - [x] depends on #37740 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-measure-probability awaiting-author merge-conflict	544/77	Mathlib/Algebra/Module/ZLattice/Basic.lean,Mathlib/Analysis/Convex/Basic.lean,Mathlib/Analysis/Convex/Body.lean,Mathlib/Analysis/Convex/Gauge.lean,Mathlib/Analysis/Polynomial/Basic.lean,Mathlib/Analysis/SpecialFunctions/Complex/LogBounds.lean,Mathlib/LinearAlgebra/Basis/Fin.lean,Mathlib/LinearAlgebra/Basis/Submodule.lean,Mathlib/LinearAlgebra/FiniteDimensional/Lemmas.lean,Mathlib/LinearAlgebra/LinearIndependent/Basic.lean,Mathlib/LinearAlgebra/LinearIndependent/Lemmas.lean,Mathlib/MeasureTheory/Group/GeometryOfNumbers.lean,Mathlib/RingTheory/Polynomial/Bernstein.lean,Mathlib/Topology/Instances/Int.lean,Mathlib/Topology/Instances/Real/Lemmas.lean,Mathlib/Topology/Order/Bornology.lean	16	32	['Vierkantor', 'YaelDillies', 'github-actions', 'joneugster', 'khwilson', 'mathlib-merge-conflicts']	YaelDillies assignee:YaelDillies	12-38180 12 days ago	18-26383 18 days ago	36-13256 36 days
28546	Sfgangloff author:Sfgangloff	feat(SymbolicDynamics): basic setup of Zd, full shift, cylinders, pat…	This PR adds a group-generic foundation for symbolic dynamics over an arbitrary group `G`, together with convenient specializations for `ℤ` and `ℤ^d`. Summary of additions: - Full shift and shift action - `abbrev FullShift (A G) := G → A` (inherits product topology from the Π-type). - Right shift `shift g x` with convention `(shift g x) h = x (h * g)`. - Cylinders and topology - `cylinder U x : Set (G → A)` for finite `U : Finset G`. - Cylinders are open under `[DiscreteTopology A]`; with a finite alphabet they are also closed. - Equality with dependent products: `cylinder U x = Set.pi (↑U) (fun i => ({x i} : Set A))`, enabling use of the `Set.pi` API. - Patterns, occurrences, and subshifts - `Pattern A G` with finite `support : Finset G` and `data : support → A`. - `Pattern.occursIn p x g` (occurrence at translate `g`) and the expected shift law. - `forbids F` and `Subshift A G` (closed, shift-invariant subsets). - `FixedSupport A G U` with an equivalence to `(U → A)` to obtain finiteness. - Language on finite shapes and counting - `languageOn X U`, `languageCardOn X U`, and `patternCountOn Y U`. - Entropy along a shape sequence - `limsupAtTop` (as an `sInf` of eventual upper bounds). - `entropyAlong X F hF := limsup (log (patternCountOn X (F n) + 1) / \|F n\|)` for any nonempty finite shapes `F : ℕ → Finset G` (the `+ 1` avoids `log 0`). - Specializations - `IntShapes`: segments `[-n,n]` on `Multiplicative ℤ`, with `entropy_Z`. - `ZdShapes`: boxes `[-n,n]^d` on `ℤ^d` (as functions `Fin d → ℤ`), with `entropy_Zd`. Mathematical remarks: - The API is shape-parametric: entropy is defined along user-provided finite shapes. - On amenable groups, using a Følner sequence yields a canonical value (Ornstein–Weiss). This PR does not assume amenability; the family of shapes is an explicit input. Motivation: Provide a clean, reusable base for symbolic dynamics on groups in mathlib. Future work: - Add a Følner predicate and prove shape-independence / limit existence on amenable groups. - Expand the `ℤ`/`ℤ^d` toolkit (alternative shapes, mixing, factors). - Develop 1D theory and, longer-term, multidimensional SFT results (e.g. along the lines of Hochman–Meyerovitch).	t-dynamics new-contributor	665/0	Mathlib.lean,Mathlib/Dynamics/SymbolicDynamics/Basic.lean,Mathlib/Tactic/Translate/ToAdditive.lean	3	183	['Sfgangloff', 'botbaki-review', 'eric-wieser', 'github-actions', 'kckennylau', 'mathlib4-merge-conflict-bot', 'sgouezel']	urkud assignee:urkud	12-36190 12 days ago	12-34848 12 days ago	148-32044 148 days
33443	sahanwijetunga author:sahanwijetunga	feat: Define Isometries of Bilinear Spaces	--- We define Isometries of Bilinear Spaces, closely following the implementation of isometries of quadratic spaces. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra new-contributor maintainer-merge label:t-algebra$	278/0	Mathlib.lean,Mathlib/LinearAlgebra/BilinearForm/Isometry.lean,Mathlib/LinearAlgebra/BilinearForm/IsometryEquiv.lean	3	25	['github-actions', 'robin-carlier', 'sahanwijetunga']	mattrobball assignee:mattrobball	12-27116 12 days ago	12-27275 12 days ago	60-48741 60 days
37879	mrdouglasny author:mrdouglasny	feat(Analysis): absolutely monotone functions, Bernstein theorem, and Schur exponential	This is a draft PR for early feedback. It introduces the theory of absolutely monotone functions and proves the generalized Schur exponential theorem. ## What it contains `Mathlib/Analysis/Calculus/AbsolutelyMonotone.lean` (new, ~980 lines) Defines `AbsolutelyMonotoneOn f s` for smooth functions with nonneg iterated derivatives: ```lean structure AbsolutelyMonotoneOn (f : ℝ → ℝ) (s : Set ℝ) : Prop where contDiffOn : ContDiffOn ℝ ∞ f s nonneg : ∀ n : ℕ, ∀ x ∈ s, 0 ≤ iteratedDerivWithin n f s x ``` Main results: - Closure under `add`, `smul`, `mul` - Examples: `exp`, `cosh`, `pow`, nonneg constants - Bernstein backward: nonneg power series ⇒ absolutely monotone - Bernstein forward (`analyticWithinAt_zero_of_nonneg_iteratedDerivWithin`): smooth + nonneg iterated derivatives on a convex set containing 0 ⇒ analytic at 0 within the set The forward direction uses Taylor theorem with integral remainder plus a Widder-style estimate. `Mathlib/Analysis/Matrix/Order.lean` (additions, ~83 lines) Following the recently-merged Schur product theorem (#37297): - `Matrix.hadamardPow` — n-th entrywise power - `Matrix.PosSemidef.hadamardPow` — Hadamard powers preserve PSD - `Matrix.PosSemidef.map_of_nonneg_coeffs` — entrywise nonneg power series preserves PSD - `Matrix.PosSemidef.map_exp` — entrywise exp preserves PSD ## Questions for reviewers 1. Definition: Is `ContDiffOn ℝ ∞` (smooth, not analytic) the right condition? 2. File placement: `Mathlib/Analysis/Calculus/AbsolutelyMonotone.lean` — or `Analytic/`? 3. Scope: ~1066 lines total. Should this be split into multiple PRs? 4. Naming: `analyticWithinAt_zero_of_nonneg_iteratedDerivWithin` is descriptive but long. Suggestions? 5. Bernstein theorem for absolutely monotone functions is not currently in mathlib (the existing `Bernstein.lean` is about Bernstein polynomial approximation, a different theorem). ## Notes - Zero sorries, standard axioms only - Builds cleanly against current master - Companion to the Schur product theorem #37297	t-analysis new-contributor	1072/0	Mathlib.lean,Mathlib/Analysis/Calculus/AbsolutelyMonotone.lean,Mathlib/Analysis/Matrix/Order.lean	3	4	['github-actions', 'mrdouglasny']	nobody	12-4965 12 days ago	unknown	unknown
36785	hommmmm author:hommmmm	feat(RingTheory/Localization): Nagata's criterion for primality in localization away	## Summary - Add `dvd_of_mem_span_singleton_localization`: if `p` is prime and `p ∤ x`, then membership in the span of the image of `x` in `R[1/p]` implies divisibility by `x`. - Add `prime_of_prime_in_localization` (Nagata's criterion): if `p` is prime, `x` is irreducible, and the image of `x` in `R[1/p]` is prime, then `x` is prime. ## References - [Stacks Project, Tag 0AFU](https://stacks.math.columbia.edu/tag/0afu) ## AI Disclosure This code is written without AI, then uses Claude Code with cameronfreer's [Lean4-skills](https://github.com/cameronfreer/lean4-skills) (specifically, the `review`, `refactor`, and `golf` workflow) for style changes, refactoring and golfing. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-ring-theory new-contributor awaiting-author	50/0	Mathlib/RingTheory/Localization/Away/Basic.lean	1	6	['chrisflav', 'github-actions', 'hommmmm']	chrisflav assignee:chrisflav	11-74182 11 days ago	12-25277 12 days ago	22-69086 22 days
37111	tannerduve author:tannerduve	feat(Computability): add Nat.PrimrecIn and PrimrecIn	- Add `Nat.PrimrecIn`: primitive recursive functions relative to a set of oracles - Add `PrimrecIn`: lifts `Nat.PrimrecIn` to `Primcodable` types A `PrimrecIn` version of `RecursiveIn.iff_nat` (i.e., `PrimrecIn O (f : ℕ → ℕ) ↔ Nat.PrimrecIn O f`) is left as future work as it requires proving `Nat.PrimrecIn O Nat.pred`, which needs additional API for `Nat.PrimrecIn`. --- Split out from #34937 as requested in review. - [x] depends on: #37061	t-computability new-contributor awaiting-author	24/0	Mathlib/Computability/RecursiveIn.lean	1	14	['Komyyy', 'bryangingechen', 'github-actions', 'mathlib-dependent-issues', 'mathlib-merge-conflicts', 'tannerduve']	nobody	11-67059 11 days ago	12-79918 12 days ago	1-77226 1 day
36763	alok author:alok	refactor(Order/Filter/Germ): partial sections for Filter.Product	## Summary - Refactor `Filter.Product` from total functions to partial sections (`Product.Section`) with filter-large domains - Adapt the model-theoretic `Prestructure` and Łoś's theorem proofs to partial sections - Add `Germ ↔ Product` bridge equivalence for constant families ## Motivation The current `Filter.Product` is a quotient of total functions `(a : α) → ε a` by eventual equality. This requires all fibers to be inhabited, which is not the mathematically correct construction. The ultraproduct should only require a section defined on a filter-large set. The new `Product.Section` structure carries: - A domain `dom : Set α` with `dom ∈ l` - A dependent section `val : (a : dom) → ε a` Two sections are equivalent if they agree on some filter-large common domain. This matches the standard mathematical construction and enables proper ultraproducts where some fibers may be empty. ## Changes ### `Mathlib/Order/Filter/Germ/Basic.lean` - New `Product.Section` structure (partial section with filter-large domain) - `productSetoid` redefined over `Product.Section` - `Product.ofTotal` embeds total sections; `eq_iff_ofTotal` characterizes equality ### `Mathlib/ModelTheory/Ultraproducts.lean` - `sectionStructure`: first-order structure on partial sections (funMap restricts to domain intersection, RelMap checks on common domain) - `setoidPrestructure` adapted with full proofs of `fun_equiv` and `rel_equiv` - `funMap_cast`, `boundedFormula_realize_cast` (rel case), `all` quantifier case all reproved for partial sections - Łoś's theorem statement unchanged; `sentence_realize` still has the same API ### `Mathlib/Order/Filter/Germ/Product.lean` (new) - `Germ.toProduct` / `Product.toGerm`: round-trip between germs and constant-family products - `Germ.prodEquiv`: equivalence for inhabited constant families (backward compat) ## Test plan - [x] `lake build` passes (7607/7607 modules) - [x] All linter warnings resolved - [x] `Mathlib.ModelTheory.Satisfiability` (uses `Filter.Product` + `sentence_realize`) still compiles - [x] `Mathlib.Analysis.Real.Hyperreal` still compiles --- Context: [Zulip discussion](https://leanprover.zulipchat.com/#narrow/channel/217875-Is-there-code-for-X.3F/topic/Nonstandard.20Analysis/near/513178715) — Violeta Hernández asked for fixing the ultraproduct definition as the first step after #33650 deprecated the old hyperreal machinery. 🤖 Generated with [Claude Code](https://claude.com/claude-code)	new-contributor merge-conflict	278/49	Mathlib.lean,Mathlib/ModelTheory/Ultraproducts.lean,Mathlib/Order/Filter/Germ/Basic.lean,Mathlib/Order/Filter/Germ/Product.lean	4	5	['alok', 'github-actions', 'mathlib-merge-conflicts', 'plp127']	nobody	11-61103 11 days ago	unknown	unknown
35394	HugLycan author:HugLycan	feat(Tactic/Positivity): make positivity work for types that are not partial orders	Make positivity work for types that are not partial orders Most PositivityExt haven't been updated for non partial order cases yet. They will be updated in the later PR. `Strictness` now does not depend `Q(PartialOrder $α)`, and the constructors of `Strictness` now have their order typeclass arguments. In order to help `Qq` synth instances property, we have to move `assertInstancesCommute` to inner branch, manually add `haveI'` or explicitly pass the order typeclass instance into `.positive`/`.nonnegative`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-meta	611/322	Mathlib/Algebra/Order/AbsoluteValue/Basic.lean,Mathlib/Algebra/Order/Algebra.lean,Mathlib/Algebra/Order/BigOperators/Expect.lean,Mathlib/Algebra/Order/BigOperators/Ring/Finset.lean,Mathlib/Algebra/Order/Field/Basic.lean,Mathlib/Algebra/Order/Field/Power.lean,Mathlib/Algebra/Order/Floor/Extended.lean,Mathlib/Algebra/Order/Floor/Ring.lean,Mathlib/Algebra/Order/Module/Field.lean,Mathlib/Analysis/Complex/BorelCaratheodory.lean,Mathlib/Analysis/Complex/Order.lean,Mathlib/Analysis/SpecialFunctions/Bernstein.lean,Mathlib/Analysis/SpecialFunctions/Gamma/Basic.lean,Mathlib/Analysis/SpecialFunctions/Pow/NNReal.lean,Mathlib/Analysis/SpecialFunctions/Pow/Real.lean,Mathlib/Analysis/SpecialFunctions/Trigonometric/Arctan.lean,Mathlib/Analysis/SpecialFunctions/Trigonometric/DerivHyp.lean,Mathlib/Combinatorics/Enumerative/DyckWord.lean,Mathlib/Combinatorics/SimpleGraph/Triangle/Removal.lean,Mathlib/Data/ENNReal/Basic.lean,Mathlib/Data/ENNReal/Real.lean,Mathlib/Data/EReal/Basic.lean,Mathlib/Data/EReal/Inv.lean,Mathlib/Data/EReal/Operations.lean,Mathlib/Data/NNReal/Defs.lean,Mathlib/Data/Nat/Totient.lean,Mathlib/Data/Rat/Cast/Order.lean,Mathlib/Data/Real/Sqrt.lean,Mathlib/MeasureTheory/Integral/Bochner/Basic.lean,Mathlib/MeasureTheory/Measure/Real.lean,Mathlib/NumberTheory/ArithmeticFunction/Misc.lean,Mathlib/NumberTheory/ArithmeticFunction/Zeta.lean,Mathlib/NumberTheory/LucasLehmer.lean,Mathlib/Tactic/Positivity/Basic.lean,Mathlib/Tactic/Positivity/Core.lean,Mathlib/Tactic/Positivity/Finset.lean,Mathlib/Topology/Algebra/InfiniteSum/Order.lean	37	23	['HugLycan', 'JovanGerb', 'fpvandoorn', 'github-actions', 'joneugster']	dwrensha assignee:dwrensha	11-51334 11 days ago	34-21798 34 days ago	34-21211 34 days
37871	JJYYY-JJY author:JJYYY-JJY	feat: support intros and simple rintro in introMerge	* Extend the `introMerge` linter to handle `intros` and a safe subset of `rintro` tactics, allowing it to suggest merging a wider variety of adjacent introduction tactics. * Introduce helper functions to normalize supported `rcases` and `rintro` patterns into equivalent `intro` arguments for consistent analysis. * Add tests to verify the correct merging of mixed introduction tactics and ensure intervening tactics prevent merging. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-meta new-contributor	101/9	Mathlib/Dynamics/OmegaLimit.lean,Mathlib/Tactic/TacticAnalysis/Declarations.lean,MathlibTest/TacticAnalysis.lean	3	3	['copilot-pull-request-reviewer', 'github-actions']	dwrensha assignee:dwrensha	11-51322 11 days ago	12-38822 12 days ago	12-38235 12 days
37774	weisbrja author:weisbrja	fix: change variables in `bicompl` to `Sort*` and add missing theorem mentioned in `bicompl` docs	[#mathlib4 > Why does Mathlib use Type* instead of Sort* in some places?](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Why.20does.20Mathlib.20use.20Type.2A.20instead.20of.20Sort.2A.20in.20some.20places.3F/with/583882342) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-logic	6/1	Mathlib/Logic/Function/Basic.lean	1	7	['github-actions', 'kbuzzard', 'leanprover-radar', 'weisbrja']	nobody	10-68843 10 days ago	10-74612 10 days ago	14-52955 14 days
37928	AlexeyMilovanov author:AlexeyMilovanov	refactor(Computability.Encoding): unbundle Γ and remove FinEncoding	This PR unbundles the alphabet `Γ` from the `Encoding` structure and completely removes `FinEncoding`. `Encoding`: The alphabet `Γ` is now an explicit parameter: `structure Encoding (α : Type u) (Γ : Type v)`. `FinEncoding`: Removed. Finiteness is now handled via standard typeclasses (e.g., `[Fintype Γ] (e : Encoding α Γ)`). Combinators: Functions like `finEncodingPair` are simplified to `encodingPair`, dropping the `fin` prefix and `[Fintype]` requirements where no longer needed. Downstream: Mechanically updated `Mathlib.Computability` and `Mathlib.ModelTheory` to pass the explicit `Γ` and use `[Fintype Γ]` where `FinEncoding` was previously required.	new-contributor	30/67	Mathlib/Computability/Encoding.lean,Mathlib/ModelTheory/Encoding.lean	2	5	['github-actions', 'vihdzp']	nobody	10-58527 10 days ago	10-57860 10 days ago	11-15422 11 days
33985	YellPika author:YellPika	feat(Order/OmegaCompletePartialOrder): `OmegaCompletePartialOrder` instance for `Sum` with basic `ωScottContinuous` lemmas	This PR adds an `OmegaCompletePartialOrder` instance for `Sum`, along with `ωScottContinuous` lemmas for basic operations (`inl`, `inr`, `elim`). Appropriate lemmas are marked with `@[fun_prop]` so that the `fun_prop` tactic can automatically deduce `ωScottContinuous` proofs for functions involving `Sum`s (e.g. see the proof of `Sum.ωScottContinuous_map`). --- - [x] depends on: #33941 - [x] depends on: #37258 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor large-import t-order awaiting-author	205/3	Mathlib/Data/Sum/Basic.lean,Mathlib/Data/Sum/Order.lean,Mathlib/Order/OmegaCompletePartialOrder.lean,Mathlib/Order/ScottContinuity.lean,Mathlib/Topology/Constructions/SumProd.lean	5	56	['Vierkantor', 'YaelDillies', 'YellPika', 'github-actions', 'mathlib-dependent-issues', 'mathlib-merge-conflicts', 'vihdzp']	YaelDillies and pechersky assignee:pechersky assignee:YaelDillies	10-54162 10 days ago	23-23096 23 days ago	52-33797 52 days
37954	jdhart81 author:jdhart81	feat(Data/ENNReal/Inv): add ENNReal.div_mul_div_cancel	Proves a / b * (b / c) = a / c for b ≠ 0, b ≠ ∞ in ENNReal. Proof via mul_div_assoc and existing div_mul_cancel. AI Disclosure: This PR was developed with assistance from an LLM (Claude, Anthropic) for proof exploration and text drafting. The proof was compiled and verified locally by the contributor, who understands the mathematical content. This lemma is extracted from a larger formalization of information-theoretic bounds (Zenodo DOI: 10.5281/zenodo.19317983). --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data new-contributor	5/0	Mathlib/Data/ENNReal/Inv.lean	1	2	['github-actions']	nobody	10-3518 10 days ago	unknown	unknown
37720	cjrl author:cjrl	feat(Data/Fintype/Card): existsUnique_notMem_image_of_injective_of_card_succ	This pull requests adds a small theorem `existsUnique_notMem_image_of_injective_of_card_succ` to `Mathlib/Data/Fintype/Card` that says given an injective map f : α → β such that β has cardinality one more than α, there exists a unique element of β not in the image of f. This can be viewed as going in the opposite direction of `card_lt_of_injective_of_notMem`. This little fact is needed for our Latin Square PR #36698. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data new-contributor t-set-theory	15/0	Mathlib/Data/Fintype/Card.lean	1	6	['IvanRenison', 'cjrl', 'github-actions']	nobody	9-71831 9 days ago	9-68971 9 days ago	15-30610 15 days
37190	cjrl author:cjrl	feat(Combinatorics): Set-Valued Pigeonhole Principle	This PR contributes two theorems to combinatorics: - `exists_lt_card_cover_of_card_biUnion_lt_card` is a set-valued version of the pigeonhole principle. - `sum_card_eq_sum_card_cover_biUnion` is a set theoretic corollary of a double counting result proved for bipartite graphs (`Finset.sum_card_bipartiteAbove_eq_sum_card_bipartiteBelow`). This was needed to prove the above pigeonhole principle. The motivation for these results is our Latin Square PR #36698. These results were proved in less general terms in that PR, but are independent of Latin Square considerations and so we have generalized and moved them into more relevant files. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-combinatorics	38/0	Mathlib/Combinatorics/Enumerative/DoubleCounting.lean,Mathlib/Combinatorics/Pigeonhole.lean	2	16	['IvanRenison', 'cjrl', 'ghseeli', 'github-actions', 'j-loreaux', 'vlad902']	nobody	9-71023 9 days ago	9-70328 9 days ago	25-35001 25 days
34007	martinwintermath author:martinwintermath	feat(Algebra/Module/Submodule/Dual): dual operator for submodules	Add new file `Dual.lean` that defines the dual operator for submodules. The main definition is * `Submodule.dual`: given a bilinear pairing `p` between two modules `M₁` and `M₂` and a submodule `S` in `M₁`, `Submodule.dual p S` is the submodule in `M₂` consisting of all points `y` such that `0 = p x y` for all `x ∈ S`. For reasons of generality, `p` is actually a general sesqui-bilinear map, that is, of the form `p : M₁ →ₛₗ[I₁] M₂ →ₛₗ[I₂] M`. This implementation of the `dual` operator for submodules is written to parallel the implementation of `PointedCone.dual`. Include some additional results: * theorems that represent the dual as the kernel of a linear map * theorems for the relation between dual and the `dualAnnihilator` and `dualCoannihilator` of a submodule. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra new-contributor awaiting-author label:t-algebra$	239/0	Mathlib.lean,Mathlib/Algebra/Module/Submodule/Dual.lean	2	7	['github-actions', 'joelriou', 'martinwintermath', 'mathlib-bors']	joelriou assignee:joelriou	9-66687 9 days ago	81-70972 81 days ago	14-78173 14 days
35834	homeowmorphism author:homeowmorphism	feat(Mathlib/GroupTheory/PresentedGroup): every group has a presentation	We show that every group has a presentation defined by taking the free group with all of the group elements as the generators, and defining the relations as the kernel of the induced subjective homomorphism from that free group to the group itself. Use of AI: This has been vibe-coded with GPT-Codex-5.3, was updated through review, and was double-checked by the author. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-group-theory large-import awaiting-author LLM-generated	29/1	Mathlib/GroupTheory/PresentedGroup.lean	1	15	['copilot-pull-request-reviewer', 'euprunin', 'github-actions', 'homeowmorphism', 'mathlib-bors', 'plp127', 'tb65536']	tb65536 assignee:tb65536	8-80707 8 days ago	47-63938 47 days ago	4-29717 4 days
35662	FrankieeW author:FrankieeW	feat(NumberTheory/Zsqrtd): add Archimedean instance via le_arch	This PR follows a suggestion made in #35606 , #35481 - add `Zsqrtd.le_arch_smul` in `Mathlib/NumberTheory/Zsqrtd/Basic.lean` - use it to provide `instance : Archimedean (ℤ√d)` in the `Nonsquare` section - refactor the proof using symmetry to reduce duplication while keeping checks clean --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-number-theory new-contributor awaiting-author merge-conflict LLM-generated	46/4	Mathlib/NumberTheory/PellMatiyasevic.lean,Mathlib/NumberTheory/Zsqrtd/Basic.lean	2	13	['FrankieeW', 'MichaelStollBayreuth', 'euprunin', 'github-actions', 'mathlib-merge-conflicts', 'tb65536']	MichaelStollBayreuth assignee:MichaelStollBayreuth	8-80650 8 days ago	43-7233 43 days ago	15-46568 15 days
34709	dennj author:dennj	feat(Analysis/ODE): add discrete Grönwall inequality	## Summary Add discrete Grönwall inequality to `Mathlib/Analysis/ODE/DiscreteGronwall.lean` Provides bounds for recurrence inequalities of the form `u(n+1) ≤ c(n) * u(n) + b(n)` ### Main results - `discrete_gronwall_prod_general`: Product form working over any linearly ordered commutative ring - `prod_one_add_Ico_mono`: Auxiliary lemma for product comparisons over subintervals - `discrete_gronwall`: Classical exponential bound `u(n) ≤ (u(n₀) + ∑ b(k)) * exp(∑ c(i))` (ℝ-specific) - `discrete_gronwall_Ico`: Uniform bound over a finite interval (ℝ-specific) ## Related work Complements the continuous Grönwall inequality in `Mathlib.Analysis.ODE.Gronwall` ## References * Grönwall, T. H. (1919). "Note on the derivatives with respect to a parameter of the solutions of a system of differential equations". Annals of Mathematics, 20(4), 292–296.	t-analysis new-contributor LLM-generated awaiting-author merge-conflict	174/0	Mathlib.lean,Mathlib/Analysis/ODE/DiscreteGronwall.lean	2	13	['euprunin', 'github-actions', 'grunweg', 'j-loreaux', 'mathlib-merge-conflicts']	j-loreaux assignee:j-loreaux	8-80544 8 days ago	32-67975 32 days ago	46-58371 46 days
34934	zorkary author:zorkary	feat(Data/List): add constructive split classifiers	## Summary This PR adds a small constructive list-classification utility module: - `Mathlib/Data/List/SplitClassify.lean` (new file) - `Mathlib.lean` (one new public import) The goal is to provide reusable case-data classifiers for common split equalities, so downstream proofs can branch on explicit structure instead of repeatedly rebuilding list-shape arguments. ## Added API - `List.append_cons_eq_singleton` - `List.ConsSplit` - `List.classify_cons_vs_split` - `List.SwapSplit` - `List.classify_swap_vs_split` ## Scope and non-goals - No existing theorem statements were changed. - No existing proof logic was modified. - This is a narrow additive change (new module + one import). ## Build I verified: - `lake build Mathlib.Data.List.SplitClassify` ## Duplicate/overlap check Before opening this PR, I checked local mathlib sources and GitHub search for likely overlap, including targeted searches for: - `classify_cons_vs_split` - `classify_swap_vs_split` - `append_cons_eq_singleton` - open PRs/issues around list split/classification helpers I did not find direct existing equivalents or open PRs with the same API. ## AI usage disclosure I used AI assistance (Codex/LLM) for drafting and implementation support. I understand the high-level intent and have validated the module builds. I am opening this as a draft specifically to get maintainer review on technical details before marking it ready.	t-data new-contributor LLM-generated	213/0	Mathlib.lean,Mathlib/Data/List/SplitClassify.lean	2	2	['euprunin', 'github-actions']	nobody	8-80104 8 days ago	unknown	unknown
37062	tannerduve author:tannerduve	feat(Computability): Turing join and semilattice structure on Turing degrees	## Summary - Add `Partrec.kronecker` (equality test) and `Partrec.join` (disjoint union by parity) in `Partrec.lean` - Prove `Nat.RecursiveIn` is closed under computable conditionals (`cond_const`, `cond`) - Show each component reduces to the join (`left_le_join`, `right_le_join`) and the join is the least upper bound (`join_le`) - Establish `SemilatticeSup` instance on `TuringDegree`	t-computability new-contributor large-import	311/15	Mathlib/Computability/Partrec.lean,Mathlib/Computability/RecursiveIn.lean,Mathlib/Computability/TuringDegree.lean	3	5	['Komyyy', 'github-actions', 'mathlib-merge-conflicts', 'tannerduve']	Komyyy assignee:Komyyy	8-65752 8 days ago	8-65069 8 days ago	9-54830 9 days
37279	imalinowskip author:imalinowskip	feat(Probability): multivariate CLT (and Cramèr-Wold)	--- - [x] depends on: #36208 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-measure-probability awaiting-author large-import	500/1	Mathlib.lean,Mathlib/Probability/CentralLimitTheorem.lean,Mathlib/Probability/CramerWold.lean	3	10	['EtienneC30', 'github-actions', 'imalinowskip', 'mathlib-dependent-issues', 'mathlib-merge-conflicts']	RemyDegenne assignee:RemyDegenne	8-64265 8 days ago	13-7431 13 days ago	5-64520 5 days
33032	ksenono author:ksenono	feat(Combinatorics/SimpleGraph): Konig’s theorem on bipartite graphs	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-combinatorics new-contributor blocked-by-other-PR merge-conflict	832/251	Mathlib.lean,Mathlib/Combinatorics/SimpleGraph/Bipartite.lean,Mathlib/Combinatorics/SimpleGraph/Clique.lean,Mathlib/Combinatorics/SimpleGraph/DegreeSum.lean,Mathlib/Combinatorics/SimpleGraph/Konig/Auxillary.lean,Mathlib/Combinatorics/SimpleGraph/Konig/Konig.lean,Mathlib/Combinatorics/SimpleGraph/Konig/KonigFin.lean,Mathlib/Combinatorics/SimpleGraph/Matching.lean,Mathlib/Combinatorics/SimpleGraph/Subgraph.lean,Mathlib/Combinatorics/SimpleGraph/VertexCover.lean,Mathlib/SetTheory/Cardinal/Arithmetic.lean,Mathlib/SetTheory/Cardinal/Basic.lean	12	9	['SnirBroshi', 'github-actions', 'ksenono', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'vlad902']	nobody	8-55212 8 days ago	unknown	unknown
36210	vbeffara author:vbeffara	feat(Combinatorics/SimpleGraph): definitions of graph contraction and graph minor	A contraction is the image of a graph through a surjective function with connected fibers, and a minor is a contraction of a subgraph. This PR shows that being a contraction is transitive, but does not show the same for minors because the proof is more involved, it will be in a subsequent PR. The definitions are in `Prop` and do not contain data, but I'm not sure if that was the right choice. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-combinatorics new-contributor	151/0	Mathlib.lean,Mathlib/Combinatorics/SimpleGraph/Contraction.lean,Mathlib/Combinatorics/SimpleGraph/Minor.lean	3	7	['YaelDillies', 'github-actions', 'mathlib-merge-conflicts', 'vbeffara']	b-mehta assignee:b-mehta	8-50932 8 days ago	34-3895 34 days ago	47-27900 47 days
37350	aditya-ramabadran author:aditya-ramabadran	feat(Analysis/Distribution): define canonical maps between Schwartz/test functions, distributions/tempered distributions	Defines these canonical maps: (1) continuous linear map from $\mathcal D$ to $\mathcal S$, and (2) induced (linear) restriction map from $\mathcal S'$ to $\mathcal D'$, as assigned by @ADedecker. --- Put in a separate file since Distribution.lean only imports TestFunction right now and I thought it was cleaner to do in a new bridge file with both the maps. Open to changing this though. * Made use of #36445 (proved first map locally on fixed support spaces first by local seminorm estimates, then used limitCLM) * Needed a real to complex bridge `TestFunction.ToComplexSchwartzMap` since distributions are defined on real-valued test functions but tempered distributions in mathlib are defined on complex-valued Schwartz functions * Induced map $\mathcal S'(E,F) \to \mathcal D'(Ω,F)$ is $\mathbb C$-linear The main important defs are `ContDiffMapSupportedIn.toSchwartzMapCLM` which is the local fixed-support part, then `TestFunction.toSchwartzMapCLM` (where the continuity uses limitCLM to glue the local continuous linear maps on each $\mathcal D_K$), and `TemperedDistribution.toDistributionLM` which is the linear map from tempered distributions to ordinary distributions. Tested with `lake env lean Mathlib/Analysis/Distribution/TestFunctionSchwartz.lean` [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-analysis new-contributor	279/0	Mathlib.lean,Mathlib/Analysis/Distribution/TestFunctionSchwartz.lean	2	3	['aditya-ramabadran', 'github-actions']	j-loreaux assignee:j-loreaux	7-50967 7 days ago	20-86098 20 days ago	21-36329 21 days
37718	SabrinaJewson author:SabrinaJewson	feat(Order): add conversions from `Std` order typeclasses to Mathlib ones	`{Preorder, PartialOrder, LinearOrder}.ofStd` exist to facilitate convenient translation from `Std` order typeclasses to Mathlib ones. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-order new-contributor	366/0	Mathlib.lean,Mathlib/Order/Std.lean,MathlibTest/OrderOfStd.lean	3	2	['github-actions']	bryangingechen assignee:bryangingechen	7-50963 7 days ago	15-53620 15 days ago	15-53033 15 days
29434	ntapiam author:ntapiam	feat(NonAssoc/LieAdmissible): prove every ring/algebra is LieAdmissible	-awaiting-author	t-algebra new-contributor label:t-algebra$	32/6	Mathlib/Algebra/NonAssoc/LieAdmissible/Defs.lean	1	2	['github-actions', 'mathlib4-merge-conflict-bot']	nobody	7-28106 7 days ago	7-27400 7 days ago	7-26813 7 days
37628	JadAbouHawili author:JadAbouHawili	chore: Rename Xor' to Xor	Rename `Xor'` to `Xor` per the comment which recommended doing so after `v4.25.0-rc1` Moves: - Xor' --> Xor [#new members > Why Xor' and not Xor? Why `Or` and not `OrOp` for `Prop`? @ 💬](https://leanprover.zulipchat.com/#narrow/channel/113489-new-members/topic/Why.20Xor.27.20and.20not.20Xor.3F.20Why.20.60Or.60.20and.20not.20.60OrOp.60.20for.20.60Prop.60.3F/near/583510533) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor	75/66	Mathlib/Algebra/BigOperators/Group/Finset/Basic.lean,Mathlib/Algebra/Ring/Int/Parity.lean,Mathlib/Algebra/Ring/Parity.lean,Mathlib/Data/Bool/Basic.lean,Mathlib/Data/Finset/Basic.lean,Mathlib/Data/Set/Disjoint.lean,Mathlib/Geometry/Manifold/IntegralCurve/ExistUnique.lean,Mathlib/GroupTheory/Index.lean,Mathlib/Logic/Basic.lean,Mathlib/NumberTheory/RatFunc/Ostrowski.lean,Mathlib/Order/SymmDiff.lean,Mathlib/Tactic/ITauto.lean,Mathlib/Topology/Algebra/Order/Archimedean.lean,Mathlib/Topology/Inseparable.lean,Mathlib/Topology/Instances/AddCircle/DenseSubgroup.lean,Mathlib/Topology/Separation/Basic.lean,Mathlib/Topology/Separation/Profinite.lean,MathlibTest/itauto.lean	18	20	['JadAbouHawili', 'Ruben-VandeVelde', 'eric-wieser', 'github-actions', 'grunweg', 'mathlib-merge-conflicts']	nobody	7-3238 7 days ago	7-9280 7 days ago	17-25181 17 days

Stale delegated PRs

Number	Author	Title	Description	Labels	+/-	Modified files (first 100)	📝	💬	All users who commented or reviewed	Assignee(s)	Updated	Last status change	total time in review
25473	adomani author:adomani	feat(CI): check that Mathlib files have lean or md extension	Twice recently there have been files with an "intended" `.lean` extension in `Mathlib/`: * #24942, ending in `;lean`; * #25457, ending in `.Lean`. `mk_all` does not add these files to `Mathlib.lean`, since they do not end in `.lean` and this later causes problems. This CI step checks that all files in `Mathlib/` end with `.lean` or `.md`. See #25474 for a test where the new step [correctly fails](https://github.com/leanprover-community/mathlib4/actions/runs/15464097783/job/43532018379?pr=25474). --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	CI delegated	10/0	.github/workflows/lint_and_suggest_pr.yml	1	10	['adomani', 'bryangingechen', 'github-actions', 'grunweg', 'mathlib-bors']	nobody	321-8578 10 months ago	unknown	unknown
29855	eric-wieser author:eric-wieser	chore(Data/Finset/Sort): lemmas about `0 : Fin _` and `Fin.last _`	We already had these for `⟨0, ⋯⟩` and `⟨k - 1, ⋯⟩`. Moves: - `Finset.orderEmbOfFin_zero` -> `Finset.orderEmbOfFin_mk_zero` - `Finset.orderEmbOfFin_last` -> `Finset.orderEmbOfFin_mk_last` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data t-order delegated easy	17/7	Mathlib/Combinatorics/Enumerative/Composition.lean,Mathlib/Data/Finset/Sort.lean	2	4	['eric-wieser', 'github-actions', 'mathlib-bors', 'ocfnash']	nobody	187-71082 6 months ago	209-16772 209 days ago	3-76820 3 days
27180	ADedecker author:ADedecker	feat: quotient of a monoid with zero by a multiplicative congruence	--- My motivation is getting a more conceptual construction of [ValuativeRel.ValueGroupWithZero](https://leanprover-community.github.io/mathlib4_docs/Mathlib/RingTheory/Valuation/ValuativeRel.html#ValuativeRel.ValueGroupWithZero), but I think this is of independent interest. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict t-algebra delegated label:t-algebra$	141/26	Mathlib.lean,Mathlib/Data/Quot.lean,Mathlib/Data/Setoid/Basic.lean,Mathlib/GroupTheory/Congruence/Defs.lean,Mathlib/GroupTheory/Congruence/GroupWithZero.lean	5	32	['ADedecker', 'eric-wieser', 'github-actions', 'mathlib-bors', 'mathlib4-merge-conflict-bot', 'ocfnash']	ocfnash assignee:ocfnash	173-6271 5 months ago	252-21806 252 days ago	27-80433 27 days
25765	JovanGerb author:JovanGerb	feat(gcongr): lemma for rewriting inside divisibility	TODO: add test to show that we can rewrite using `a ≡ b [ZMOD n]` inside `n ∣ 2 * a + 1`. edit: it's not yet entirely clear if this is the right thing to do. edit: This lemma should be written using iff (or =), so that we can use it specifically when rewriting with a symmetric relation. Supporting equality in `gcongr` is still work in progress. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	delegated t-data	5/0	Mathlib/Data/Int/ModEq.lean	1	3	['fpvandoorn', 'github-actions', 'mathlib-bors']	nobody	159-16273 5 months ago	313-2553 313 days ago	1-17595 1 day
25500	eric-wieser author:eric-wieser	feat: delaborators for metadata	Being able to see these is very important when debugging tactic failures. Probably these could be upstreamed, but I don't think that's a reason not to merge them here first. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import merge-conflict awaiting-author delegated t-meta	75/3	Mathlib/Util/Delaborators.lean,Mathlib/Util/PPOptions.lean,MathlibTest/delaborators.lean	3	19	['JovanGerb', 'Rob23oba', 'eric-wieser', 'github-actions', 'kmill', 'mathlib-bors', 'mathlib4-merge-conflict-bot', 'plp127']	nobody	109-49987 3 months ago	236-80500 236 days ago	42-79607 42 days
27702	FLDutchmann author:FLDutchmann	feat(NumberTheory/SelbergSieve): define Lambda-squared sieves and prove important properties	This PR continues the work from #22052. Original PR: https://github.com/leanprover-community/mathlib4/pull/22052 - [x] depends on: #27820	t-number-theory delegated merge-conflict	186/7	Mathlib/NumberTheory/SelbergSieve.lean	1	44	['FLDutchmann', 'MichaelStollBayreuth', 'bryangingechen', 'github-actions', 'jcommelin', 'mathlib-bors', 'mathlib-merge-conflicts', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	MichaelStollBayreuth assignee:MichaelStollBayreuth	70-31380 2 months ago	132-27425 132 days ago	15-79295 15 days
24965	erdOne author:erdOne	refactor: Make `IsLocalHom` take unbundled map	Under the current definition, `IsLocalHom f` and `IsLocalHom f.toMonoidHom` are not defeq, which causes quite some annoyances. We also have a consensus to not use `*HomClass` in definitions. As a result, we change `IsLocalHom` to take an unbundled function instead of a funlike. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra delegated merge-conflict label:t-algebra$	18/9	Mathlib/Algebra/Group/Units/Hom.lean,Mathlib/AlgebraicGeometry/Scheme.lean,Mathlib/Geometry/RingedSpace/LocallyRingedSpace.lean,Mathlib/Geometry/RingedSpace/OpenImmersion.lean,Mathlib/RingTheory/LocalRing/ResidueField/Basic.lean	5	15	['adomani', 'alreadydone', 'erdOne', 'eric-wieser', 'github-actions', 'jcommelin', 'leanprover-community-bot-assistant', 'mathlib-bors', 'mathlib-merge-conflicts', 'mathlib4-merge-conflict-bot', 'vihdzp']	mattrobball assignee:mattrobball	63-56471 2 months ago	155-22240 155 days ago	14-54827 14 days
34932	erdOne author:erdOne	feat(AlgebraicGeometry): formally etale morphisms	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebraic-geometry merge-conflict delegated	163/12	Mathlib.lean,Mathlib/AlgebraicGeometry/Morphisms/Etale.lean,Mathlib/AlgebraicGeometry/Morphisms/FormallyEtale.lean,Mathlib/AlgebraicGeometry/Morphisms/RingHomProperties.lean,Mathlib/RingTheory/RingHom/Etale.lean	5	17	['chrisflav', 'erdOne', 'github-actions', 'joneugster', 'mathlib-bors', 'mathlib-merge-conflicts', 'ocfnash']	nobody	54-49907 1 month ago	56-58396 56 days ago	11-34462 11 days
25737	robin-carlier author:robin-carlier	feat(AlgebraicTopology/SimplexCategory/GeneratorsRelations/NormalForms): Normal forms for `P_δ`s	We prove that admissible lists indeed provide a normal form for morphisms of satisfying `P_δ`. To this end, we introduce `standardδ`, a construction that takes a list and turn it into a composition of `δ i`s in `SimplexCategoryGenRel`. We then prove that, thanks to the first simplicial identity, composition on the left corresponds to simplicial insertion in the list. This gives existence of a normal form for every morphism satisfying `P_δ`. For unicity, we introduce an auxiliary function `simplicialEvalδ : (List ℕ) → ℕ → ℕ` and show that for admissible lists, it lifts to `ℕ` the `orderHom` attached to `toSimplexCategory.map standardδ`, and that we can recover elements of the list only by looking at values of this function. Part of a series of PR formalising that `SimplexCategoryGenRel` is equivalent to `SimplexCategory`. --- - [x] depends on: #25736 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) --- This PR continues the work from #21746. Original PR: https://github.com/leanprover-community/mathlib4/pull/21746	t-algebraic-topology delegated t-category-theory	181/2	Mathlib/AlgebraicTopology/SimplexCategory/GeneratorsRelations/NormalForms.lean	1	6	['github-actions', 'joelriou', 'mathlib-bors', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	50-82741 1 month ago	183-82468 183 days ago	0-22511 6 hours
35436	daniel-carranza author:daniel-carranza	feat(CategoryTheory/Monoidal/Closed): Prove the isomorphism of internal hom objects C(x \otimes y, z) and C(y, C(x, z))	Prove the currying-uncurrying isomorphism `C(x \otimes y, z) \iso C(y, C(x, z))` between internal hom objects of a closed monoidal category `C`. --- This result is connected to the infinity-cosmos project, and is used to prove that a closed monoidal category enriched in itself admits all cotensors. ~Line 81 currently contains a one-line proof in tactics mode `exact rfl`. When trying to use `rfl` outside of tactics mode, an error is thrown~ (Fixed, thank you @robin-carlier!). Any help with this (or any other aspect of the formalization) is greatly appreciated! [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-category-theory infinity-cosmos delegated	89/0	Mathlib.lean,Mathlib/CategoryTheory/Monoidal/Closed/InternalCurrying.lean	2	15	['dagurtomas', 'daniel-carranza', 'github-actions', 'joelriou', 'mathlib-bors', 'riccardobrasca', 'robin-carlier']	adamtopaz assignee:adamtopaz	46-73297 1 month ago	54-61436 54 days ago	7-65383 7 days
33691	kim-em author:kim-em	feat(scripts): add find-ci-errors.sh to diagnose widespread CI failures	This PR adds a script that searches through recent failed CI workflow runs to find open PRs whose current CI contains a specific error string. Useful for diagnosing widespread CI issues affecting multiple PRs (e.g., infrastructure problems, toolchain bugs). Usage: ```bash # Find all PRs currently failing with a specific error ./scripts/find-ci-errors.sh "Error parsing args: cannot parse arguments" # Find PRs and automatically add please-merge-master label to trigger rebuilds ./scripts/find-ci-errors.sh --please-merge-master "cannot parse arguments" ``` The `--please-merge-master` flag skips PRs with merge conflicts, and the label is automatically removed by CI once the build completes. 🤖 Prepared with Claude Code	CI delegated merge-conflict LLM-generated	196/0	scripts/README.md,scripts/find-ci-errors.sh	2	6	['bryangingechen', 'github-actions', 'mathlib-bors', 'mathlib-merge-conflicts', 'mathlib4-merge-conflict-bot']	nobody	37-354 1 month ago	105-51704 105 days ago	0-6193 1 hour
31092	FlAmmmmING author:FlAmmmmING	feat(Algebra/Group/ForwardDiff.lean): Add theorem `sum_shift_eq_fwdDiff_iter`.	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra new-contributor delegated label:t-algebra$	17/1	Mathlib/Algebra/Group/ForwardDiff.lean	1	20	['BeibeiX0', 'FlAmmmmING', 'Ruben-VandeVelde', 'dagurtomas', 'github-actions', 'jcommelin', 'mathlib-bors', 'mathlib4-merge-conflict-bot']	nobody	34-79969 1 month ago	90-1349 90 days ago	54-13842 54 days
35588	eric-wieser author:eric-wieser	chore(Util/Qq): remove `meta`	These are wrappers of existing functions on `Expr`s which are also not marked `meta`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-meta awaiting-CI delegated	7/7	Mathlib/Data/Multiset/Sort.lean,Mathlib/Tactic/FieldSimp/Lemmas.lean,Mathlib/Tactic/NormNum/Core.lean,Mathlib/Tactic/Order/ToInt.lean,Mathlib/Tactic/Simproc/Divisors.lean,Mathlib/Tactic/Simproc/FinsetInterval.lean,Mathlib/Util/Qq.lean	7	3	['Vierkantor', 'github-actions', 'mathlib-bors']	nobody	34-12663 1 month ago	unknown	unknown
26911	JovanGerb author:JovanGerb	chore: fix naming of `mono` and `monotone`	The naming convention says: "We use `_mono` for `a ≤ b → f a ≤ f b` and `_anti` for `a ≤ b → f b ≤ f a`, so we also use `_monotone` for `Monotone f`, `_antitone` for `Antitone f`, `_strictMono` for `StrictMono f`, `_strictAnti` for `StrictAnti f`, etc..." This PR swaps `mono`/`anti` and `monotone`/`antitone` where required so that `monotone` refers to `Monotone`, while `mono` refers to a lemma that might be tagged with `@[gcongr]` This PR does not address - `monotone_right`/`mono_right` vs `right_monotone`/`right_mono` - `monotone_arcsin` vs `arcsin_monotone` edit: TODO: `ideal_mono` and friends --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	delegated merge-conflict	235/169	Archive/Imo/Imo1962Q1.lean,Archive/Wiedijk100Theorems/AbelRuffini.lean,Archive/Wiedijk100Theorems/SumOfPrimeReciprocalsDiverges.lean,Counterexamples/DiscreteTopologyNonDiscreteUniformity.lean,Mathlib/Algebra/Group/Pointwise/Finset/Basic.lean,Mathlib/Algebra/Group/Pointwise/Set/Basic.lean,Mathlib/Algebra/Order/AddGroupWithTop.lean,Mathlib/Algebra/Order/Field/Basic.lean,Mathlib/Algebra/Order/Group/Basic.lean,Mathlib/Algebra/Order/Group/Finset.lean,Mathlib/Algebra/Order/Group/PosPart.lean,Mathlib/Algebra/Order/GroupWithZero/Unbundled/Basic.lean,Mathlib/Algebra/Order/Monoid/Unbundled/Basic.lean,Mathlib/Algebra/Order/Monoid/Unbundled/Pow.lean,Mathlib/Algebra/Order/ToIntervalMod.lean,Mathlib/Algebra/Polynomial/Degree/CardPowDegree.lean,Mathlib/AlgebraicGeometry/IdealSheaf/Basic.lean,Mathlib/Analysis/Analytic/Composition.lean,Mathlib/Analysis/Convex/Deriv.lean,Mathlib/Analysis/Normed/Order/UpperLower.lean,Mathlib/Analysis/Normed/Unbundled/SeminormFromConst.lean,Mathlib/Analysis/PSeries.lean,Mathlib/Analysis/Real/Pi/Bounds.lean,Mathlib/Analysis/SpecialFunctions/Pow/Continuity.lean,Mathlib/Analysis/SpecialFunctions/Trigonometric/Basic.lean,Mathlib/Analysis/SpecificLimits/Basic.lean,Mathlib/Analysis/SpecificLimits/FloorPow.lean,Mathlib/Combinatorics/SetFamily/Kleitman.lean,Mathlib/Combinatorics/SimpleGraph/Girth.lean,Mathlib/Combinatorics/SimpleGraph/Regularity/Lemma.lean,Mathlib/Data/ENNReal/Inv.lean,Mathlib/Data/ENNReal/Operations.lean,Mathlib/Data/ENat/Pow.lean,Mathlib/Data/Nat/Choose/Factorization.lean,Mathlib/Dynamics/Circle/RotationNumber/TranslationNumber.lean,Mathlib/LinearAlgebra/AffineSpace/AffineMap.lean,Mathlib/MeasureTheory/Constructions/BorelSpace/Basic.lean,Mathlib/MeasureTheory/Constructions/Polish/Basic.lean,Mathlib/MeasureTheory/MeasurableSpace/MeasurablyGenerated.lean,Mathlib/MeasureTheory/OuterMeasure/Operations.lean,Mathlib/NumberTheory/Bertrand.lean,Mathlib/NumberTheory/FermatPsp.lean,Mathlib/NumberTheory/Height/Basic.lean,Mathlib/NumberTheory/ModularForms/Bounds.lean,Mathlib/NumberTheory/Padics/Hensel.lean,Mathlib/NumberTheory/Padics/WithVal.lean,Mathlib/Order/Concept.lean,Mathlib/Order/Filter/AtTopBot/Archimedean.lean,Mathlib/Order/Filter/AtTopBot/Defs.lean,Mathlib/Order/Fin/Basic.lean,Mathlib/Order/Heyting/Basic.lean,Mathlib/Order/Heyting/Boundary.lean,Mathlib/Order/Heyting/Regular.lean,Mathlib/Order/Hom/Set.lean,Mathlib/Order/Interval/Set/Fin.lean,Mathlib/Order/KrullDimension.lean,Mathlib/Order/UpperLower/Closure.lean,Mathlib/Probability/StrongLaw.lean,Mathlib/RingTheory/DedekindDomain/Ideal/Basic.lean,Mathlib/RingTheory/FractionalIdeal/Basic.lean,Mathlib/RingTheory/WittVector/Basic.lean,Mathlib/Topology/EMetricSpace/Lipschitz.lean,Mathlib/Topology/MetricSpace/Antilipschitz.lean	63	11	['JovanGerb', 'bryangingechen', 'github-actions', 'leanprover-community-bot-assistant', 'linesthatinterlace', 'mathlib-bors', 'mathlib-merge-conflicts']	bryangingechen assignee:bryangingechen	28-27105 28 days ago	285-3153 285 days ago	2-48079 2 days
37232	mathlib-splicebot author:mathlib-splicebot	chore(Algebra/Order): bound on `\|n / m\|ₘ` and `\|n - m\|`	This PR was automatically created from PR #34722 by @GrigorenkoPV via a [review comment](https://github.com/leanprover-community/mathlib4/pull/34722#discussion_r2996870566) by @Vierkantor.	t-algebra delegated label:t-algebra$	5/0	Mathlib/Algebra/Order/Group/Unbundled/Abs.lean	1	6	['Vierkantor', 'bryangingechen', 'github-actions', 'mathlib-bors']	nobody	26-62112 26 days ago	unknown	unknown
37507	gasparattila author:gasparattila	chore(Topology/Algebra/Module/Star): tag continuity lemmas with `fun_prop`	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology easy delegated	4/4	Mathlib/Topology/Algebra/Module/Star.lean	1	3	['gasparattila', 'github-actions', 'grunweg', 'mathlib-bors']	nobody	20-79932 20 days ago	20-79932 20 days ago	0-852 14 minutes
31135	kckennylau author:kckennylau	feat(RingTheory): is localization iff is localization on saturation	In this PR we show that `A` is a localization of `R` on the submonoid `S` iff it is so on the saturation of `S`. Crucially, the saturation of `S` is precisely the elements that become a unit in `A`. --- - [x] depends on: #31132 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-ring-theory delegated	53/0	Mathlib.lean,Mathlib/RingTheory/Localization/Saturation.lean	2	15	['alreadydone', 'chrisflav', 'github-actions', 'kckennylau', 'mathlib-bors', 'mathlib-dependent-issues', 'mathlib4-merge-conflict-bot', 'riccardobrasca']	chrisflav assignee:chrisflav	15-18566 15 days ago	15-18567 15 days ago	32-65718 32 days
31607	grunweg author:grunweg	chore: rename `continuous{,On,At,Within}_const` to `ContinuousFoo.const`	Zulip discussion: [#mathlib4 > Naming convention @ 💬](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Naming.20convention/near/447491526) --- - [x] depends on: #34441 - [x] depends on: #34688 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	delegated	412/378	Archive/Hairer.lean,Mathlib/Analysis/Analytic/Basic.lean,Mathlib/Analysis/Analytic/Inverse.lean,Mathlib/Analysis/Asymptotics/Lemmas.lean,Mathlib/Analysis/BoxIntegral/Box/Basic.lean,Mathlib/Analysis/BoxIntegral/UnitPartition.lean,Mathlib/Analysis/CStarAlgebra/ContinuousFunctionalCalculus/Continuity.lean,Mathlib/Analysis/CStarAlgebra/ContinuousFunctionalCalculus/Unital.lean,Mathlib/Analysis/Calculus/BumpFunction/FiniteDimension.lean,Mathlib/Analysis/Calculus/BumpFunction/InnerProduct.lean,Mathlib/Analysis/Calculus/DSlope.lean,Mathlib/Analysis/Calculus/Deriv/MeanValue.lean,Mathlib/Analysis/Calculus/DiffContOnCl.lean,Mathlib/Analysis/Calculus/FDeriv/Analytic.lean,Mathlib/Analysis/Calculus/FDeriv/Symmetric.lean,Mathlib/Analysis/Calculus/MeanValue.lean,Mathlib/Analysis/Calculus/Rademacher.lean,Mathlib/Analysis/Calculus/Taylor.lean,Mathlib/Analysis/Complex/AbelLimit.lean,Mathlib/Analysis/Complex/AbsMax.lean,Mathlib/Analysis/Complex/Basic.lean,Mathlib/Analysis/Complex/CauchyIntegral.lean,Mathlib/Analysis/Complex/HalfPlane.lean,Mathlib/Analysis/Complex/LocallyUniformLimit.lean,Mathlib/Analysis/Complex/PhragmenLindelof.lean,Mathlib/Analysis/Complex/RemovableSingularity.lean,Mathlib/Analysis/Complex/UpperHalfPlane/Basic.lean,Mathlib/Analysis/Complex/UpperHalfPlane/Measure.lean,Mathlib/Analysis/Complex/UpperHalfPlane/Metric.lean,Mathlib/Analysis/Complex/UpperHalfPlane/Topology.lean,Mathlib/Analysis/Convex/Cone/InnerDual.lean,Mathlib/Analysis/Convex/Exposed.lean,Mathlib/Analysis/Convex/Gauge.lean,Mathlib/Analysis/Convex/PartitionOfUnity.lean,Mathlib/Analysis/Convex/Side.lean,Mathlib/Analysis/Convex/StdSimplex.lean,Mathlib/Analysis/Convolution.lean,Mathlib/Analysis/InnerProductSpace/Continuous.lean,Mathlib/Analysis/InnerProductSpace/Harmonic/HarmonicContOnCl.lean,Mathlib/Analysis/InnerProductSpace/LinearPMap.lean,Mathlib/Analysis/InnerProductSpace/MeanErgodic.lean,Mathlib/Analysis/InnerProductSpace/OfNorm.lean,Mathlib/Analysis/LocallyConvex/Separation.lean,Mathlib/Analysis/Meromorphic/Order.lean,Mathlib/Analysis/Meromorphic/TrailingCoefficient.lean,Mathlib/Analysis/Normed/Affine/AddTorsor.lean,Mathlib/Analysis/Normed/Group/Continuity.lean,Mathlib/Analysis/Normed/Group/Lemmas.lean,Mathlib/Analysis/Normed/Module/Ball/Homeomorph.lean,Mathlib/Analysis/Normed/Module/Connected.lean,Mathlib/Analysis/Normed/Module/FiniteDimension.lean,Mathlib/Analysis/Normed/Module/Multilinear/Basic.lean,Mathlib/Analysis/Normed/Operator/Completeness.lean,Mathlib/Analysis/ODE/Gronwall.lean,Mathlib/Analysis/ODE/PicardLindelof.lean,Mathlib/Analysis/RCLike/Basic.lean,Mathlib/Analysis/Seminorm.lean,Mathlib/Analysis/SpecialFunctions/Complex/Arg.lean,Mathlib/Analysis/SpecialFunctions/ContinuousFunctionalCalculus/Rpow/Isometric.lean,Mathlib/Analysis/SpecialFunctions/Elliptic/Weierstrass.lean,Mathlib/Analysis/SpecialFunctions/Gamma/Basic.lean,Mathlib/Analysis/SpecialFunctions/Gamma/Deligne.lean,Mathlib/Analysis/SpecialFunctions/Gaussian/GaussianIntegral.lean,Mathlib/Analysis/SpecialFunctions/Gaussian/PoissonSummation.lean,Mathlib/Analysis/SpecialFunctions/Integrability/Basic.lean,Mathlib/Analysis/SpecialFunctions/Integrals/Basic.lean,Mathlib/Analysis/SpecialFunctions/MulExpNegMulSq.lean,Mathlib/Analysis/SpecialFunctions/PolarCoord.lean,Mathlib/Analysis/SpecialFunctions/Pow/Continuity.lean,Mathlib/Analysis/SpecialFunctions/Pow/Deriv.lean,Mathlib/Analysis/SpecialFunctions/Trigonometric/Basic.lean,Mathlib/Analysis/SpecialFunctions/Trigonometric/Inverse.lean,Mathlib/Computability/AkraBazzi/SumTransform.lean,Mathlib/Condensed/Light/TopCatAdjunction.lean,Mathlib/Condensed/TopCatAdjunction.lean,Mathlib/Dynamics/OmegaLimit.lean,Mathlib/Geometry/Euclidean/Angle/Oriented/Basic.lean,Mathlib/Geometry/Manifold/Bordism.lean,Mathlib/Geometry/Manifold/Complex.lean,Mathlib/Geometry/Manifold/Instances/Icc.lean,Mathlib/Geometry/Manifold/Instances/Real.lean,Mathlib/Geometry/Manifold/SmoothApprox.lean,Mathlib/MeasureTheory/Function/SpecialFunctions/Basic.lean,Mathlib/MeasureTheory/Integral/Bochner/Basic.lean,Mathlib/MeasureTheory/Integral/CircleIntegral.lean,Mathlib/MeasureTheory/Integral/CircleTransform.lean,Mathlib/MeasureTheory/Integral/DominatedConvergence.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral/Basic.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral/FundThmCalculus.lean,Mathlib/MeasureTheory/Integral/RieszMarkovKakutani/Real.lean,Mathlib/MeasureTheory/Measure/LevyProkhorovMetric.lean,Mathlib/MeasureTheory/Measure/Stieltjes.lean,Mathlib/NumberTheory/Cyclotomic/CyclotomicCharacter.lean,Mathlib/NumberTheory/Harmonic/ZetaAsymp.lean,Mathlib/NumberTheory/LSeries/AbstractFuncEq.lean,Mathlib/NumberTheory/LSeries/Deriv.lean,Mathlib/NumberTheory/LSeries/Dirichlet.lean,Mathlib/NumberTheory/LSeries/DirichletContinuation.lean,Mathlib/NumberTheory/LSeries/HurwitzZetaOdd.lean,Mathlib/NumberTheory/LSeries/PrimesInAP.lean	185	14	['github-actions', 'j-loreaux', 'mathlib-bors', 'mathlib-merge-conflicts', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	11-76950 11 days ago	unknown	unknown
37905	j-loreaux author:j-loreaux	feat: turn `ContinuousLinearMapWOT` into a structure	This was previously an `@[irreducible] def`, which is a suboptimal design choice for a type synonym to which you want to transport data-carrying instances. Indeed, in the current state it is quite painful to add `Ring` structure when the domain and codomain coincide, and doing it in the naive (albeit usual) way would immediately lead to diamonds. Therefore, we switch this type synonym to be a one-field structure. In addition, we add `Ring` and `Algebra` instances, generalize the existing `SMul` instances, define `comp`osition of these maps, and prove that `ContinuousLinearMapWOT` forms a semitopological ring (i.e., multiplication is continuous in each variable separately). --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-analysis delegated	314/72	Mathlib/Analysis/LocallyConvex/WeakOperatorTopology.lean	1	3	['dupuisf', 'github-actions', 'mathlib-bors']	dupuisf assignee:dupuisf	10-76367 10 days ago	unknown	unknown
37229	b-mehta author:b-mehta	feat(Algebra/Free): relate the free semigroup and the free monoid	The name is picked to mimic `FreeMagma.toFreeSemigroup`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra delegated label:t-algebra$	100/3	Mathlib.lean,Mathlib/Algebra/Free.lean,Mathlib/Algebra/FreeMonoid/FreeSemigroup.lean	3	9	['adomani', 'b-mehta', 'dagurtomas', 'github-actions', 'mathlib-bors']	dagurtomas assignee:dagurtomas	7-14860 7 days ago	19-70587 19 days ago	7-6561 7 days
35414	joneugster author:joneugster	feat(Cache): Allow arguments of the form `Mathlib.Data.+` which correspond to a folder but not a file	This PR continues the work from #21838. Original PR: https://github.com/leanprover-community/mathlib4/pull/21838	CI t-meta delegated	74/31	Cache/IO.lean,Cache/Main.lean	2	5	['Vierkantor', 'github-actions', 'joneugster', 'mathlib-bors']	nobody	6-79006 6 days ago	unknown	unknown
36867	ADedecker author:ADedecker	feat: line derivative of distributions	--- - [x] depends on: #36866 - [ ] depends on: #38161 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-analysis delegated blocked-by-other-PR	67/3	Mathlib/Analysis/Distribution/Distribution.lean,Mathlib/Topology/Algebra/Module/Spaces/CompactConvergenceCLM.lean	2	7	['ADedecker', 'github-actions', 'j-loreaux', 'mathlib-bors', 'mathlib-dependent-issues', 'mathlib-merge-conflicts']	j-loreaux assignee:j-loreaux	5-3773 5 days ago	14-82992 14 days ago	6-24885 6 days
37889	LLaurance author:LLaurance	chore(Algebra): shorten proof by using tactic mode instead of calc mode	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra delegated label:t-algebra$	4/13	Mathlib/Algebra/Star/Center.lean	1	16	['JovanGerb', 'LLaurance', 'faenuccio', 'github-actions', 'grunweg', 'j-loreaux', 'mathlib-bors', 'themathqueen']	nobody	2-78615 2 days ago	10-83197 10 days ago	1-4037 1 day
31425	robertmaxton42 author:robertmaxton42	feat(Topology): implement delaborators for non-standard topology notation	Add delaborators for unary and binary notation related to non-standard topologies in the TopologicalSpace namespace. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology delegated	274/5	Mathlib.lean,Mathlib/Topology/Defs/Basic.lean,Mathlib/Util/DelabNonCanonical.lean,MathlibTest/Delab/TopologicalSpace.lean	4	72	['Vierkantor', 'eric-wieser', 'github-actions', 'j-loreaux', 'jcommelin', 'kckennylau', 'mathlib-bors', 'robertmaxton42']	alreadydone assignee:alreadydone	2-34684 2 days ago	6-80229 6 days ago	125-29170 125 days