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: December 05, 2025 at 08:15 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
32371	KaiErikNiermann author:KaiErikNiermann	fix: minor error in comment of example for natural transformation	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor easy	1/1	Mathlib/CategoryTheory/NatTrans.lean	1	2	['LLaurance', 'github-actions']	nobody	2-2908 2 days ago	2-3067 2 days ago	2-37944 2 days
32389	LLaurance author:LLaurance	feat(Analysis): Trigonometric identities	`sin` and `cos` of real and complex integer multiples of π/12 --- Resolves https://github.com/leanprover-community/mathlib4/pull/28630#discussion_r2307957255 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)		174/0	Mathlib/Analysis/SpecialFunctions/Trigonometric/Basic.lean	1	1	['github-actions']	nobody	1-78120 1 day ago	1-78120 1 day ago	1-79757 1 day

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
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/)	will-close-soon new-contributor t-analysis awaiting-author WIP help-wanted	411/0	Mathlib/PlaceHolder/ToeplitzHausdorff.lean,Mathlib/PlaceHolder/ToeplitzHausdorff_v2.lean	2	11	['faenuccio', 'ggranberry', 'github-actions']	faenuccio assignee:faenuccio	113-76511 3 months ago	113-76714 3 months ago	4-24257 4 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	t-analysis help-wanted	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	109-42138 3 months ago	122-79423 4 months ago	5-42837 5 days
29634	YaelDillies author:YaelDillies	feat: missing instance `NonUnitalCommSemiring R → NonUnitalNonAssocCommSemiring R`	For some reason, this causes elaboration issues. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra awaiting-CI help-wanted label:t-algebra$	16/7	Mathlib/Algebra/Ring/Defs.lean,Mathlib/RingTheory/Coalgebra/Basic.lean,Mathlib/RingTheory/Coalgebra/Hom.lean,Mathlib/Tactic/Ring/Basic.lean	4	7	['YaelDillies', 'alreadydone', 'github-actions', 'riccardobrasca']	nobody	48-58817 1 month ago	81-81034 2 months ago	0-19 19 seconds
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/)	CI WIP help-wanted	114/0	.github/workflows/mk_windows_bundle.yml,scripts/windowsBundle.bat	2	0	[]	nobody	15-60620 15 days ago	828-29333 2 years ago	0-0 0 seconds
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	11	['YaelDillies', 'adomani', 'github-actions', 'grunweg', 'jcommelin', 'urkud']	nobody	492-66 1 year ago	505-9663 1 year ago	1-73101 1 day
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	t-analysis merge-conflict awaiting-author WIP help-wanted	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	492-63 1 year ago	669-66365 1 year ago	0-0 0 seconds
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/)	t-analysis merge-conflict help-wanted	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	492-62 1 year ago	513-67166 1 year ago	0-0 0 seconds
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/)	awaiting-CI merge-conflict awaiting-author help-wanted	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	492-62 1 year ago	808-54322 2 years ago	0-0 0 seconds
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	t-meta merge-conflict mathlib-port help-wanted	183/0	Mathlib.lean,Mathlib/Data/Rat/MetaDefs.lean,test/rat.lean	3	4	['eric-wieser', 'gebner']	nobody	492-61 1 year ago	661-73450 1 year ago	0-0 0 seconds
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/)	t-topology merge-conflict help-wanted	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	484-74439 1 year ago	484-74439 1 year ago	0-0 0 seconds
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/)	t-number-theory merge-conflict help-wanted	27/0	Mathlib/NumberTheory/NumberField/Basic.lean,Mathlib/RingTheory/IntegralClosure.lean	2	9	['erdOne', 'leanprover-bot', 'mattrobball', 'riccardobrasca', 'xroblot']	nobody	476-76215 1 year ago	476-76215 1 year ago	0-0 0 seconds
14739	urkud author:urkud	feat(Measure): add `gcongr` lemmas	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-measure-probability merge-conflict awaiting-author WIP help-wanted	12/8	Mathlib/MeasureTheory/Covering/Differentiation.lean,Mathlib/MeasureTheory/Function/SimpleFunc.lean,Mathlib/MeasureTheory/Integral/SetToL1.lean,Mathlib/MeasureTheory/Measure/MeasureSpace.lean,Mathlib/Probability/Kernel/Disintegration/Density.lean	5	3	['github-actions', 'kim-em', 'urkud']	nobody	383-84602 1 year ago	383-84602 1 year ago	0-66587 18 hours
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/)	t-algebra t-topology merge-conflict WIP help-wanted 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	308-41660 10 months ago	308-41660 10 months ago	101-64856 101 days
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 t-topology merge-conflict awaiting-author help-wanted	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	203-69515 6 months ago	228-53819 7 months ago	21-25493 21 days
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/)	t-euclidean-geometry merge-conflict awaiting-author help-wanted	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	105-22876 3 months ago	134-57834 4 months ago	0-0 0 seconds
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/)	new-contributor t-analysis merge-conflict WIP help-wanted	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	16-2907 16 days ago	16-2907 16 days ago	0-0 0 seconds
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 t-meta merge-conflict modifies-tactic-syntax awaiting-author help-wanted	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	16-2643 16 days ago	16-2644 16 days ago	0-16 16 seconds
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/)	t-data merge-conflict awaiting-author help-wanted	198/0	Mathlib.lean,Mathlib/Data/Nat/Choose/Wolstenholme.lean	2	4	['github-actions', 'mathlib4-merge-conflict-bot', 'yury-harmonic']	nobody	16-295 16 days ago	16-296 16 days ago	0-125 2 minutes
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/)	t-meta merge-conflict blocked-by-other-PR help-wanted	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	16-2908 16 days ago	16-2909 16 days ago	0-0 0 seconds

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
12936	mattrobball author:mattrobball	chore(Quiver.Opposite): make `Quiver.Hom.op/unop` `abbrev`'s	These are wrappers around the constructor and projection for `Opposite Quiver.Hom _ _`. The projection itself is reducible and with structure eta built in to defeq it seems like we might be making Lean work harder than is necessary. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict	39/34	Mathlib/Algebra/Homology/ShortComplex/Homology.lean,Mathlib/Algebra/Homology/ShortComplex/RightHomology.lean,Mathlib/CategoryTheory/Idempotents/Basic.lean,Mathlib/CategoryTheory/Limits/HasLimits.lean,Mathlib/CategoryTheory/Limits/Opposites.lean,Mathlib/CategoryTheory/Opposites.lean,Mathlib/CategoryTheory/Sites/CoverLifting.lean,Mathlib/CategoryTheory/Subobject/Comma.lean,Mathlib/CategoryTheory/Triangulated/Opposite.lean,Mathlib/Combinatorics/Quiver/Basic.lean	10	9	['YaelDillies', 'kim-em', 'leanprover-bot', 'mattrobball']	nobody	492-66 1 year ago	559-52458 1 year ago	0-0 0 seconds
8788	FMLJohn author:FMLJohn	feat(Algebra/Module/GradeZeroModule): if `A` is a graded semiring and `M` is a graded `A`-module, then each grade of `M` is a module over the 0-th grade of `A`.	--- - [ ] depends on: #8187 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	237/4	Mathlib.lean,Mathlib/Algebra/DirectSum/Internal.lean,Mathlib/Algebra/GradedMonoid.lean,Mathlib/Algebra/Module/GradeZeroModule.lean,Mathlib/RingTheory/GradedAlgebra/Basic.lean,Mathlib/RingTheory/GradedAlgebra/Noetherian.lean	6	4	['FMLJohn', 'github-actions', 'leanprover-community-mathlib4-bot']	nobody	492-63 1 year ago	525-74365 1 year ago	0-0 0 seconds
6777	adomani author:adomani	chore(CovariantClass): replace eta-expanded (· ·), (· + ·), (· ≤ ·), (· < ·)	Replace `CovariantClass X X (· * ·) (· ≤ ·)` with -> `CovariantClass X X HMul.hMul LE.le` and similarly for `HAdd`, `LT`, `Contravariant`. This PR is inspired by [Issue #6646](https://github.com/leanprover-community/mathlib4/issues/6646) and, more specifically, [this comment](https://github.com/leanprover-community/mathlib4/issues/6646#issuecomment-1692792066). Note that https://github.com/leanprover/lean4/pull/2267 would make this unnecessary --- ```bash # First sed command: # the first captured pattern is `CovariantClass ` # the second captured pattern is `` # the third captured pattern is `+` or `` # the fourth captured pattern is `<` or `≤` # a match for `CovariantClass (· ·) (· ·)` becomes # `CovariantClass replaceop replaceop` # Second sed command: similar to the first, but looks for `(Function.swap (· ·))` sed -i ' s=$Co[ntra]variantClass \(..$ \2 \)(· $[+]$ ·) (· $[<≤]$ ·)=\1replaceop\3 replaceop\4=g s=$Co[ntra]variantClass \(..$ \2 \)($[Functio\.swap ]$(· $[+]$ ·)) (· $[<≤]$ ·)=\1(\3replaceop\4) replaceop\5=g s=replaceop+=HAdd.hAdd=g s=replaceop\=HMul.hMul=g s=replaceop<=LT.lt=g s=replaceop≤=LE.le=g s=$Co[ntra]variantClass N N$ (· \ ·) r=\1 HMul.hMul r=g s=$Co[ntra]variantClass N N (swap μ)$ (· ≤ ·)=\1 LE.le=g s=$Co[ntra]variantClass N N$ (swap (· \* ·)) r=\1 (swap HMul.hMul) r=g s=$CovariantClass (Filter α) (Filter α)$ (· / ·) (· ≤ ·)=\1 HDiv.hDiv LE.le=g s=$CovariantClass (Filter α) (Filter α)$ (swap (· / ·)) (· ≤ ·)=\1 (swap HDiv.hDiv) LE.le=g s=$Co[ntra]variantClass . (fun x y .> . \* .)$ (· ≤ ·)=\1 LE.le=g s=$Co[ntra]variantClass . (fun x y .> . \* .)$ (· < ·)=\1 LT.lt=g s=$Co[ntra]variantClass [^}]$ (· ≤ ·)=\1 LE.le=g s=$CovariantClass .* (Filter β)$ (· • ·) LE.le=\1 HSMul.hSMul LE.le=g ' $(git ls-files '*.lean') ``` [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict	703/678	Counterexamples/ZeroDivisorsInAddMonoidAlgebras.lean,Mathlib/Algebra/BigOperators/Basic.lean,Mathlib/Algebra/Bounds.lean,Mathlib/Algebra/CovariantAndContravariant.lean,Mathlib/Algebra/DirectSum/Internal.lean,Mathlib/Algebra/Group/UniqueProds.lean,Mathlib/Algebra/GroupPower/Order.lean,Mathlib/Algebra/MonoidAlgebra/Degree.lean,Mathlib/Algebra/Order/Archimedean.lean,Mathlib/Algebra/Order/Group/Abs.lean,Mathlib/Algebra/Order/Group/Defs.lean,Mathlib/Algebra/Order/Group/DenselyOrdered.lean,Mathlib/Algebra/Order/Group/MinMax.lean,Mathlib/Algebra/Order/Group/OrderIso.lean,Mathlib/Algebra/Order/Hom/Monoid.lean,Mathlib/Algebra/Order/Interval.lean,Mathlib/Algebra/Order/Kleene.lean,Mathlib/Algebra/Order/LatticeGroup.lean,Mathlib/Algebra/Order/Module.lean,Mathlib/Algebra/Order/Monoid/Basic.lean,Mathlib/Algebra/Order/Monoid/Cancel/Defs.lean,Mathlib/Algebra/Order/Monoid/Canonical/Defs.lean,Mathlib/Algebra/Order/Monoid/Defs.lean,Mathlib/Algebra/Order/Monoid/Lemmas.lean,Mathlib/Algebra/Order/Monoid/MinMax.lean,Mathlib/Algebra/Order/Monoid/NatCast.lean,Mathlib/Algebra/Order/Monoid/OrderDual.lean,Mathlib/Algebra/Order/Monoid/Prod.lean,Mathlib/Algebra/Order/Monoid/WithTop.lean,Mathlib/Algebra/Order/Monoid/WithZero/Basic.lean,Mathlib/Algebra/Order/Monoid/WithZero/Defs.lean,Mathlib/Algebra/Order/Nonneg/Ring.lean,Mathlib/Algebra/Order/Pointwise.lean,Mathlib/Algebra/Order/Positive/Ring.lean,Mathlib/Algebra/Order/Ring/Canonical.lean,Mathlib/Algebra/Order/Ring/Defs.lean,Mathlib/Algebra/Order/Ring/Lemmas.lean,Mathlib/Algebra/Order/Sub/Basic.lean,Mathlib/Algebra/Order/Sub/Canonical.lean,Mathlib/Algebra/Order/Sub/Defs.lean,Mathlib/Algebra/Order/WithZero.lean,Mathlib/Algebra/Parity.lean,Mathlib/Algebra/Star/Order.lean,Mathlib/Algebra/Tropical/Basic.lean,Mathlib/Analysis/Normed/Order/Lattice.lean,Mathlib/Data/DFinsupp/Lex.lean,Mathlib/Data/DFinsupp/Order.lean,Mathlib/Data/Finset/Fold.lean,Mathlib/Data/Finsupp/Lex.lean,Mathlib/Data/Finsupp/Order.lean,Mathlib/Data/List/BigOperators/Basic.lean,Mathlib/Data/List/BigOperators/Lemmas.lean,Mathlib/Data/Multiset/Basic.lean,Mathlib/Data/Nat/Cast/Order.lean,Mathlib/Data/PNat/Basic.lean,Mathlib/Data/Real/ENNReal.lean,Mathlib/Data/Real/NNReal.lean,Mathlib/Data/Set/Semiring.lean,Mathlib/Data/Sign.lean,Mathlib/MeasureTheory/Function/LpOrder.lean,Mathlib/MeasureTheory/Function/SimpleFuncDenseLp.lean,Mathlib/MeasureTheory/Measure/MeasureSpace.lean,Mathlib/MeasureTheory/Measure/VectorMeasure.lean,Mathlib/Order/ConditionallyCompleteLattice/Group.lean,Mathlib/Order/Filter/Basic.lean,Mathlib/Order/Filter/Pointwise.lean,Mathlib/Probability/Martingale/Basic.lean,Mathlib/Probability/Process/Stopping.lean,Mathlib/RingTheory/GradedAlgebra/Basic.lean,Mathlib/SetTheory/Cardinal/Basic.lean,Mathlib/SetTheory/Game/Basic.lean,Mathlib/SetTheory/Game/PGame.lean,Mathlib/SetTheory/Ordinal/Arithmetic.lean,Mathlib/SetTheory/Ordinal/Basic.lean,Mathlib/SetTheory/Ordinal/NaturalOps.lean,Mathlib/Tactic/GCongr/Core.lean,Mathlib/Tactic/Positivity/Basic.lean,Mathlib/Topology/ContinuousFunction/Algebra.lean,lean-toolchain,test/Recall.lean,test/propose.lean	81	36	['adomani', 'alreadydone', 'digama0', 'eric-wieser', 'ericrbg', 'jcommelin', 'leanprover-bot', 'sgouezel']	nobody	492-62 1 year ago	513-67166 1 year ago	35-56459 35 days
6491	eric-wieser author:eric-wieser	chore(Mathlib/Algebra/Hom/GroupAction): add `SMulHomClass.comp_smul`	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	24/10	Mathlib/Algebra/Hom/GroupAction.lean	1	0	[]	nobody	492-61 1 year ago	513-67166 1 year ago	83-76369 83 days
10629	madvorak author:madvorak	feat: List.cons_sublist_append_iff_right	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data merge-conflict	11/0	Mathlib/Data/List/Basic.lean	1	1	['eric-wieser']	nobody	477-80006 1 year ago	477-80006 1 year ago	53-73442 53 days
13791	digama0 author:digama0	refactor: Primrec and Partrec	General cleanup of the `Primrec` and `Partrec` files, to better adjust to lean 4 things. The main user-visible change is that `Primrec₂` is no longer a `def` but an `abbrev`, because it was causing inference issues in lean 4. I also removed all the nonterminal `simp`s in `PartrecCode.lean`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	tech debt t-computability merge-conflict	585/778	Mathlib/Computability/Ackermann.lean,Mathlib/Computability/Halting.lean,Mathlib/Computability/Partrec.lean,Mathlib/Computability/PartrecCode.lean,Mathlib/Computability/Primrec.lean	5	2	['github-actions', 'grunweg']	nobody	473-42851 1 year ago	513-67166 1 year ago	1-84718 1 day
11964	adamtopaz author:adamtopaz	feat: The functor of points of a scheme	We construct the functor of points functor, and prove that it's full and faithful. --- - [ ] depends on: #11947 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebraic-geometry t-category-theory merge-conflict	210/0	Mathlib.lean,Mathlib/AlgebraicGeometry/FunctorOfPoints.lean,Mathlib/AlgebraicGeometry/OpenImmersion.lean	3	4	['github-actions', 'grunweg', 'leanprover-community-mathlib4-bot']	nobody	473-42710 1 year ago	513-67166 1 year ago	0-1223 20 minutes
12418	rosborn author:rosborn	style: replace preimage_val with ↓∩ notation	--- This is a rough draft of what the new `↓∩` notation would look like within mathlib. I believe this is an improvement in clarity and would like to have `↓∩` as a standard notation (along with `''`, `⁻¹'`, `↑`, etc...). As `↓∩` is specialized for `Set`s, I have only changed `preimage_val` when the left-hand side of `↓∩` is a `Set`. The introduction of the `↓∩` notation to Data.Set.Image is temporary as it isn't possible to import Data.Set.Subset directly. If we want `↓∩` unscoped, where would be the best place to define it? An option is Data.Set.Defs, but the notation cannot be defined without additional imports as the file does not import `notation3`. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict	56/61	Mathlib/Analysis/InnerProductSpace/Projection.lean,Mathlib/Data/Set/Function.lean,Mathlib/Data/Set/Image.lean,Mathlib/Data/Set/Subset.lean,Mathlib/MeasureTheory/Constructions/Polish.lean,Mathlib/MeasureTheory/MeasurableSpace/Basic.lean,Mathlib/MeasureTheory/Measure/Restrict.lean,Mathlib/Order/UpperLower/Basic.lean,Mathlib/Topology/Bases.lean,Mathlib/Topology/Clopen.lean,Mathlib/Topology/Connected/Basic.lean,Mathlib/Topology/Connected/PathConnected.lean,Mathlib/Topology/Constructions.lean,Mathlib/Topology/ContinuousOn.lean,Mathlib/Topology/LocalAtTarget.lean,Mathlib/Topology/LocallyConstant/Basic.lean,Mathlib/Topology/Separation.lean,Mathlib/Topology/Sober.lean	18	3	['grunweg', 'rosborn']	nobody	473-42609 1 year ago	513-67166 1 year ago	29-14218 29 days
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/)	t-data new-contributor merge-conflict	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	472-63763 1 year ago	477-80005 1 year ago	54-52408 54 days
16464	Parcly-Taxel author:Parcly-Taxel	chore: deprecate `Nat.(case_)strong_induction_on`	…in favour of the now-renamed `Nat.(case)strongInductionOn` in core.	tech debt merge-conflict	54/56	Archive/Imo/Imo1981Q3.lean,Mathlib/Algebra/ContinuedFractions/Computation/Approximations.lean,Mathlib/Algebra/ContinuedFractions/Computation/TerminatesIffRat.lean,Mathlib/Algebra/ContinuedFractions/ConvergentsEquiv.lean,Mathlib/Algebra/Polynomial/Derivative.lean,Mathlib/Algebra/Polynomial/Lifts.lean,Mathlib/Analysis/Analytic/Basic.lean,Mathlib/Analysis/Calculus/ContDiff/Bounds.lean,Mathlib/Analysis/Hofer.lean,Mathlib/Analysis/SpecificLimits/Normed.lean,Mathlib/Combinatorics/Derangements/Finite.lean,Mathlib/Combinatorics/Enumerative/Catalan.lean,Mathlib/Combinatorics/Hall/Finite.lean,Mathlib/Combinatorics/SetFamily/AhlswedeZhang.lean,Mathlib/Computability/Primrec.lean,Mathlib/Data/Fintype/Basic.lean,Mathlib/Data/Fintype/Card.lean,Mathlib/Data/Nat/Choose/Central.lean,Mathlib/Data/Nat/Defs.lean,Mathlib/Data/Nat/Digits.lean,Mathlib/Data/Nat/Log.lean,Mathlib/FieldTheory/Separable.lean,Mathlib/LinearAlgebra/Eigenspace/Triangularizable.lean,Mathlib/LinearAlgebra/Multilinear/Basic.lean,Mathlib/NumberTheory/BernoulliPolynomials.lean,Mathlib/NumberTheory/DiophantineApproximation.lean,Mathlib/NumberTheory/Pell.lean,Mathlib/NumberTheory/Primorial.lean,Mathlib/Order/Fin/Basic.lean,Mathlib/RingTheory/Adjoin/PowerBasis.lean,Mathlib/RingTheory/LittleWedderburn.lean,Mathlib/RingTheory/Polynomial/Basic.lean,Mathlib/RingTheory/Polynomial/Cyclotomic/Basic.lean,Mathlib/RingTheory/Polynomial/Cyclotomic/Eval.lean,Mathlib/RingTheory/Polynomial/Eisenstein/IsIntegral.lean,Mathlib/RingTheory/Polynomial/Nilpotent.lean,Mathlib/RingTheory/PowerSeries/Basic.lean,Mathlib/RingTheory/QuotientNilpotent.lean,Mathlib/RingTheory/WittVector/Defs.lean,Mathlib/RingTheory/WittVector/Frobenius.lean,Mathlib/RingTheory/WittVector/StructurePolynomial.lean,Mathlib/SetTheory/Surreal/Dyadic.lean,Mathlib/Topology/Metrizable/Uniformity.lean	43	13	['Parcly-Taxel', 'b-mehta', 'github-actions', 'jcommelin']	nobody	440-52319 1 year ago	440-52319 1 year ago	8-1989 8 days
17127	FR-vdash-bot author:FR-vdash-bot	chore: remove global `Quotient.mk` `⟦·⟧` notation	--- Merge this PR when we are ready to migrate to `QuotLike` API (#16421). [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data merge-conflict	137/2	Counterexamples/Pseudoelement.lean,Mathlib/Algebra/Associated/Basic.lean,Mathlib/Algebra/BigOperators/Group/Finset.lean,Mathlib/Algebra/Group/Conj.lean,Mathlib/Algebra/GroupWithZero/NonZeroDivisors.lean,Mathlib/Algebra/Order/CauSeq/Completion.lean,Mathlib/Algebra/Quandle.lean,Mathlib/AlgebraicGeometry/EllipticCurve/Jacobian.lean,Mathlib/AlgebraicGeometry/EllipticCurve/Projective.lean,Mathlib/AlgebraicTopology/FundamentalGroupoid/Basic.lean,Mathlib/AlgebraicTopology/FundamentalGroupoid/FundamentalGroup.lean,Mathlib/AlgebraicTopology/FundamentalGroupoid/InducedMaps.lean,Mathlib/AlgebraicTopology/FundamentalGroupoid/Product.lean,Mathlib/AlgebraicTopology/FundamentalGroupoid/SimplyConnected.lean,Mathlib/CategoryTheory/Abelian/Pseudoelements.lean,Mathlib/CategoryTheory/Limits/Shapes/SingleObj.lean,Mathlib/CategoryTheory/Monoidal/Free/Basic.lean,Mathlib/CategoryTheory/Monoidal/Free/Coherence.lean,Mathlib/CategoryTheory/Skeletal.lean,Mathlib/Data/Finset/Card.lean,Mathlib/Data/Fintype/List.lean,Mathlib/Data/Fintype/Quotient.lean,Mathlib/Data/Multiset/Basic.lean,Mathlib/Data/QPF/Multivariate/Constructions/Fix.lean,Mathlib/Data/QPF/Univariate/Basic.lean,Mathlib/Data/Quot.lean,Mathlib/Data/Real/Basic.lean,Mathlib/Data/Set/Finite.lean,Mathlib/Data/Set/Image.lean,Mathlib/Data/Setoid/Basic.lean,Mathlib/GroupTheory/GroupAction/Basic.lean,Mathlib/GroupTheory/GroupAction/Quotient.lean,Mathlib/LinearAlgebra/Dual.lean,Mathlib/LinearAlgebra/Ray.lean,Mathlib/Logic/Encodable/Basic.lean,Mathlib/Logic/Equiv/Basic.lean,Mathlib/ModelTheory/DirectLimit.lean,Mathlib/ModelTheory/Fraisse.lean,Mathlib/ModelTheory/Quotients.lean,Mathlib/NumberTheory/NumberField/CanonicalEmbedding/FundamentalCone.lean,Mathlib/NumberTheory/NumberField/Embeddings.lean,Mathlib/NumberTheory/NumberField/Units/DirichletTheorem.lean,Mathlib/NumberTheory/Padics/PadicIntegers.lean,Mathlib/NumberTheory/Padics/PadicNumbers.lean,Mathlib/Order/RelIso/Basic.lean,Mathlib/RepresentationTheory/Action/Concrete.lean,Mathlib/SetTheory/Cardinal/Basic.lean,Mathlib/SetTheory/Cardinal/Ordinal.lean,Mathlib/SetTheory/Game/Basic.lean,Mathlib/SetTheory/Game/Birthday.lean,Mathlib/SetTheory/Game/Impartial.lean,Mathlib/SetTheory/Game/Ordinal.lean,Mathlib/SetTheory/Game/State.lean,Mathlib/SetTheory/Lists.lean,Mathlib/SetTheory/Ordinal/Arithmetic.lean,Mathlib/SetTheory/Ordinal/Basic.lean,Mathlib/SetTheory/Surreal/Basic.lean,Mathlib/SetTheory/Surreal/Dyadic.lean,Mathlib/SetTheory/Surreal/Multiplication.lean,Mathlib/SetTheory/ZFC/Basic.lean,Mathlib/SetTheory/ZFC/Rank.lean,Mathlib/Topology/Connected/PathConnected.lean,Mathlib/Topology/Homotopy/HomotopyGroup.lean,Mathlib/Topology/Homotopy/Path.lean,Mathlib/Topology/Homotopy/Product.lean,Mathlib/Topology/MetricSpace/GromovHausdorff.lean,Mathlib/Topology/UniformSpace/Separation.lean,test/interactiveUnfold.lean	68	1	['github-actions']	nobody	431-14702 1 year ago	431-14702 1 year ago	4-72805 4 days
8029	alreadydone author:alreadydone	refactor: Homotopy between Functions not ContinuousMaps	This allows talking about homotopies without needing to supply proofs of continuity for the two ends. This for example simplifies the definition of H-spaces. Of course, if a homotopy exists between two functions, those two functions are automatically continuous because they are restrictions of the homotopy (which is continuous) to subspaces. `Homotopy.refl` still needs a continuous map as input, and `Homotopic` is only an equivalence relation when restricted to ContinuousMap. --- TODO: fix docstrings [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology RFC merge-conflict	246/250	Mathlib/AlgebraicTopology/FundamentalGroupoid/InducedMaps.lean,Mathlib/Topology/Homotopy/Basic.lean,Mathlib/Topology/Homotopy/Contractible.lean,Mathlib/Topology/Homotopy/Equiv.lean,Mathlib/Topology/Homotopy/HSpaces.lean,Mathlib/Topology/Homotopy/HomotopyGroup.lean,Mathlib/Topology/Homotopy/Path.lean,Mathlib/Topology/Homotopy/Product.lean	8	3	['alreadydone', 'urkud']	nobody	421-43507 1 year ago	513-67166 1 year ago	9-20043 9 days
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/)	new-contributor t-order t-algebra merge-conflict 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	394-10168 1 year ago	394-10168 1 year ago	7-45599 7 days
12778	MichaelStollBayreuth author:MichaelStollBayreuth	perf: decouple algebraic and order hierarchies in type class search	Based on the experience gained with [#12680](https://github.com/leanprover-community/mathlib4/pull/12680), this attempts to decouple the algebraic and order hierarchies in type class search. * We lower the priorities of instances like `OrderedSemiring.toSemiring` (which are generated by the `extends` clause with default priority 1000) to 50. * Additionally, we make the default priority available via `open scoped AlgebraOrderInstances` and use that where appropriate. Motivation: Looking at instance synthesization traces, it appears that when (e.g.) presented with the goal to find a `Semiring` instance, the algorithm frequently goes down a rabbit hole trying and failing to find order instances. This seems to be caused by the presence of instances like `OrderedSemiring.toSemiring` with default priority, which are tried early in the search, but lead nowhere (after a fairly long time). These instances are created by declarations of the form ```lean class OrderedSemiring (α : Type u) extends Semiring α, OrderedAddCommMonoid α where ... ``` which automatically sets up (among other things) an instance `OrderedSemiring.toSemiring` with default piority. It appears that these instances cannot be removed completely (only locally in a module), so the next best solution is to make them low priority (which is possible also for downstream modules). To provide for situations where these instances are desired, we put a default priority version in the scope `AlgebraOrderInstances`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	slow-typeclass-synthesis t-order t-algebra merge-conflict label:t-algebra$	306/27	Mathlib/Algebra/Algebra/Subalgebra/Order.lean,Mathlib/Algebra/ContinuedFractions/Computation/ApproximationCorollaries.lean,Mathlib/Algebra/ContinuedFractions/Computation/Approximations.lean,Mathlib/Algebra/Module/Rat.lean,Mathlib/Algebra/Module/Submodule/Order.lean,Mathlib/Algebra/Order/AbsoluteValue.lean,Mathlib/Algebra/Order/Algebra.lean,Mathlib/Algebra/Order/Antidiag/Prod.lean,Mathlib/Algebra/Order/Archimedean/Basic.lean,Mathlib/Algebra/Order/BigOperators/Group/Finset.lean,Mathlib/Algebra/Order/BigOperators/Group/List.lean,Mathlib/Algebra/Order/BigOperators/Group/Multiset.lean,Mathlib/Algebra/Order/BigOperators/Ring/Finset.lean,Mathlib/Algebra/Order/BigOperators/Ring/List.lean,Mathlib/Algebra/Order/BigOperators/Ring/Multiset.lean,Mathlib/Algebra/Order/CauSeq/Basic.lean,Mathlib/Algebra/Order/Chebyshev.lean,Mathlib/Algebra/Order/CompleteField.lean,Mathlib/Algebra/Order/Field/Basic.lean,Mathlib/Algebra/Order/Field/Defs.lean,Mathlib/Algebra/Order/Field/Pi.lean,Mathlib/Algebra/Order/Floor.lean,Mathlib/Algebra/Order/Floor/Div.lean,Mathlib/Algebra/Order/Group/Defs.lean,Mathlib/Algebra/Order/Group/Units.lean,Mathlib/Algebra/Order/GroupWithZero/Canonical.lean,Mathlib/Algebra/Order/Hom/Basic.lean,Mathlib/Algebra/Order/Hom/Monoid.lean,Mathlib/Algebra/Order/Interval/Basic.lean,Mathlib/Algebra/Order/Interval/Set/Instances.lean,Mathlib/Algebra/Order/Invertible.lean,Mathlib/Algebra/Order/Kleene.lean,Mathlib/Algebra/Order/Module/Algebra.lean,Mathlib/Algebra/Order/Module/Defs.lean,Mathlib/Algebra/Order/Module/Pointwise.lean,Mathlib/Algebra/Order/Monoid/Basic.lean,Mathlib/Algebra/Order/Monoid/Canonical/Defs.lean,Mathlib/Algebra/Order/Monoid/Defs.lean,Mathlib/Algebra/Order/Monoid/OrderDual.lean,Mathlib/Algebra/Order/Monoid/Prod.lean,Mathlib/Algebra/Order/Nonneg/Field.lean,Mathlib/Algebra/Order/Nonneg/Ring.lean,Mathlib/Algebra/Order/Pi.lean,Mathlib/Algebra/Order/Positive/Field.lean,Mathlib/Algebra/Order/Positive/Ring.lean,Mathlib/Algebra/Order/Rearrangement.lean,Mathlib/Algebra/Order/Ring/Basic.lean,Mathlib/Algebra/Order/Ring/Defs.lean,Mathlib/Algebra/Order/Ring/InjSurj.lean,Mathlib/Algebra/Order/Ring/Pow.lean,Mathlib/Algebra/Order/Sub/WithTop.lean,Mathlib/Algebra/Order/ToIntervalMod.lean,Mathlib/Algebra/Ring/BooleanRing.lean,Mathlib/AlgebraicGeometry/Morphisms/RingHomProperties.lean,Mathlib/AlgebraicTopology/FundamentalGroupoid/Basic.lean,Mathlib/Analysis/BoundedVariation.lean,Mathlib/Analysis/Complex/UpperHalfPlane/Metric.lean,Mathlib/Analysis/Convex/Basic.lean,Mathlib/Analysis/Convex/Cone/Basic.lean,Mathlib/Analysis/Convex/Cone/Closure.lean,Mathlib/Analysis/Convex/Cone/Pointed.lean,Mathlib/Analysis/Convex/Cone/Proper.lean,Mathlib/Analysis/Convex/Exposed.lean,Mathlib/Analysis/Convex/Extrema.lean,Mathlib/Analysis/Convex/Function.lean,Mathlib/Analysis/Convex/Gauge.lean,Mathlib/Analysis/Convex/GaugeRescale.lean,Mathlib/Analysis/Convex/Hull.lean,Mathlib/Analysis/Convex/Join.lean,Mathlib/Analysis/Convex/Mul.lean,Mathlib/Analysis/Convex/Quasiconvex.lean,Mathlib/Analysis/Convex/SpecificFunctions/Pow.lean,Mathlib/Analysis/Convex/Star.lean,Mathlib/Analysis/Convex/Strict.lean,Mathlib/Analysis/InnerProductSpace/Orientation.lean,Mathlib/Analysis/MeanInequalities.lean,Mathlib/Analysis/SpecialFunctions/Gamma/BohrMollerup.lean,Mathlib/Analysis/SpecialFunctions/Polynomials.lean,Mathlib/Analysis/SpecificLimits/FloorPow.lean,Mathlib/Analysis/SpecificLimits/Normed.lean,Mathlib/Combinatorics/Optimization/ValuedCSP.lean,Mathlib/Combinatorics/Pigeonhole.lean,Mathlib/Combinatorics/SetFamily/FourFunctions.lean,Mathlib/Data/DFinsupp/Lex.lean,Mathlib/Data/DFinsupp/Multiset.lean,Mathlib/Data/DFinsupp/Order.lean,Mathlib/Data/Finset/MulAntidiagonal.lean,Mathlib/Data/Finsupp/Lex.lean,Mathlib/Data/Finsupp/Multiset.lean,Mathlib/Data/Finsupp/Order.lean,Mathlib/Data/Int/Log.lean,Mathlib/Data/Multiset/Antidiagonal.lean,Mathlib/Data/Multiset/Basic.lean,Mathlib/Data/Multiset/Bind.lean,Mathlib/Data/Nat/Cast/Field.lean,Mathlib/Data/Nat/Cast/Order/Basic.lean,Mathlib/Data/Nat/Choose/Bounds.lean,Mathlib/Data/PNat/Factors.lean,Mathlib/Data/Rat/Denumerable.lean,Mathlib/Data/Set/Pointwise/Interval.lean	135	34	['MichaelStollBayreuth', 'YaelDillies', 'github-actions', 'leanprover-bot']	nobody	394-9071 1 year ago	394-9071 1 year ago	18-19513 18 days
19212	Julian author:Julian	feat(LinearAlgebra): add a variable_alias for VectorSpace	Taken directly from the variable_alias docs. Zulip: https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/why.20.5Bvariable_alias.5D.20attribute.20is.20not.20used.20in.20Mathlib.3F --- This is the first actual variable alias added to mathlib. I haven't reviewed variable_alias fully, but it seems like there's at least 3 ways they could be distributed in Mathlib: * alongside whatever subfolder they "belong to" (which is what I've tentatively done here) * In a file called `Aliases` somewhere near the thing they alias (which seems less discoverable to me) * In a single file, a la `Mathlib.TrainingWheels` (with some less playful name) which is meant to define a bunch of more "friendly" aliases all in one place. I kind of like the idea of the third thing as a future module but perhaps it can be synthesized if/when there are more aliases? For now as I say I've done the first one, but please let me know if someone prefers something else. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	25/0	Mathlib.lean,Mathlib/LinearAlgebra/VectorSpace.lean,scripts/noshake.json	3	10	['Julian', 'PieterCuijpers', 'github-actions', 'urkud']	nobody	373-73323 1 year ago	373-73323 1 year ago	7-68492 7 days
19337	zeramorphic author:zeramorphic	feat(Data/Finsupp): generalise `Finsupp` to any "zero" value	Remove the explicit dependence of `Finsupp` on `[Zero M]`, instead defining `Finsupp'` (better name pending) to be functions that are equal to a fixed value `z : M` cofinitely often. This PR is intended to do the initial work of replacing the definition of `Finsupp` with an instantiation of the more general definition, without adding any appropriate API. If accepted, the API development will follow in later PRs. Issues to consider: - Naming of `Finsupp'.` - Where should `Finsupp'` lemmas go? Do they need their own file/folder under `Data/`? Relevant Zulip threads: - https://leanprover.zulipchat.com/#narrow/channel/217875-Is-there-code-for-X.3F/topic/Finsupp.20generalisations - https://leanprover.zulipchat.com/#narrow/channel/217875-Is-there-code-for-X.3F/topic/Finsupp-like.20partial.20function Comments are welcome. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data merge-conflict	203/83	Archive/Wiedijk100Theorems/Partition.lean,Mathlib/Algebra/MvPolynomial/Basic.lean,Mathlib/Algebra/MvPolynomial/Rename.lean,Mathlib/Algebra/MvPolynomial/Variables.lean,Mathlib/Algebra/Polynomial/Basic.lean,Mathlib/Algebra/Polynomial/Laurent.lean,Mathlib/Data/Finsupp/BigOperators.lean,Mathlib/Data/Finsupp/Defs.lean,Mathlib/Data/Finsupp/Order.lean,Mathlib/Data/Nat/Choose/Multinomial.lean,Mathlib/RingTheory/MvPolynomial/Symmetric/Defs.lean,Mathlib/RingTheory/PowerBasis.lean,scripts/nolints_prime_decls.txt	13	5	['github-actions', 'vihdzp', 'zeramorphic']	nobody	371-49400 1 year ago	371-49400 1 year ago	4-60621 4 days
18756	astrainfinita author:astrainfinita	refactor: deprecate `DistribMulActionSemiHomClass` `MulSemiringActionSemiHomClass`	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	50/28	Mathlib/Algebra/Algebra/NonUnitalHom.lean,Mathlib/Algebra/Module/LinearMap/Defs.lean,Mathlib/GroupTheory/GroupAction/Hom.lean	3	4	['astrainfinita', 'github-actions', 'leanprover-bot']	nobody	360-15069 11 months ago	360-15069 11 months ago	31-75259 31 days
18748	FR-vdash-bot author:FR-vdash-bot	refactor: deprecate `ContinuousLinearMapClass`	--- - [ ] depends on: #18689 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra t-topology merge-conflict label:t-algebra$	115/49	Mathlib/Analysis/CStarAlgebra/Spectrum.lean,Mathlib/Analysis/LocallyConvex/WeakOperatorTopology.lean,Mathlib/Analysis/Normed/Algebra/Spectrum.lean,Mathlib/Analysis/Normed/Operator/LinearIsometry.lean,Mathlib/Topology/Algebra/Module/Basic.lean,Mathlib/Topology/Algebra/Module/CharacterSpace.lean,Mathlib/Topology/Algebra/Module/FiniteDimension.lean,Mathlib/Topology/Algebra/Module/StrongTopology.lean,Mathlib/Topology/Algebra/Module/WeakDual.lean,Mathlib/Topology/Homeomorph.lean	10	5	['FR-vdash-bot', 'github-actions', 'leanprover-bot', 'mathlib4-dependent-issues-bot']	nobody	353-65482 11 months ago	353-65485 11 months ago	0-989 16 minutes
18474	FR-vdash-bot author:FR-vdash-bot	perf: lower the priority of `WithOne.to` instances	--- From #7873. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data slow-typeclass-synthesis t-algebra merge-conflict label:t-algebra$	9/2	Mathlib/Algebra/Polynomial/BigOperators.lean,Mathlib/Data/Int/Cast/Defs.lean,Mathlib/Data/Nat/Cast/Defs.lean	3	7	['FR-vdash-bot', 'eric-wieser', 'github-actions', 'leanprover-bot']	nobody	323-49305 10 months ago	323-49305 10 months ago	76-67978 76 days
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/)	new-contributor t-measure-probability merge-conflict	203/40	Mathlib/MeasureTheory/Function/LpSeminorm/CompareExp.lean,Mathlib/MeasureTheory/Function/LpSpace.lean	2	1	['github-actions']	nobody	310-73562 10 months ago	310-73562 10 months ago	27-43617 27 days
16314	FR-vdash-bot author:FR-vdash-bot	chore(Data/Quot): deprecate `ind*'` APIs	--- - [x] depends on: #16264 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data merge-conflict	247/287	Counterexamples/CliffordAlgebraNotInjective.lean,Mathlib/Algebra/Colimit/Module.lean,Mathlib/Algebra/Lie/Quotient.lean,Mathlib/Algebra/Module/Torsion.lean,Mathlib/Algebra/RingQuot.lean,Mathlib/Analysis/SpecialFunctions/Trigonometric/Angle.lean,Mathlib/CategoryTheory/ConnectedComponents.lean,Mathlib/CategoryTheory/Subobject/Basic.lean,Mathlib/CategoryTheory/Subobject/FactorThru.lean,Mathlib/CategoryTheory/Subobject/Lattice.lean,Mathlib/Computability/Reduce.lean,Mathlib/Computability/Tape.lean,Mathlib/Data/List/Cycle.lean,Mathlib/Data/Multiset/MapFold.lean,Mathlib/Data/Multiset/ZeroCons.lean,Mathlib/Data/Quot.lean,Mathlib/Data/Setoid/Basic.lean,Mathlib/Data/Setoid/Partition.lean,Mathlib/FieldTheory/Fixed.lean,Mathlib/GroupTheory/Complement.lean,Mathlib/GroupTheory/Congruence/Basic.lean,Mathlib/GroupTheory/Congruence/Defs.lean,Mathlib/GroupTheory/Congruence/Hom.lean,Mathlib/GroupTheory/Coset/Basic.lean,Mathlib/GroupTheory/Coset/Defs.lean,Mathlib/GroupTheory/FreeAbelianGroup.lean,Mathlib/GroupTheory/GroupAction/Basic.lean,Mathlib/GroupTheory/GroupAction/Defs.lean,Mathlib/GroupTheory/GroupAction/Quotient.lean,Mathlib/GroupTheory/Index.lean,Mathlib/GroupTheory/MonoidLocalization/Basic.lean,Mathlib/GroupTheory/PGroup.lean,Mathlib/GroupTheory/Perm/Cycle/Concrete.lean,Mathlib/GroupTheory/PresentedGroup.lean,Mathlib/GroupTheory/QuotientGroup/Basic.lean,Mathlib/GroupTheory/QuotientGroup/Defs.lean,Mathlib/GroupTheory/SchurZassenhaus.lean,Mathlib/GroupTheory/Sylow.lean,Mathlib/LinearAlgebra/Alternating/DomCoprod.lean,Mathlib/LinearAlgebra/Projectivization/Basic.lean,Mathlib/LinearAlgebra/Quotient/Basic.lean,Mathlib/LinearAlgebra/Quotient/Defs.lean,Mathlib/MeasureTheory/Function/AEEqFun.lean,Mathlib/NumberTheory/Padics/PadicNumbers.lean,Mathlib/NumberTheory/RamificationInertia/Basic.lean,Mathlib/Order/Antisymmetrization.lean,Mathlib/Order/Category/PartOrd.lean,Mathlib/Order/Filter/Germ/Basic.lean,Mathlib/RepresentationTheory/GroupCohomology/Hilbert90.lean,Mathlib/RingTheory/AdicCompletion/Algebra.lean,Mathlib/RingTheory/AdicCompletion/Basic.lean,Mathlib/RingTheory/AdicCompletion/Functoriality.lean,Mathlib/RingTheory/AdjoinRoot.lean,Mathlib/RingTheory/Congruence/Basic.lean,Mathlib/RingTheory/Flat/FaithfullyFlat/Basic.lean,Mathlib/RingTheory/GradedAlgebra/HomogeneousLocalization.lean,Mathlib/RingTheory/Ideal/Cotangent.lean,Mathlib/RingTheory/Ideal/Norm/AbsNorm.lean,Mathlib/RingTheory/Ideal/Quotient/Basic.lean,Mathlib/RingTheory/Ideal/Quotient/Defs.lean,Mathlib/RingTheory/Ideal/Quotient/Operations.lean,Mathlib/RingTheory/Valuation/Quotient.lean,Mathlib/Topology/Algebra/Group/TopologicalAbelianization.lean,Mathlib/Topology/Algebra/InfiniteSum/Module.lean,Mathlib/Topology/Separation/Basic.lean	65	4	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	234-6549 7 months ago	234-6551 7 months ago	55-52030 55 days
15483	FR-vdash-bot author:FR-vdash-bot	chore(GroupTheory/Coset): reduce defeq abuse	--- - [x] depends on: #15482 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	114/60	Mathlib/GroupTheory/Commensurable.lean,Mathlib/GroupTheory/Coset.lean,Mathlib/GroupTheory/QuotientGroup.lean,Mathlib/LinearAlgebra/Alternating/DomCoprod.lean,Mathlib/MeasureTheory/Measure/Haar/Quotient.lean,Mathlib/Topology/Algebra/Group/Compact.lean	6	14	['FR-vdash-bot', 'eric-wieser', 'github-actions', 'grunweg', 'leanprover-bot', 'leanprover-community-mathlib4-bot', 'mattrobball', 'mergify', 'urkud']	nobody	233-37842 7 months ago	481-76172 1 year ago	4-79214 4 days
13649	FR-vdash-bot author:FR-vdash-bot	chore: redefine `Nat.div2` `Nat.bodd`	The new definitions are faster than the old ones. `Nat.binaryRec` will be moved to batteries (https://github.com/leanprover-community/batteries/pull/799) or core (https://github.com/leanprover/lean4/pull/3756), so relevant contents are moved to a new file temporarily. --- - [x] depends on: #15567 - [x] depends on: #19666 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict	63/88	Mathlib/Computability/Primrec.lean,Mathlib/Data/Int/Bitwise.lean,Mathlib/Data/Nat/Bits.lean,Mathlib/Data/Nat/Bitwise.lean,Mathlib/Data/Nat/Size.lean,Mathlib/Logic/Denumerable.lean,Mathlib/Logic/Encodable/Basic.lean,Mathlib/Logic/Equiv/Nat.lean	8	15	['FR-vdash-bot', 'digama0', 'eric-wieser', 'github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'urkud']	digama0 assignee:digama0	216-29881 7 months ago	216-29883 7 months ago	87-51692 87 days
4979	mhk119 author:mhk119	doc(Data/Nat/Bitblast): initial commit	Initial commit of Bitblast.lean where we prove equivalence of bitblast unsigned less than and bitblast addition. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data merge-conflict	202/4	Mathlib/Data/Bool/Basic.lean,Mathlib/Data/Nat/Bitwise.lean,Mathlib/Data/Nat/Pow.lean	3	49	['ChrisHughes24', 'digama0', 'goens', 'grunweg', 'j-loreaux', 'kim-em', 'mhk119']	nobody	216-1716 7 months ago	216-1716 7 months ago	7-68358 7 days
18441	ADedecker author:ADedecker	refactor(AdicTopology): use new API for algebraic filter bases, and factor some code	--- - [x] depends on: #18437 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra t-topology merge-conflict label:t-algebra$	847/159	Mathlib.lean,Mathlib/Topology/Algebra/FilterBasis.lean,Mathlib/Topology/Algebra/FilterBasisNew.lean,Mathlib/Topology/Algebra/Nonarchimedean/AdicTopology.lean,Mathlib/Topology/Algebra/Nonarchimedean/Bases.lean,Mathlib/Topology/Algebra/Nonarchimedean/BasesNew.lean	6	3	['ADedecker', 'github-actions', 'mathlib4-dependent-issues-bot']	nobody	168-67649 5 months ago	168-67651 5 months ago	0-679 11 minutes
18439	ADedecker author:ADedecker	refactor: use new algebraic filter bases API in `FiniteAdeleRing`	--- - [x] depends on: #18437 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra t-topology merge-conflict label:t-algebra$	699/21	Mathlib.lean,Mathlib/RingTheory/DedekindDomain/FiniteAdeleRing.lean,Mathlib/Topology/Algebra/FilterBasis.lean,Mathlib/Topology/Algebra/FilterBasisNew.lean,Mathlib/Topology/Algebra/Nonarchimedean/Bases.lean,Mathlib/Topology/Algebra/Nonarchimedean/BasesNew.lean	6	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	168-67647 5 months ago	168-67649 5 months ago	0-619 10 minutes
18438	ADedecker author:ADedecker	refactor: adapt `KrullTopology` to the new algebraic filter bases API	--- - [x] depends on: #18437 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra t-topology merge-conflict label:t-algebra$	771/168	Mathlib.lean,Mathlib/FieldTheory/KrullTopology.lean,Mathlib/Topology/Algebra/FilterBasis.lean,Mathlib/Topology/Algebra/FilterBasisNew.lean,Mathlib/Topology/Algebra/Nonarchimedean/Bases.lean,Mathlib/Topology/Algebra/Nonarchimedean/BasesNew.lean	6	5	['ADedecker', 'AntoineChambert-Loir', 'github-actions', 'mathlib4-dependent-issues-bot']	nobody	168-67646 5 months ago	168-67647 5 months ago	0-638 10 minutes
13964	pechersky author:pechersky	feat(Data/DigitExpansion): begin defining variant of reals without rationals	Based on a de Bruijn 1976 paper. This file is just the basic definition of a digit expansion. Will be followed up with further constructions. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data merge-conflict	518/0	Mathlib.lean,Mathlib/Data/DigitExpansion/Defs.lean,docs/references.bib	3	11	['eric-wieser', 'github-actions', 'kim-em', 'pechersky']	dupuisf assignee:dupuisf	165-49937 5 months ago	403-76153 1 year ago	129-57991 129 days
16074	Rida-Hamadani author:Rida-Hamadani	feat: combinatorial maps and planar graphs	We define combinatorial maps, then we define planar graph using combinatorial maps. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-combinatorics merge-conflict	243/0	Mathlib.lean,Mathlib/Combinatorics/SimpleGraph/Planar.lean,Mathlib/Data/CombinatorialMap.lean	3	28	['Parcly-Taxel', 'Rida-Hamadani', 'github-actions', 'lambda-fairy', 'leanprover-community-bot-assistant']	kmill assignee:kmill	153-15512 5 months ago	153-15513 5 months ago	72-51453 72 days
7596	alreadydone author:alreadydone	feat: covering maps from properly discontinuous actions and discrete subgroups	--- - [x] depends on: #23236 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	file-removed t-topology merge-conflict	350/21	Mathlib.lean,Mathlib/Analysis/SpecialFunctions/Complex/Circle.lean,Mathlib/Topology/Algebra/ConstMulAction.lean,Mathlib/Topology/Algebra/Group/Pointwise.lean,Mathlib/Topology/Covering/AddCircle.lean,Mathlib/Topology/Covering/Basic.lean,Mathlib/Topology/Covering/Galois.lean,Mathlib/Topology/Homotopy/Lifting.lean,Mathlib/Topology/Instances/AddCircle/Defs.lean	9	18	['ADedecker', 'alreadydone', 'digama0', 'github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'tb65536']	nobody	152-52615 4 months ago	152-52616 4 months ago	73-67280 73 days
11632	mattrobball author:mattrobball	chore(Group/RingTheory.Congruence): make `Quotient`'s reducible	These are essentially wrappers and should not expose any data when made reducible. Their use in constructing typeclass instances makes reducible transparency desirable. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-group-theory merge-conflict	16/35	Mathlib/GroupTheory/Congruence/Basic.lean,Mathlib/RingTheory/Congruence/Basic.lean	2	14	['eric-wieser', 'fpvandoorn', 'github-actions', 'grunweg', 'kmill', 'leanprover-bot', 'mattrobball']	nobody	122-79026 4 months ago	122-79026 4 months ago	2-10495 2 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 --- - [ ] depends on:#18728 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-ring-theory merge-conflict	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	121-81001 3 months ago	121-81001 3 months ago	172-57747 172 days
19097	Vierkantor author:Vierkantor	chore(Algebra.Polynomial): split `Polynomial/Basic.lean` into smaller files	This PR splits `Mathlib.Algebra.Polynomial.Basic` into the following files: * `Polynomial/Defs.lean`: definition and ring structure on `R[X]` * `Polynomial/Module.lean`: module structure on `R[X]` * `Polynomial/Monomial.lean`: merged definition of `monomial`, `X`, `C` into the existing file (this is probably the file you want to import from now on) * `Polynomial/EraseUpdate.lean`: definition of `erase` and `update` * `Polynomial/Sum.lean`: definition of `sum` Initially I added the monomial results to a new file, but ended up merging it with `Monomial.lean` since the two of them merge cleanly. --- - [x] depends on: #28030 (going to resurrect this PR on top of that one later) - [x] depends on: #19095 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	3109/2500	Mathlib.lean,Mathlib/Algebra/BigOperators/Finsupp.lean,Mathlib/Algebra/MonoidAlgebra/Basic.lean,Mathlib/Algebra/MonoidAlgebra/Defs.lean,Mathlib/Algebra/MonoidAlgebra/Division.lean,Mathlib/Algebra/MonoidAlgebra/Lift.lean,Mathlib/Algebra/MonoidAlgebra/MapDomain.lean,Mathlib/Algebra/MonoidAlgebra/Module.lean,Mathlib/Algebra/MonoidAlgebra/Opposite.lean,Mathlib/Algebra/MonoidAlgebra/Support.lean,Mathlib/Algebra/Polynomial/Basic.lean,Mathlib/Algebra/Polynomial/Cardinal.lean,Mathlib/Algebra/Polynomial/Coeff.lean,Mathlib/Algebra/Polynomial/Defs.lean,Mathlib/Algebra/Polynomial/Degree/Definitions.lean,Mathlib/Algebra/Polynomial/Degree/TrailingDegree.lean,Mathlib/Algebra/Polynomial/EraseUpdate.lean,Mathlib/Algebra/Polynomial/Eval/Defs.lean,Mathlib/Algebra/Polynomial/Eval/Degree.lean,Mathlib/Algebra/Polynomial/Module.lean,Mathlib/Algebra/Polynomial/Monomial.lean,Mathlib/Algebra/Polynomial/Sum.lean,Mathlib/Data/Finsupp/Basic.lean,Mathlib/Data/Finsupp/Defs.lean,Mathlib/Data/Finsupp/Ext.lean,Mathlib/Data/Finsupp/Fintype.lean,Mathlib/Data/Finsupp/Indicator.lean,Mathlib/Data/Finsupp/Notation.lean,Mathlib/Data/Finsupp/Pointwise.lean,Mathlib/Data/Finsupp/SMulWithZero.lean,Mathlib/Data/Finsupp/Single.lean,Mathlib/Data/List/ToFinsupp.lean,Mathlib/LinearAlgebra/Matrix/Charpoly/Eigs.lean,Mathlib/RingTheory/KrullDimension/Basic.lean,Mathlib/RingTheory/Polynomial/Opposites.lean,Mathlib/RingTheory/PowerSeries/Basic.lean,Mathlib/Tactic/ExtractGoal.lean,MathlibTest/Polynomial.lean,MathlibTest/instance_diamonds.lean,scripts/noshake.json	40	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	107-74585 3 months ago	113-67370 3 months ago	0-0 0 seconds
13795	astrainfinita author:astrainfinita	perf(Algebra/{Group, GroupWithZero, Ring}/InjSurj): reduce everything	--- - [ ] depends on: #15192 - [ ] depends on: #15476 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	340/194	Mathlib/Algebra/Equiv/TransferInstance.lean,Mathlib/Algebra/Group/InjSurj.lean,Mathlib/Algebra/GroupWithZero/Action/Defs.lean,Mathlib/Algebra/GroupWithZero/Action/End.lean,Mathlib/Algebra/GroupWithZero/InjSurj.lean,Mathlib/Algebra/Module/Defs.lean,Mathlib/Algebra/Module/RingHom.lean,Mathlib/Algebra/Ring/InjSurj.lean,scripts/noshake.json	9	37	['MichaelStollBayreuth', 'astrainfinita', 'eric-wieser', 'github-actions', 'leanprover-bot', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mattrobball']	nobody	104-70261 3 months ago	233-85266 7 months ago	52-31623 52 days
6993	jjaassoonn author:jjaassoonn	feat: lemmas about `AddMonoidAlgebra.{divOf, modOf}`	--- - [x] depends on: #7582 - [x] depends on: #8975 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	147/3	Mathlib/Algebra/MonoidAlgebra/Division.lean,Mathlib/Data/Finsupp/Basic.lean,Mathlib/Data/MvPolynomial/Basic.lean,Mathlib/Data/MvPolynomial/CommRing.lean,Mathlib/Data/MvPolynomial/Division.lean	5	42	['YaelDillies', 'alreadydone', 'digama0', 'eric-wieser', 'github-actions', 'jjaassoonn', 'leanprover-community-mathlib4-bot']	nobody	15-60615 15 days ago	513-67166 1 year ago	102-21189 102 days
9339	FMLJohn author:FMLJohn	feat(RingTheory/GradedAlgebra/HomogeneousIdeal): given a finitely generated homogeneous ideal of a graded semiring, construct a finite spanning set for the ideal which only contains homogeneous elements	--- - [ ] depends on: #8187 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-ring-theory merge-conflict	402/4	Mathlib.lean,Mathlib/Algebra/DirectSum/Internal.lean,Mathlib/Algebra/GradedMonoid.lean,Mathlib/Algebra/Module/GradeZeroModule.lean,Mathlib/RingTheory/Finiteness.lean,Mathlib/RingTheory/GradedAlgebra/Basic.lean,Mathlib/RingTheory/GradedAlgebra/HomogeneousIdeal.lean,Mathlib/RingTheory/GradedAlgebra/Noetherian.lean	8	11	['FMLJohn', 'github-actions', 'jjaassoonn', 'leanprover-community-mathlib4-bot']	nobody	15-60568 15 days ago	121-80994 3 months ago	0-0 0 seconds
14089	callesonne author:callesonne	feat(Bicategory/Functorbicategory): define bicategory of pseudofunctors	This PR contains a definition of the bicategory of pseudofunctors, in the file `Bicategory/FunctorBicategory/Pseudo.lean`. It also moves the file `Bicategory/Functorbicategory.lean` to `Bicategory/FunctorBicategory/Oplax.lean`. --- - [x] depends on: #14028 - [x] depends on: #18250 - [x] depends on: #18252 - [x] depends on: #18253 - [ ] depends on: #18254 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-category-theory merge-conflict	385/70	Mathlib.lean,Mathlib/CategoryTheory/Bicategory/FunctorBicategory/Oplax.lean,Mathlib/CategoryTheory/Bicategory/FunctorBicategory/Pseudo.lean,Mathlib/CategoryTheory/Bicategory/Modification/Oplax.lean,Mathlib/CategoryTheory/Bicategory/Modification/Pseudo.lean,Mathlib/CategoryTheory/Bicategory/NaturalTransformation/Oplax.lean,Mathlib/CategoryTheory/Bicategory/NaturalTransformation/Pseudo.lean	7	6	['callesonne', 'github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	3-38836 3 days ago	3-38838 3 days ago	9-2320 9 days
20527	trivial1711 author:trivial1711	refactor(Topology/UniformSpace/Completion): more descriptive names for `α → Completion α`	- We rename the various maps `α → Completion α` in order to make their names more consistent. - Let `α` be a uniform space. We rename the uniformly continuous function `α → Completion α` from `UniformSpace.Completion.coe'` to `UniformSpace.Completion.coe`. - Let `α` be a uniform additive group. We rename the additive group homomorphism `α →+ Completion α` from `UniformSpace.Completion.toCompl` to `UniformSpace.Completion.coeAddHom`. - Let `α` be a uniform ring. The ring homomorphism `α →+* Completion α` is called `UniformSpace.Completion.coeRingHom`; its name is unchanged. - Let `α` be a normed space over a field `𝕜`. We rename the linear isometry `α →ₗᵢ[𝕜] Completion α` from `UniformSpace.Completion.toComplₗᵢ` to `UniformSpace.Completion.coeₗᵢ`. - Let `α` be a normed space over a field `𝕜`. We rename the continuous linear map `α →L[𝕜] Completion α` from `UniformSpace.Completion.toComplL` to `UniformSpace.Completion.coeL`. - Let `α` be a normed additive group. We rename the norm preserving homomorphism `NormedAddGroupHom α (Completion α)` from `NormedAddCommGroup.toCompl` to `UniformSpace.Completion.coeNormedAddGroupHom`. - We analogously rename some other theorems. - We add some trivial theorems (all of which are proved by `rfl`) that state that the functions considered above are equal. We give all of them the `simp` and `norm_cast` attributes. - We add a new theorem `UniformSpace.Completion.coeAddHom_eq_coe` that states that `UniformSpace.Completion.coeAddHom` and `UniformSpace.Completion.coe` are equal as functions. - We similarly add a new theorem `UniformSpace.Completion.coeRingHom_eq_coe`. - We rename the theorem `UniformSpace.Completion.coe_toComplₗᵢ` to `UniformSpace.Completion.coeₗᵢ_eq_coe`. - We rename the theorem `UniformSpace.Completion.coe_toComplL` to `UniformSpace.Completion.coeL_eq_coe`. - We similarly add a new theorem `UniformSpace.Completion.coeNormedAddGroupHom_eq_coe`. - We change all occurrences of the string `((↑) : α → Completion α)` to `(coe : α → Completion α)` or just `coe`. - We put the statements of some theorems into simp normal form by using the plain function `coe` rather than the homomorphisms that carry more structure. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology merge-conflict	130/92	Mathlib/Analysis/Analytic/Uniqueness.lean,Mathlib/Analysis/Calculus/FDeriv/Analytic.lean,Mathlib/Analysis/Complex/AbsMax.lean,Mathlib/Analysis/Complex/Liouville.lean,Mathlib/Analysis/InnerProductSpace/Completion.lean,Mathlib/Analysis/Normed/Group/HomCompletion.lean,Mathlib/Analysis/Normed/Module/Completion.lean,Mathlib/Analysis/SpecialFunctions/NonIntegrable.lean,Mathlib/MeasureTheory/Integral/IntegralEqImproper.lean,Mathlib/Topology/Algebra/GroupCompletion.lean,Mathlib/Topology/Algebra/InfiniteSum/GroupCompletion.lean,Mathlib/Topology/Algebra/InfiniteSum/Nonarchimedean.lean,Mathlib/Topology/Algebra/Nonarchimedean/Completion.lean,Mathlib/Topology/Algebra/UniformRing.lean,Mathlib/Topology/Category/UniformSpace.lean,Mathlib/Topology/MetricSpace/Completion.lean,Mathlib/Topology/UniformSpace/Completion.lean	17	4	['eric-wieser', 'github-actions', 'trivial1711']	nobody	325-62275 10 months ago	325-62275 10 months ago	6-66637 6 days
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/)	new-contributor t-topology merge-conflict	285/1	Mathlib.lean,Mathlib/Topology/ContinuousMap/MvPolynomial.lean,Mathlib/Topology/ContinuousMap/StoneWeierstrass.lean	3	1	['github-actions']	nobody	274-59583 8 months ago	274-59583 8 months ago	16-76141 16 days
22660	Ruben-VandeVelde author:Ruben-VandeVelde	chore: follow naming convention around Group.IsNilpotent	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	133/67	Mathlib/GroupTheory/Frattini.lean,Mathlib/GroupTheory/Nilpotent.lean,Mathlib/GroupTheory/SpecificGroups/ZGroup.lean	3	1	['github-actions']	nobody	262-81838 8 months ago	262-81838 8 months ago	10-48025 10 days
22701	ctchou author:ctchou	feat(Combinatorics): the Katona circle method	This file formalizes the Katona circle method. From PlainCombi (LeanCamCombi): https://github.com/YaelDillies/LeanCamCombi/blob/master/LeanCamCombi/PlainCombi/KatonaCircle.lean Co-authored-by: Yaël Dillies	new-contributor t-combinatorics merge-conflict	121/0	Mathlib.lean,Mathlib/Combinatorics/KatonaCircle.lean	2	1	['github-actions']	nobody	242-35352 7 months ago	242-35352 7 months ago	30-8337 30 days
23411	PatrickMassot author:PatrickMassot	chore: remove finiteness from Order.Filter.Lift	Co-authored-by: Anatole Dedecker --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	longest-pole t-topology merge-conflict	48/21	Mathlib/Dynamics/TopologicalEntropy/DynamicalEntourage.lean,Mathlib/Order/Filter/Basic.lean,Mathlib/Order/Filter/Finite.lean,Mathlib/Order/Filter/Lift.lean,Mathlib/Order/Filter/SmallSets.lean,Mathlib/Topology/Algebra/ContinuousMonoidHom.lean,Mathlib/Topology/Basic.lean	7	4	['Vierkantor', 'github-actions', 'kim-em', 'leanprover-community-bot-assistant']	nobody	240-82066 7 months ago	241-15235 7 months ago	10-21608 10 days
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/)	new-contributor t-category-theory merge-conflict	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	239-67985 7 months ago	239-67986 7 months ago	58-20339 58 days
21525	sinhp author:sinhp	feat(CategoryTheory): Locally Cartesian Closed Categories (Prelim)	This PR defines the basic preliminaries for defining locally cartesian closed categories (LCCCs). In particular, using the calculus of mates we define certain natural isomorphisms involving `Over.star` and `Over.pullback` which will be crucial in defining the right adjoint to the pullback functor in the development of LCCCs. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import t-category-theory merge-conflict	338/24	Mathlib/CategoryTheory/Comma/Over/Basic.lean,Mathlib/CategoryTheory/Comma/Over/Pullback.lean,Mathlib/CategoryTheory/Galois/Examples.lean	3	13	['b-mehta', 'github-actions', 'joelriou', 'leanprover-community-bot-assistant', 'sinhp']	nobody	239-67983 7 months ago	239-67985 7 months ago	43-83249 43 days
20567	grunweg author:grunweg	feat(Cache): two small features	- add an informational message to the get command (when run without arguments): when more than 80% of all cache files present were not used in the last command, tell the user about the `clean` command --- - [ ] depends on #20568 (for the first feature) - [ ] TODO: re-design this feature and the clean command: if there are N local copies of mathlib, cache should have a pointer to all of them - to avoid clearing all N-1 from inside the last local copy [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-meta merge-conflict	38/2	Cache/Main.lean	1	11	['Julian', 'arthurpaulino', 'fpvandoorn', 'github-actions', 'grunweg']	nobody	231-41945 7 months ago	231-41945 7 months ago	1-17369 1 day
23859	urkud author:urkud	feat(Topology/../Order/Field): generalize to `Semifield`	.. from a linear ordered field to a linear ordered semifield--- - [ ] depends on: #23857 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology merge-conflict	245/219	Mathlib/Algebra/Order/Group/Pointwise/Interval.lean,Mathlib/Analysis/BoxIntegral/Box/SubboxInduction.lean,Mathlib/Topology/Algebra/Order/Field.lean,Mathlib/Topology/Order/Basic.lean	4	3	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	226-80859 7 months ago	226-80862 7 months ago	0-265 4 minutes
23810	b-reinke author:b-reinke	chore(Order/Interval): generalize succ/pred lemmas to partial orders	Many lemmas in `Mathlib/Order/Interval/Set/SuccPred.lean`and `Mathlib/Order/Interval/Finset/SuccPred.lean` also work for partial orders. They are generalized in this PR by introducing different sections for `PartialOrder` and `LinearOrder` assumptions in the respective files. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-order merge-conflict	231/89	Mathlib/Order/Interval/Finset/SuccPred.lean,Mathlib/Order/Interval/Set/SuccPred.lean	2	2	['github-actions', 'leanprover-community-bot-assistant']	nobody	224-57634 7 months ago	224-57636 7 months ago	16-29623 16 days
24285	madvorak author:madvorak	chore(Algebra/*-{Category,Homology}): remove unnecessary universe variables	Discussions: https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Call.20for.20help.3A.20technical.2F.20organisational.20debt/with/513620128 https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Algebra.20and.20.60Type.60/with/513558902 https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Task.2026.3A.20Replace.20Type.20u.20by.20Type.20wherever.20possible/with/513592993 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	542/916	Mathlib/Algebra/AddTorsor/Basic.lean,Mathlib/Algebra/Algebra/Defs.lean,Mathlib/Algebra/Algebra/Equiv.lean,Mathlib/Algebra/Algebra/Field.lean,Mathlib/Algebra/Algebra/Hom.lean,Mathlib/Algebra/Algebra/Operations.lean,Mathlib/Algebra/Algebra/Spectrum/Basic.lean,Mathlib/Algebra/Algebra/Subalgebra/Lattice.lean,Mathlib/Algebra/Algebra/Subalgebra/Tower.lean,Mathlib/Algebra/Algebra/Tower.lean,Mathlib/Algebra/Central/Basic.lean,Mathlib/Algebra/Central/Defs.lean,Mathlib/Algebra/Central/TensorProduct.lean,Mathlib/Algebra/CharP/Pi.lean,Mathlib/Algebra/CharP/Quotient.lean,Mathlib/Algebra/CharP/Subring.lean,Mathlib/Algebra/DirectSum/Algebra.lean,Mathlib/Algebra/DirectSum/Basic.lean,Mathlib/Algebra/DirectSum/Finsupp.lean,Mathlib/Algebra/DirectSum/Module.lean,Mathlib/Algebra/EuclideanDomain/Basic.lean,Mathlib/Algebra/EuclideanDomain/Defs.lean,Mathlib/Algebra/Field/Basic.lean,Mathlib/Algebra/Field/Defs.lean,Mathlib/Algebra/Field/IsField.lean,Mathlib/Algebra/Field/MinimalAxioms.lean,Mathlib/Algebra/Field/Subfield/Basic.lean,Mathlib/Algebra/Field/Subfield/Defs.lean,Mathlib/Algebra/FreeNonUnitalNonAssocAlgebra.lean,Mathlib/Algebra/Group/Conj.lean,Mathlib/Algebra/Group/Defs.lean,Mathlib/Algebra/Group/Equiv/Finite.lean,Mathlib/Algebra/Group/Ext.lean,Mathlib/Algebra/Group/Hom/End.lean,Mathlib/Algebra/Group/Hom/Instances.lean,Mathlib/Algebra/Group/Invertible/Basic.lean,Mathlib/Algebra/Group/Invertible/Defs.lean,Mathlib/Algebra/Group/Pi/Basic.lean,Mathlib/Algebra/Group/Pi/Lemmas.lean,Mathlib/Algebra/Group/TypeTags/Basic.lean,Mathlib/Algebra/Group/TypeTags/Finite.lean,Mathlib/Algebra/Group/TypeTags/Hom.lean,Mathlib/Algebra/Group/Units/Basic.lean,Mathlib/Algebra/Group/Units/Defs.lean,Mathlib/Algebra/Group/Units/Hom.lean,Mathlib/Algebra/Group/WithOne/Basic.lean,Mathlib/Algebra/Group/WithOne/Defs.lean,Mathlib/Algebra/GroupWithZero/Action/Pi.lean,Mathlib/Algebra/GroupWithZero/Defs.lean,Mathlib/Algebra/GroupWithZero/Invertible.lean,Mathlib/Algebra/GroupWithZero/NeZero.lean,Mathlib/Algebra/Lie/Abelian.lean,Mathlib/Algebra/Lie/Basic.lean,Mathlib/Algebra/Lie/CartanMatrix.lean,Mathlib/Algebra/Lie/CartanSubalgebra.lean,Mathlib/Algebra/Lie/Character.lean,Mathlib/Algebra/Lie/Classical.lean,Mathlib/Algebra/Lie/DirectSum.lean,Mathlib/Algebra/Lie/Free.lean,Mathlib/Algebra/Lie/Ideal.lean,Mathlib/Algebra/Lie/IdealOperations.lean,Mathlib/Algebra/Lie/Matrix.lean,Mathlib/Algebra/Lie/Nilpotent.lean,Mathlib/Algebra/Lie/NonUnitalNonAssocAlgebra.lean,Mathlib/Algebra/Lie/OfAssociative.lean,Mathlib/Algebra/Lie/Quotient.lean,Mathlib/Algebra/Lie/SkewAdjoint.lean,Mathlib/Algebra/Lie/Solvable.lean,Mathlib/Algebra/Lie/Subalgebra.lean,Mathlib/Algebra/Lie/Submodule.lean,Mathlib/Algebra/Lie/TensorProduct.lean,Mathlib/Algebra/Lie/UniversalEnveloping.lean,Mathlib/Algebra/Module/Basic.lean,Mathlib/Algebra/Module/CharacterModule.lean,Mathlib/Algebra/Module/DedekindDomain.lean,Mathlib/Algebra/Module/Defs.lean,Mathlib/Algebra/Module/End.lean,Mathlib/Algebra/Module/Equiv/Opposite.lean,Mathlib/Algebra/Module/Lattice.lean,Mathlib/Algebra/Module/LinearMap/Basic.lean,Mathlib/Algebra/Module/LinearMap/Defs.lean,Mathlib/Algebra/Module/LinearMap/End.lean,Mathlib/Algebra/Module/LocalizedModule/Basic.lean,Mathlib/Algebra/Module/MinimalAxioms.lean,Mathlib/Algebra/Module/NatInt.lean,Mathlib/Algebra/Module/Opposite.lean,Mathlib/Algebra/Module/Pi.lean,Mathlib/Algebra/Module/Presentation/Differentials.lean,Mathlib/Algebra/Module/Presentation/Tensor.lean,Mathlib/Algebra/Module/Rat.lean,Mathlib/Algebra/Module/RingHom.lean,Mathlib/Algebra/Module/Submodule/Basic.lean,Mathlib/Algebra/Module/Torsion.lean,Mathlib/Algebra/MonoidAlgebra/Basic.lean,Mathlib/Algebra/MonoidAlgebra/Defs.lean,Mathlib/Algebra/MonoidAlgebra/Support.lean,Mathlib/Algebra/MvPolynomial/Basic.lean,Mathlib/Algebra/MvPolynomial/CommRing.lean,Mathlib/Algebra/MvPolynomial/Degrees.lean,Mathlib/Algebra/MvPolynomial/Equiv.lean	182	22	['erdOne', 'github-actions', 'leanprover-bot', 'leanprover-community-bot-assistant', 'madvorak', 'mattrobball']	nobody	224-46331 7 months ago	224-46332 7 months ago	2-12022 2 days
24354	grunweg author:grunweg	chore(HasFiniteIntegral): rename three lemmas	Discovered in #24343. --- - [ ] depends on: #24343 (to avoid merge conflicts) [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-measure-probability merge-conflict	108/30	Mathlib/MeasureTheory/Function/L1Space/HasFiniteIntegral.lean	1	3	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	219-50735 7 months ago	219-50736 7 months ago	0-4604 1 hour
23546	JovanGerb author:JovanGerb	feat(LinearAlgebra/AffineSpace/AffineSubspace): rename `AffineSubspace.mk'` to `Submodule.shift`	In addition to renaming, I've refactored the code a bit: - `mem_mk'_iff_vsub_mem` was obsolete since it was the same as `mem_mk'`, so I removed it (this is due to a change in the definition I made recently) - I added a nonempty instance for `shift` - I added a simp lemma that `shift` isn't equal to `⊥` (the empty affine subspace). I need this for the next point. - Edit: I'll leave this for a later PR. ~I proved a simp lemma that a `shift` is parallel to a `shift` if and only if the linear subspaces are the same.~ - I renamed `mk'_eq` to `shift_direction_eq_self `. - I renamed `eq_or_eq_secondInter_of_mem_mk'_span_singleton_iff_mem` to `eq_or_eq_secondInter_iff_mem_of_mem_shift_span_singleton`. I think it is better to put the `of_mem_mk'_span_singleton` at the end of the name. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-euclidean-geometry merge-conflict	128/99	Mathlib/Algebra/Module/ZLattice/Basic.lean,Mathlib/Geometry/Euclidean/Basic.lean,Mathlib/Geometry/Euclidean/MongePoint.lean,Mathlib/Geometry/Euclidean/PerpBisector.lean,Mathlib/Geometry/Euclidean/Sphere/SecondInter.lean,Mathlib/Geometry/Euclidean/Sphere/Tangent.lean,Mathlib/LinearAlgebra/AffineSpace/AffineSubspace/Defs.lean	7	4	['JovanGerb', 'github-actions', 'leanprover-community-bot-assistant']	nobody	214-62863 7 months ago	214-62864 7 months ago	26-25420 26 days
22837	joneugster author:joneugster	feat(Data/Set/Basic): add subset_iff and not_mem_subset_iff	Add `Set.subset_iff` for consistent API with `Finset.subset_iff`. Add `Set.not_mem_subset_iff` and `Finset.not_mem_subset_iff`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-set-theory t-data merge-conflict	9/0	Mathlib/Data/Finset/Defs.lean,Mathlib/Data/Set/Basic.lean	2	4	['Ruben-VandeVelde', 'github-actions', 'joneugster', 'leanprover-community-bot-assistant']	nobody	193-65863 6 months ago	193-65865 6 months ago	30-35190 30 days
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). --- - [ ] depends on: #24570 - [ ] 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/)	t-linter merge-conflict	58/19	Mathlib/Tactic/Linter/TextBased.lean,scripts/lint-style.lean	2	19	['Vierkantor', 'adomani', 'github-actions', 'grunweg', 'joneugster', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	joneugster assignee:joneugster	192-71351 6 months ago	192-71354 6 months ago	43-17409 43 days
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/)	large-import new-contributor t-topology merge-conflict	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	191-53081 6 months ago	191-53083 6 months ago	35-30364 35 days
21182	joneugster author:joneugster	fix(Util/CountHeartbeats): move elaboration in #count_heartbeats inside a namespace	Currently the `#count_heartbeat` linter reported the heartbeats until it concluded `error: [declaration] has already been declared` instead of re-elaborating the declaration. --- [Zulip report](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/count_heartbeats.20for.20all.20declarations.20in.20a.20file.3F/near/496303652) [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-meta merge-conflict	72/5	Mathlib/Util/CountHeartbeats.lean,MathlibTest/CountHeartbeats.lean	2	17	['adomani', 'github-actions', 'joneugster', 'leanprover-community-bot-assistant', 'mathlib-bors']	adomani assignee:adomani	184-81829 6 months ago	184-81830 6 months ago	64-19141 64 days
25340	dupuisf author:dupuisf	chore(Analysis/Convex): move files pertaining to convex/concave functions to their own folder	This PR creates a new folder under `Analysis/Convex` called `Analysis/Convex/Function`, which includes files that are mostly or entirely about convex/concave functions (as opposed to convex sets). --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-convex-geometry merge-conflict	4264/4155	Mathlib.lean,Mathlib/Analysis/Convex/Continuous.lean,Mathlib/Analysis/Convex/Deriv.lean,Mathlib/Analysis/Convex/Exposed.lean,Mathlib/Analysis/Convex/Extrema.lean,Mathlib/Analysis/Convex/Function.lean,Mathlib/Analysis/Convex/Function/Basic.lean,Mathlib/Analysis/Convex/Function/Continuous.lean,Mathlib/Analysis/Convex/Function/Deriv.lean,Mathlib/Analysis/Convex/Function/Extrema.lean,Mathlib/Analysis/Convex/Function/Integral.lean,Mathlib/Analysis/Convex/Function/Jensen.lean,Mathlib/Analysis/Convex/Function/Mul.lean,Mathlib/Analysis/Convex/Function/Piecewise.lean,Mathlib/Analysis/Convex/Function/Quasiconvex.lean,Mathlib/Analysis/Convex/Function/Slope.lean,Mathlib/Analysis/Convex/Function/Strong.lean,Mathlib/Analysis/Convex/Integral.lean,Mathlib/Analysis/Convex/Jensen.lean,Mathlib/Analysis/Convex/Mul.lean,Mathlib/Analysis/Convex/Piecewise.lean,Mathlib/Analysis/Convex/Quasiconvex.lean,Mathlib/Analysis/Convex/Slope.lean,Mathlib/Analysis/Convex/SpecificFunctions/Basic.lean,Mathlib/Analysis/Convex/SpecificFunctions/Deriv.lean,Mathlib/Analysis/Convex/Strong.lean,Mathlib/Analysis/MeanInequalities.lean,Mathlib/Analysis/MeanInequalitiesPow.lean,Mathlib/Analysis/Normed/Module/Convex.lean,Mathlib/Analysis/Seminorm.lean,Mathlib/Analysis/SpecialFunctions/Log/NegMulLog.lean,Mathlib/Analysis/SpecialFunctions/Pochhammer.lean,Mathlib/MeasureTheory/Measure/Decomposition/IntegralRNDeriv.lean,Mathlib/NumberTheory/Harmonic/GammaDeriv.lean	34	2	['github-actions', 'leanprover-community-bot-assistant']	nobody	180-75908 5 months ago	180-75910 5 months ago	6-40169 6 days
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/)	t-algebra merge-conflict 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	153-14597 5 months ago	153-14597 5 months ago	43-42841 43 days
25071	erdOne author:erdOne	feat(EllipticCurve): basic API for singular cubics	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebraic-geometry merge-conflict	320/0	Mathlib.lean,Mathlib/AlgebraicGeometry/EllipticCurve/Singular/Basic.lean,Mathlib/AlgebraicGeometry/EllipticCurve/VariableChange.lean	3	35	['Multramate', 'acmepjz', 'erdOne', 'github-actions', 'leanprover-community-bot-assistant']	nobody	153-14351 5 months ago	153-14352 5 months ago	45-4961 45 days
25283	Brian-Nugent author:Brian-Nugent	feat: regular local rings	Adds regular local rings and proves they are integral domains. --- - [ ] depends on: #25280 - [ ] depends on: #25282 [![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$	871/0	.vscode/settings.json,Mathlib.lean,Mathlib/RingTheory/EmbeddingDimension.lean,Mathlib/RingTheory/LocalRingDimension.lean,Mathlib/RingTheory/RegularLocalRing.lean	5	6	['Brian-Nugent', 'github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'yuanyi-350']	nobody	153-14344 5 months ago	153-14344 5 months ago	11-84822 11 days
25573	JovanGerb author:JovanGerb	feat: define `∃ x > y, ...` notation to mean `∃ x, y < x ∧ ...`	This PR changes the elaboration of the binders `∃ x > y,` and `∀ x > y,` to use `<` instead of `>`, because we want to avoid working with `>` as much as possible (and similarly for `≥` vs `≤` ). The advantage is that we don't need to worry about rewriting with lemmas like `gt_iff_lt`. The disadvantage is that people might find this confusing. [#mathlib4 > naming convention for ≤ and < @ 💬](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/naming.20convention.20for.20.E2.89.A4.20and.20.3C/near/522910464) The main changes are in `Mathlib.Init`, `Mathlib.Util.Delaborators` and `MathlibTest.delaborators`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-meta merge-conflict	59/52	Counterexamples/DiscreteTopologyNonDiscreteUniformity.lean,Mathlib/Algebra/Order/Monoid/Canonical/Defs.lean,Mathlib/Analysis/Analytic/Basic.lean,Mathlib/Analysis/BoxIntegral/Integrability.lean,Mathlib/Analysis/Calculus/UniformLimitsDeriv.lean,Mathlib/Analysis/Complex/Liouville.lean,Mathlib/Analysis/Complex/OpenMapping.lean,Mathlib/Analysis/Fourier/PoissonSummation.lean,Mathlib/Analysis/MellinTransform.lean,Mathlib/Analysis/Normed/Operator/Banach.lean,Mathlib/Dynamics/Ergodic/Conservative.lean,Mathlib/Dynamics/PeriodicPts/Defs.lean,Mathlib/Geometry/Manifold/IntegralCurve/ExistUnique.lean,Mathlib/Init.lean,Mathlib/MeasureTheory/Covering/LiminfLimsup.lean,Mathlib/MeasureTheory/Function/ConvergenceInMeasure.lean,Mathlib/MeasureTheory/Function/Egorov.lean,Mathlib/MeasureTheory/Function/StronglyMeasurable/Basic.lean,Mathlib/MeasureTheory/Integral/DivergenceTheorem.lean,Mathlib/MeasureTheory/Integral/Layercake.lean,Mathlib/NumberTheory/LSeries/SumCoeff.lean,Mathlib/Order/Filter/AtTopBot/Finite.lean,Mathlib/RingTheory/RootsOfUnity/PrimitiveRoots.lean,Mathlib/RingTheory/Valuation/Basic.lean,Mathlib/Topology/CWComplex/Classical/Finite.lean,Mathlib/Topology/ContinuousMap/Ideals.lean,Mathlib/Topology/EMetricSpace/Defs.lean,Mathlib/Topology/EMetricSpace/Paracompact.lean,Mathlib/Topology/LocallyFinite.lean,Mathlib/Topology/MetricSpace/Ultra/Basic.lean,Mathlib/Util/Delaborators.lean,MathlibTest/delaborators.lean	32	2	['github-actions', 'leanprover-community-bot-assistant']	nobody	153-14332 5 months ago	153-14333 5 months ago	26-17604 26 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	t-algebraic-geometry merge-conflict	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	153-14039 5 months ago	153-14039 5 months ago	18-21880 18 days
24405	mcdoll author:mcdoll	refactor(Topology/Algebra/Module/WeakDual): Clean up	- Move `Dual` and `dualPairing` lower in the import-hierachy - deduplicate `dualPairing` - Make `WeakDual` and `WeakSpace` reducible --- New version of #11500 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import t-topology merge-conflict	146/162	Mathlib.lean,Mathlib/Analysis/Fourier/RiemannLebesgueLemma.lean,Mathlib/Analysis/InnerProductSpace/Adjoint.lean,Mathlib/Analysis/InnerProductSpace/Dual.lean,Mathlib/Analysis/LocallyConvex/WeakSpace.lean,Mathlib/Analysis/Normed/Module/Dual.lean,Mathlib/Analysis/Normed/Module/WeakDual.lean,Mathlib/Analysis/VonNeumannAlgebra/Basic.lean,Mathlib/MeasureTheory/Function/AEEqOfIntegral.lean,Mathlib/MeasureTheory/Measure/FiniteMeasure.lean,Mathlib/Topology/Algebra/Module/Dual.lean,Mathlib/Topology/Algebra/Module/WeakDual.lean,docs/overview.yaml,docs/undergrad.yaml	14	2	['github-actions', 'leanprover-community-bot-assistant']	nobody	151-65868 4 months ago	151-65869 4 months ago	69-52361 69 days
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/)	t-topology merge-conflict	18/0	Mathlib/Topology/StoneCech.lean	1	2	['github-actions', 'leanprover-community-bot-assistant']	nobody	149-81817 4 months ago	149-81817 4 months ago	20-8582 20 days
26608	vihdzp author:vihdzp	feat(SetTheory/Cardinal/Aleph): `o.card ≤ ℵ_ o` and variants	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-set-theory merge-conflict	24/0	Mathlib/SetTheory/Cardinal/Aleph.lean	1	3	['github-actions', 'kckennylau', 'leanprover-community-bot-assistant']	nobody	132-45092 4 months ago	132-45093 4 months ago	23-63406 23 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/)	t-algebraic-topology infinity-cosmos t-meta merge-conflict	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	23	['eric-wieser', 'gio256', 'github-actions', 'kim-em', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	eric-wieser assignee:eric-wieser	126-72694 4 months ago	126-72694 4 months ago	88-84229 88 days
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/)	new-contributor t-meta merge-conflict	17/5	Mathlib/Tactic/ComputeDegree.lean,MathlibTest/ComputeDegree.lean	2	3	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	122-79079 4 months ago	122-79079 4 months ago	38-26044 38 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/)	CI merge-conflict	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	121-30032 3 months ago	121-30032 3 months ago	46-52210 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/)	t-ring-theory merge-conflict	27/0	Mathlib/RingTheory/Valuation/Basic.lean	1	13	['JovanGerb', 'github-actions', 'kckennylau', 'mathlib4-merge-conflict-bot', 'pechersky', 'wwylele']	nobody	115-62535 3 months ago	115-62536 3 months ago	17-52359 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/)	t-ring-theory large-import merge-conflict	73/0	Mathlib/RingTheory/Valuation/Basic.lean	1	4	['JovanGerb', 'github-actions', 'kckennylau', 'mathlib4-merge-conflict-bot']	nobody	115-62164 3 months ago	115-62165 3 months ago	6-6455 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/)	t-meta merge-conflict	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	113-76788 3 months ago	113-76789 3 months ago	32-70098 32 days
25483	VTrelat author:VTrelat	chore(Data/Set/Prod, SetTheory/ZFC/Basic): add theorem prod_subset_of_prod and extend ZFC model	Required by @eric-wieser in #24281 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data new-contributor merge-conflict	103/0	Mathlib/Data/Set/Prod.lean,Mathlib/SetTheory/ZFC/Basic.lean	2	10	['Ruben-VandeVelde', 'VTrelat', 'github-actions', 'leanprover-community-bot-assistant']	nobody	113-66431 3 months ago	153-14338 5 months ago	29-56208 29 days
25401	digama0 author:digama0	feat(Util): SuppressSorry option	See also leanprover/lean4#8611 and [#lean4 > Silent sorry @ 💬](https://leanprover.zulipchat.com/#narrow/channel/270676-lean4/topic/Silent.20sorry/near/503537964). This is a stop-gap solution while leanprover/lean4#8611 is underway, but it works about as well as any other built in option. Hooking declaration elaborators turns out to be a very powerful technique. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-meta merge-conflict	342/0	Mathlib.lean,Mathlib/Util/CommandElabHook.lean,Mathlib/Util/SuppressSorry.lean,MathlibTest/suppressSorry.lean	4	15	['digama0', 'eric-wieser', 'github-actions', 'mathlib4-merge-conflict-bot']	alexjbest assignee:alexjbest	113-31584 3 months ago	113-31584 3 months ago	71-28549 71 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	107-35064 3 months ago	107-35065 3 months ago	0-83357 23 hours
28532	alreadydone author:alreadydone	chore(Algebra/Ring/Defs): add two classes and extend more	Add the missing `NonAssocComm(Semi)ring` and modify existing classes to `extends` more to remove some manual instances. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	89/70	Mathlib/Algebra/Colimit/DirectLimit.lean,Mathlib/Algebra/Ring/Defs.lean,Mathlib/Analysis/Normed/Unbundled/SpectralNorm.lean,Mathlib/LinearAlgebra/CliffordAlgebra/Basic.lean,Mathlib/NumberTheory/SelbergSieve.lean,Mathlib/RingTheory/Localization/Integral.lean,Mathlib/RingTheory/PowerSeries/GaussNorm.lean,Mathlib/RingTheory/Valuation/Discrete/Basic.lean,Mathlib/Tactic/Ring/Basic.lean,MathlibTest/TCSynth.lean	10	17	['alreadydone', 'eric-wieser', 'github-actions', 'leanprover-bot', 'mathlib4-merge-conflict-bot']	nobody	106-54927 3 months ago	106-54928 3 months ago	2-77063 2 days
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	105-64190 3 months ago	105-64191 3 months ago	2-48353 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/)	t-data new-contributor merge-conflict	24/26	Mathlib/Data/TypeVec.lean	1	7	['Equilibris', 'alexkeizer', 'github-actions', 'mathlib4-merge-conflict-bot']	nobody	104-31506 3 months ago	104-31507 3 months ago	13-49738 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/)	new-contributor merge-conflict	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	104-10826 3 months ago	126-73148 4 months ago	7-54661 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/)	t-ring-theory merge-conflict	140/23	Mathlib/RingTheory/Valuation/ValuativeRel.lean,Mathlib/Topology/Algebra/Valued/ValuativeRel.lean	2	3	['github-actions', 'grunweg', 'mathlib4-merge-conflict-bot']	nobody	104-10780 3 months ago	104-10780 3 months ago	7-4998 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/)	new-contributor merge-conflict	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	103-59058 3 months ago	126-73149 4 months ago	7-62439 7 days
25889	plp127 author:plp127	fix(Tactic/Widget/Conv): fix various issues	Fixes various issues with the `conv?` widget. Closes #25162. ([Zulip thread](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/bug.20in.20.60conv.3F.60)) Specifically, fixes issues with `conv?` where - when converting a `SubExpr.Pos` to conv directions, it always uses the goal expression as reference, even when working on a hypothesis, this often leads to bad results and makes it unusable on hypotheses - it refuses to go all the way in to a function (for example in `Nat.succ 0`, you can't access `Nat.succ`) - it refuses to enter binders where the name of the bound variable contains the character `0` (try it on `∀ (x0 : Nat), x0 = x0`) - it panics if it can't find a binder name instead of just coming up with one itself, this also means usually you can't enter either side of a non-dependent arrow since those usually don't have binder names (try it on `False → False`) - you can't enter the type of a binder, you end up going into the body instead (try it on `fun (x : False) => (x.elim : False → Nat) x.elim`) - you can't partially enter a function, you end up going to the top argument after instead (for example, in the expression `id (id id) 0`, when you click on `id (id id)`, you end up going to `id id`) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-meta merge-conflict	419/84	Mathlib/Tactic/Widget/Conv.lean,MathlibTest/conv?.lean	2	5	['bryangingechen', 'github-actions', 'mathlib4-merge-conflict-bot', 'plp127']	bryangingechen and kmill assignee:kmill assignee:bryangingechen	102-47351 3 months ago	102-47352 3 months ago	70-58775 70 days
27785	staroperator author:staroperator	chore(Algebra/Group/Submonoid): golf `Nat.addSubmonoidClosure_one` using `simp`	This should improve the proof readability. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import t-algebra merge-conflict label:t-algebra$	8/15	Mathlib/Algebra/Group/Submonoid/Membership.lean,Mathlib/Algebra/Group/Submonoid/Operations.lean,Mathlib/Algebra/Order/Star/Basic.lean	3	9	['github-actions', 'joneugster', 'leanprover-bot', 'mathlib4-merge-conflict-bot', 'staroperator']	joneugster assignee:joneugster	99-16121 3 months ago	99-16122 3 months ago	26-34065 26 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/)	t-meta merge-conflict	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	99-15992 3 months ago	99-15993 3 months ago	16-54453 16 days
27566	wwylele author:wwylele	feat(Data/Real): Archimedean.embedReal is a ring hom when M is an ordered ring	Also shows that this ends up the same as `LinearOrderedField.inducedOrderRingHom` for fields --- This is a spin-off from #27268 ~~because I got bored~~ . This is not in a high priority as I don't need it for anything yet, but the last lemma shows that `embedReal` is a generalization of `LinearOrderedField.inducedOrderRingHom` (which is only stated for field, and I didn't find when I was making the group embedding). Perhaps we should refactor `Mathlib/Algebra/Order/CompleteField.lean` with the definition here. Indeed, if we replace every `ℝ` with `(R : Type*)[ConditionallyCompleteLinearOrderedField R]` in `Data/Real/Embedding.lean`, the proof still works. What do you think? [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import t-data merge-conflict	220/3	Mathlib/Data/Real/Embedding.lean	1	2	['github-actions', 'mathlib4-merge-conflict-bot']	nobody	90-9111 2 months ago	90-9112 2 months ago	40-32085 40 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/)	t-category-theory merge-conflict	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	87-62338 2 months ago	87-62339 2 months ago	0-1812 30 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/)	t-category-theory merge-conflict	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	87-57377 2 months ago	87-58165 2 months ago	0-1002 16 minutes
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/)	t-category-theory merge-conflict	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	86-71228 2 months ago	87-58162 2 months ago	0-1 1 second
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 ---	new-contributor t-logic merge-conflict	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	86-65089 2 months ago	86-65090 2 months ago	21-3001 21 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/)	t-data merge-conflict	459/212	Mathlib/Data/Ordmap/Ordnode.lean	1	4	['eric-wieser', 'github-actions', 'grunweg', 'mathlib4-merge-conflict-bot']	nobody	83-15722 2 months ago	83-15723 2 months ago	39-69478 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	t-topology merge-conflict	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	80-77333 2 months ago	80-77334 2 months ago	87-79752 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/)	t-group-theory merge-conflict	61/68	Mathlib/GroupTheory/Perm/Fin.lean	1	10	['JovanGerb', 'eric-wieser', 'github-actions', 'mathlib4-merge-conflict-bot', 'plp127', 'tb65536']	nobody	72-2530 2 months ago	72-2531 2 months ago	20-39203 20 days
21950	erdOne author:erdOne	feat(NumberTheory/Padics): the completion of `ℚ` at a finite place is `ℚ_[p]`	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-number-theory merge-conflict	253/1	Mathlib.lean,Mathlib/Algebra/GroupWithZero/WithZero.lean,Mathlib/NumberTheory/Padics/HeightOneSpectrum.lean,Mathlib/NumberTheory/Padics/PadicNumbers.lean,Mathlib/Topology/Algebra/Valued/WithVal.lean,Mathlib/Topology/Algebra/WithZeroMulInt.lean,Mathlib/Topology/Algebra/WithZeroTopology.lean	7	33	['Ruben-VandeVelde', 'erdOne', 'faenuccio', 'github-actions', 'leanprover-community-bot-assistant', 'pechersky', 'smmercuri', 'xroblot']	nobody	69-64040 2 months ago	150-63977 4 months ago	79-1228 79 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/)	t-category-theory merge-conflict	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	66-54122 2 months ago	66-54123 2 months ago	0-5521 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/)	t-algebraic-topology t-category-theory merge-conflict	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	65-73524 2 months ago	65-73526 2 months ago	0-1708 28 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/)	large-import t-category-theory merge-conflict	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	64-76749 2 months ago	64-79721 2 months ago	0-625 10 minutes
25042	alreadydone author:alreadydone	feat(Topology): restriction/extension of Trivialization and composition with Homeomorph	--- - [x] depends on: #25041 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology merge-conflict	148/2	Mathlib/Topology/FiberBundle/Trivialization.lean,Mathlib/Topology/Maps/Basic.lean	2	4	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	ADedecker assignee:ADedecker	63-79193 2 months ago	63-79194 2 months ago	134-68375 134 days
23621	astrainfinita author:astrainfinita	chore: deprecate `LinearOrderedComm{Monoid, Group}WithZero`	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) - [x] depends on: #20676	t-order t-algebra merge-conflict label:t-algebra$	261/205	Archive/Imo/Imo1998Q2.lean,Counterexamples/LinearOrderWithPosMulPosEqZero.lean,Mathlib/Algebra/Order/Field/Canonical.lean,Mathlib/Algebra/Order/Field/Rat.lean,Mathlib/Algebra/Order/Floor/Ring.lean,Mathlib/Algebra/Order/GroupWithZero/Canonical.lean,Mathlib/Algebra/Order/GroupWithZero/Finset.lean,Mathlib/Algebra/Order/Hom/Monoid.lean,Mathlib/Algebra/Order/Nonneg/Field.lean,Mathlib/Algebra/Order/Nonneg/Ring.lean,Mathlib/Algebra/Order/Ring/Nat.lean,Mathlib/Combinatorics/Additive/PluenneckeRuzsa.lean,Mathlib/Combinatorics/SimpleGraph/Triangle/Basic.lean,Mathlib/Data/ENNReal/Basic.lean,Mathlib/Data/NNRat/Lemmas.lean,Mathlib/Data/NNReal/Defs.lean,Mathlib/Data/Rat/Cast/Order.lean,Mathlib/FieldTheory/IntermediateField/Adjoin/Defs.lean,Mathlib/FieldTheory/RatFunc/AsPolynomial.lean,Mathlib/GroupTheory/ArchimedeanDensely.lean,Mathlib/NumberTheory/EllipticDivisibilitySequence.lean,Mathlib/NumberTheory/FunctionField.lean,Mathlib/NumberTheory/Ostrowski.lean,Mathlib/RingTheory/Valuation/Archimedean.lean,Mathlib/RingTheory/Valuation/Basic.lean,Mathlib/RingTheory/Valuation/ExtendToLocalization.lean,Mathlib/RingTheory/Valuation/Integers.lean,Mathlib/RingTheory/Valuation/Integral.lean,Mathlib/RingTheory/Valuation/Minpoly.lean,Mathlib/RingTheory/Valuation/Quotient.lean,Mathlib/RingTheory/Valuation/RankOne.lean,Mathlib/RingTheory/Valuation/ValExtension.lean,Mathlib/RingTheory/Valuation/ValuationRing.lean,Mathlib/RingTheory/Valuation/ValuationSubring.lean,Mathlib/SetTheory/Cardinal/Order.lean,Mathlib/Topology/Algebra/Valued/LocallyCompact.lean,Mathlib/Topology/Algebra/Valued/NormedValued.lean,Mathlib/Topology/Algebra/Valued/ValuationTopology.lean,Mathlib/Topology/Algebra/Valued/ValuedField.lean,Mathlib/Topology/Algebra/Valued/WithVal.lean,Mathlib/Topology/Algebra/WithZeroTopology.lean,Mathlib/Topology/UnitInterval.lean,MathlibTest/instance_diamonds.lean,scripts/noshake.json	44	n/a	['YaelDillies', 'astrainfinita', 'github-actions', 'grunweg', 'leanprover-bot', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	kbuzzard assignee:kbuzzard	61-58464 2 months ago	unknown	unknown
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	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	57-80393 1 month ago	57-80394 1 month ago	25-78230 25 days
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/)	t-ring-theory merge-conflict	172/0	Counterexamples.lean,Counterexamples/DiscreteTopologyWithNontrivialValuation.lean	2	n/a	['github-actions', 'grunweg', 'kckennylau', 'mathlib4-merge-conflict-bot', 'pechersky']	nobody	53-60595 1 month 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/)	t-analysis merge-conflict	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	51-17031 1 month ago	51-17032 1 month ago	0-14664 4 hours
25978	Bergschaf author:Bergschaf	feat(Order/Sublocale): Open Sublocales	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) - [x] depends on: #25089	t-order merge-conflict	377/8	Mathlib.lean,Mathlib/Order/Hom/Lattice.lean,Mathlib/Order/Nucleus.lean,Mathlib/Order/Sublocale.lean,Mathlib/Order/Synonym.lean,docs/references.bib	6	3	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	42-49451 1 month ago	115-7327 3 months ago	0-1908 31 minutes
30690	grunweg author:grunweg	style(Order): fix whitespace	Extracted from #30658. Found by extending the commandStart linter to proof bodies. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-order merge-conflict	69/69	Mathlib/Order/Basic.lean,Mathlib/Order/Bounds/Image.lean,Mathlib/Order/Defs/PartialOrder.lean,Mathlib/Order/Filter/Cocardinal.lean,Mathlib/Order/Heyting/Basic.lean,Mathlib/Order/KonigLemma.lean,Mathlib/Order/Max.lean,Mathlib/Order/Minimal.lean,Mathlib/Order/Monotone/Basic.lean,Mathlib/Order/PiLex.lean,Mathlib/Order/RelClasses.lean,Mathlib/Order/SetIsMax.lean,Mathlib/Order/SetNotation.lean,Mathlib/Order/WithBot.lean	14	4	['JovanGerb', 'github-actions', 'grunweg', 'mathlib4-merge-conflict-bot']	Vierkantor assignee:Vierkantor	37-74630 1 month ago	37-74631 1 month ago	8-67789 8 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/)	t-algebra merge-conflict 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	30-37193 1 month ago	30-37194 1 month ago	80-71575 80 days
29877	Komyyy author:Komyyy	feat: inner product of the gradient	Also, this PR enables the `conj` notation in the file. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-analysis merge-conflict	37/10	Mathlib/Analysis/Calculus/Gradient/Basic.lean	1	2	['github-actions', 'mathlib4-merge-conflict-bot']	hrmacbeth assignee:hrmacbeth	28-65852 28 days ago	28-65854 28 days ago	45-5432 45 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	t-algebra t-analysis t-number-theory merge-conflict 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	22-65797 22 days ago	22-65797 22 days ago	127-58875 127 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.	t-data merge-conflict	35/0	Mathlib/Data/List/Scan.lean	1	11	['ShreckYe', 'github-actions', 'mathlib4-merge-conflict-bot', 'themathqueen', 'vlad902']	pechersky assignee:pechersky	22-22028 22 days ago	25-19759 25 days ago	74-62841 74 days
27936	alreadydone author:alreadydone	feat(Algebra): additivize Dvd and Prime	`Prime` can't be directly additivized, so we introduce `Preprime`, which drops the `≠ 0` condition, and additivize it to `AddPrime`. To show that `Preprime` is a reasonable definition, we show its connection to `Irreducible` under `IsPrimal` and `IsRegular` conditions. We also show that an element in a product monoid is preprime iff one component is a unit and the other is preprime, and the same with `Preprime` replaced by `Irreducible`. Also additivize `IsPrimal`, `IsRelPrime` and `DecompositionMonoid`. The motivation is that the primality of `single g 1` in `AddMonoidAlgebra k G` is connected to the primality of `g` in `G`. --- I've checked [all 29 files](https://github.com/search?q=repo%3Aleanprover-community%2Fmathlib4%20%E2%88%A3%20to_additive&type=code) containing the `∣` symbol and the `to_additive` attribute and fixed the wrongly translated (`dvd` to `addDvd`) names. TODO: connect (Add)Dvd to [ExistsMul/AddOfLE](https://leanprover-community.github.io/mathlib4_docs/Mathlib/Algebra/Order/Monoid/Unbundled/ExistsOfLE.html#ExistsMulOfLE) [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	400/191	Mathlib.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/List/Lemmas.lean,Mathlib/Algebra/BigOperators/Group/Multiset/Basic.lean,Mathlib/Algebra/Divisibility/Basic.lean,Mathlib/Algebra/Divisibility/Finite.lean,Mathlib/Algebra/Divisibility/Hom.lean,Mathlib/Algebra/Divisibility/Prod.lean,Mathlib/Algebra/Divisibility/Units.lean,Mathlib/Algebra/Group/Action/Pointwise/Finset.lean,Mathlib/Algebra/Group/Prod.lean,Mathlib/Algebra/GroupWithZero/Associated.lean,Mathlib/Algebra/Notation/Defs.lean,Mathlib/Algebra/Prime/Defs.lean,Mathlib/Algebra/Prime/Lemmas.lean,Mathlib/Algebra/Prime/Prod.lean,Mathlib/Data/Nat/Prime/Defs.lean,Mathlib/Dynamics/PeriodicPts/Defs.lean,Mathlib/GroupTheory/Coset/Card.lean,Mathlib/GroupTheory/Exponent.lean,Mathlib/GroupTheory/GroupAction/Blocks.lean,Mathlib/GroupTheory/GroupAction/Period.lean,Mathlib/GroupTheory/Index.lean,Mathlib/GroupTheory/OrderOfElement.lean,Mathlib/GroupTheory/Perm/Cycle/Type.lean,Mathlib/GroupTheory/Schreier.lean,Mathlib/GroupTheory/SpecificGroups/Cyclic.lean,Mathlib/Tactic/ToAdditive/GuessName.lean	30	13	['JovanGerb', 'adomani', 'alreadydone', 'bryangingechen', 'github-actions', 'mathlib4-merge-conflict-bot']	bryangingechen assignee:bryangingechen	22-19751 22 days ago	22-19752 22 days ago	98-49698 98 days
26484	peabrainiac author:peabrainiac	feat(Geometry/Diffeology): basics of diffeological spaces	Introduces diffeological spaces, smooth maps between them, the D-topology and the standard diffeology on finite-dimensional normed spaces. --- This PR continues the work from #21969.	t-differential-geometry merge-conflict	471/0	Mathlib.lean,Mathlib/Geometry/Diffeology/Basic.lean,docs/references.bib	3	11	['JovanGerb', 'github-actions', 'grunweg', 'lecopivo', 'mathlib4-merge-conflict-bot', 'peabrainiac']	grunweg assignee:grunweg	21-78331 21 days ago	21-78332 21 days ago	138-31722 138 days
30962	WangYiran01 author:WangYiran01	feat(Combinatorics/Enumerative): add lattice path lemmas and counts	This PR adds definitions and theorems about monotone lattice paths: - Defines `pathCount`, `pathCountFrom`, `SubdiagProp`, and related structures. - Proves closed forms such as `pathCount_eq_closed`. - Adds Dyck/ballot subdiagonal property (`SubdiagProp`). All code builds successfully with `lake build`.	new-contributor t-combinatorics merge-conflict	64/0	Mathlib.lean,Mathlib/Combinatorics/Enumerative/RecLatticePath.lean	2	2	['github-actions', 'mathlib4-merge-conflict-bot']	awainverse assignee:awainverse	19-33588 19 days ago	19-33588 19 days ago	19-55009 19 days
28013	astrainfinita author:astrainfinita	feat: Lindemann-Weierstrass Theorem	This PR continues the work from #6718. -------- - [x] depends on: #18693 - [ ] depends on: #29121	t-algebra t-analysis merge-conflict label:t-algebra$	1141/54	Mathlib.lean,Mathlib/Algebra/MonoidAlgebra/Basic.lean,Mathlib/Algebra/NoZeroSMulDivisors/Basic.lean,Mathlib/Algebra/Polynomial/Splits.lean,Mathlib/Data/Finsupp/Defs.lean,Mathlib/NumberTheory/Transcendental/Lindemann/AlgebraicPart.lean,Mathlib/NumberTheory/Transcendental/Lindemann/AnalyticalPart.lean,Mathlib/NumberTheory/Transcendental/Lindemann/Basic.lean,Mathlib/RingTheory/MvPolynomial/Symmetric/Eval.lean,docs/100.yaml,docs/1000.yaml	11	n/a	['astrainfinita', 'github-actions', 'j-loreaux', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	18-38064 18 days ago	unknown	unknown
26240	grunweg author:grunweg	perf(CommandLinterLinter): use Substring more	Probably, these changes make little difference, but let's find out. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-linter RFC merge-conflict	14/15	Mathlib/Tactic/Linter/CommandStart.lean	1	6	['github-actions', 'leanprover-bot', 'leanprover-community-mathlib4-bot', 'mathlib4-merge-conflict-bot']	joneugster assignee:joneugster	16-73074 16 days ago	16-73075 16 days ago	150-52942 150 days
29909	Vierkantor author:Vierkantor	feat(CI): add build output to CI workflows	This PR uses the Zulip build report script (originally developed for the nightly-regression-report workflow) to add a summary of build output to other Zulip posts about workflow results. This allows us to more easily see the origin of a failure. This requires redoing the script a little to make it a bit more flexible, and the output is slightly reformatted to become consistent across the various workflows (4 of them that post to Zulip). We don't do so for the nightly-testing failures, since those run in a different workflow, and it would be a lot of work to access the command output from another workflow. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	CI merge-conflict	93/69	.github/workflows/daily.yml,.github/workflows/nightly-docgen.yml,.github/workflows/nightly-regression-report.yml,scripts/zulip_build_report.sh	4	2	['github-actions', 'mathlib4-merge-conflict-bot']	nobody	16-52021 16 days ago	31-15503 1 month ago	41-48286 41 days
22662	plp127 author:plp127	feat: Localization.Away.lift (computably)	This PR adds `Localization.Away.lift'` and `Localization.Away.lift`, computable alternatives to `Localization.awayLift`. --- - [x] depends on: #24791 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	74/0	Mathlib/RingTheory/Localization/Away/Basic.lean	1	18	['eric-wieser', 'github-actions', 'grunweg', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'plp127', 'vihdzp']	kim-em assignee:kim-em	16-2056 16 days ago	16-2057 16 days ago	257-28368 257 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	t-topology merge-conflict	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	16-1884 16 days ago	16-1885 16 days ago	177-43425 177 days
25974	scholzhannah author:scholzhannah	feat(Topology/Compactness/CompactlyCoherentSpace): compact coherentification (k-ification)	This PR defines the notion of turning an arbitrary topological space into a compactly coherent space. Compactly coherent spaces are commonly referred to as "compactly generated spaces" or "k-spaces" in the literature while the operation of turning a space into such as space is called the "k-ification". There are however three different notions that are described with this name. To disambiguate we use the names "compactly coherent space" and "compactcoherentification" here. See [this wikipedia page](https://en.wikipedia.org/wiki/Compactly_generated_space) for an explanation of these notions. This PR continues the work from #25318. Original PR: https://github.com/leanprover-community/mathlib4/pull/25318 Co-authored-by: Floris van Doorn	large-import t-topology merge-conflict	174/5	Mathlib/Topology/Compactness/CompactlyCoherentSpace.lean	1	5	['github-actions', 'joelriou', 'mathlib4-merge-conflict-bot', 'scholzhannah']	ADedecker assignee:ADedecker	16-1716 16 days ago	16-1717 16 days ago	148-47112 148 days
26332	Timeroot author:Timeroot	feat(ModelTheory/Definability): TermDefinable functions	This PR continues the work from #23506. Original PR: https://github.com/leanprover-community/mathlib4/pull/23506	t-logic merge-conflict	145/0	Mathlib/Data/Rel.lean,Mathlib/ModelTheory/Definability.lean,scripts/noshake.json	3	30	['Timeroot', 'github-actions', 'mathlib4-merge-conflict-bot', 'staroperator']	fpvandoorn assignee:fpvandoorn	16-1531 16 days ago	16-1532 16 days ago	145-80722 145 days
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	t-data merge-conflict	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	16-1526 16 days ago	16-1527 16 days ago	148-922 148 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/)	t-data merge-conflict	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	16-1362 16 days ago	16-1363 16 days ago	133-25807 133 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/)	new-contributor t-dynamics merge-conflict	401/0	Mathlib.lean,Mathlib/Dynamics/BirkhoffSum/Pointwise.lean	2	14	['D-Thomine', 'github-actions', 'leanprover-community-bot-assistant', 'lua-vr', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	urkud assignee:urkud	16-1359 16 days ago	16-1360 16 days ago	91-66923 91 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/)	t-order merge-conflict	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']	YaelDillies assignee:YaelDillies	16-1199 16 days ago	16-1200 16 days ago	114-58354 114 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.	new-contributor t-combinatorics merge-conflict	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	16-1057 16 days ago	16-1058 16 days ago	102-43516 102 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/)	new-contributor t-combinatorics merge-conflict	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	16-904 16 days ago	16-905 16 days ago	86-45080 86 days
29235	yoh-tanimoto author:yoh-tanimoto	feat(Topology/Algebra/Module/ClosedSubmodule): add `mapEquiv`, a variation of `ClosedSubmodule.map` for CLE	add `ClosedSubmodule.mapEquiv` for continuous linear equivalence. In this case, a closed submodule is mapped to a closed submodule, so the definitions are easier and behave nicely with `closure` and `⊔`. motivation: needed to define standard subspaces in a Hilbert space (scalar multiplication by `Complex.I`) #29251 https://ems.press/content/serial-article-files/48171 - [x] depends on: #29230 for `Lattice` `CompleteLattice`	t-topology merge-conflict	69/1	Mathlib/Topology/Algebra/Module/ClosedSubmodule.lean	1	3	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	fpvandoorn assignee:fpvandoorn	16-890 16 days ago	16-891 16 days ago	67-57008 67 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 $(B₁.charpoly_eq.symm.trans B₂.charpoly_eq)) rw [Polynomial.roots_prod, Polynomial.roots_prod] at this; rotate_left · simp [Finset.prod_ne_zero_iff, Polynomial.X_sub_C_ne_zero] · simp [Finset.prod_ne_zero_iff, Polynomial.X_sub_C_ne_zero] simp_rw [Polynomial.roots_X_sub_C, Multiset.bind_singleton] at this exact ⟨Multiset.equivOfMapUnivEq this, (Multiset.compTriple_equivOfMapUnivEq this).comp_eq.symm⟩ ``` Co-authored-by: Aristotle Harmonic --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data merge-conflict	35/0	Mathlib/Data/Multiset/Fintype.lean	1	9	['Ruben-VandeVelde', 'github-actions', 'llllvvuu', 'mathlib4-merge-conflict-bot', 'vihdzp', 'wwylele']	pechersky assignee:pechersky	16-866 16 days ago	16-867 16 days ago	69-23592 69 days
29610	llllvvuu author:llllvvuu	feat(LinearAlgebra): define LinearMap.Eigenbasis	Some theorems are left TODO for follow-up work. The definition is from @eric-wieser ([#Is there code for X? > diagonalizable linear maps @ 💬](https://leanprover.zulipchat.com/#narrow/channel/217875-Is-there-code-for-X.3F/topic/diagonalizable.20linear.20maps/near/539163222)). Co-authored-by: Aristotle Harmonic --- - [x] depends on: #29420 (golfs some `[Nontrivial R]` assumptions) - [x] depends on: #29791 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	455/5	Mathlib.lean,Mathlib/Analysis/InnerProductSpace/Spectrum.lean,Mathlib/LinearAlgebra/Eigenbasis.lean,Mathlib/LinearAlgebra/FreeModule/PID.lean,Mathlib/Order/CompleteLattice/Basic.lean	5	30	['github-actions', 'kckennylau', 'llllvvuu', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	joelriou assignee:joelriou	16-301 16 days ago	16-302 16 days ago	22-46437 22 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/)	new-contributor t-combinatorics merge-conflict	476/0	Mathlib.lean,Mathlib/Combinatorics/Digraph/Maps.lean	2	2	['github-actions', 'mathlib4-merge-conflict-bot']	awainverse assignee:awainverse	16-270 16 days ago	16-271 16 days ago	55-55764 55 days
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	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	16-263 16 days ago	16-264 16 days ago	41-49356 41 days
30131	fpvandoorn author:fpvandoorn	feat: alias_in attribute	* A small wrapper for adding an alias of a declaration in another namespace. * application time `.afterCompilation` is necessary for `#eval` to work correctly * Docstrings are copied, jump-to-definition works (no test in the test file, but tested locally) * To be used for CW-complexes, where lemmas are frequently duplicated between `RelCWComplex` and `CWComplex`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) cc @scholzhannah	t-meta merge-conflict	93/0	Mathlib.lean,Mathlib/Util/AliasIn.lean,MathlibTest/Util/AliasIn.lean	3	14	['JovanGerb', 'fpvandoorn', 'github-actions', 'mathlib4-merge-conflict-bot']	JovanGerb assignee:JovanGerb	16-235 16 days ago	16-235 16 days ago	47-55790 47 days
30233	Komyyy author:Komyyy	refactor(Topology/Sequences): generalize seq-compactness lemmas to metrizable space	* [`IsSeqCompact.isCompact`](https://leanprover-community.github.io/mathlib4_docs/Mathlib/Topology/Sequences.html#IsSeqCompact.isCompact) * [`UniformSpace.isCompact_iff_isSeqCompact`](https://leanprover-community.github.io/mathlib4_docs/Mathlib/Topology/Sequences.html#UniformSpace.isCompact_iff_isSeqCompact) * [`UniformSpace.compactSpace_iff_seqCompactSpace`](https://leanprover-community.github.io/mathlib4_docs/Mathlib/Topology/Sequences.html#UniformSpace.compactSpace_iff_seqCompactSpace) These are lemmas on uniform spaces which has countable uniformity, so can be generalized to pseudo-metrizable space. From [CLT](https://github.com/RemyDegenne/CLT) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import t-topology merge-conflict	20/7	Mathlib/Topology/Sequences.lean,docs/overview.yaml,docs/undergrad.yaml	3	2	['github-actions', 'mathlib4-merge-conflict-bot']	grunweg assignee:grunweg	16-100 16 days ago	16-101 16 days ago	41-80880 41 days
30355	kckennylau author:kckennylau	feat(Logic): graded functions	This PR defines a class of graded functions, called `GradedFunLike`. It is intended to be used in #30312 to characterise a class of graded ring homomorphisms, where it is invoked as `[GradedFunLike F 𝒜 ℬ] [RingHomClass F A B]`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data merge-conflict	41/0	Mathlib.lean,Mathlib/Data/FunLike/Graded.lean	2	2	['github-actions', 'mathlib4-merge-conflict-bot']	nobody	16-82 16 days ago	16-83 16 days ago	41-25826 41 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/)	t-meta merge-conflict	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	15-81691 15 days ago	15-81692 15 days ago	11-75498 11 days
26770	Jun2M author:Jun2M	feat(Combinatorics/Graph): subgraph relations on `Graph`	This PR creates a new file `Combinatorics/Graph/Subgraph.lean`. In it, the PR introduces a partial order on graphs by subgraph relation, defines relations `IsInducedSubgraph`, `IsSpanningSubgraph` and `IsClosedSubgraph`. Further, it introduce operations `EdgeRestrict`, `EdgeDelete`, `induce` and `VertexDelete`. Co-authored-by: Peter Nelson --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-combinatorics merge-conflict	375/1	Mathlib.lean,Mathlib/Combinatorics/Graph/Basic.lean,Mathlib/Combinatorics/Graph/Subgraph.lean	3	2	['github-actions', 'mathlib4-merge-conflict-bot']	awainverse assignee:awainverse	15-59952 15 days ago	16-1382 16 days ago	137-36187 137 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/)	t-category-theory merge-conflict	1372/19	Mathlib.lean,Mathlib/CategoryTheory/Functor/KanExtension/Basic.lean,Mathlib/CategoryTheory/Monoidal/DayConvolution.lean,Mathlib/CategoryTheory/Monoidal/DayConvolution/DayFunctor.lean	4	n/a	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	15-59918 15 days ago	unknown	unknown
28708	sjh227 author:sjh227	feat (Data): edit DoublyStochastic, add Stochastic to matrix	edit DoublyStochastic add Stochastic --- Add the file Stochastic to matrix. Edit DoublyStochastic so that it depends on Stochastic along with a new lemma	t-data new-contributor merge-conflict	249/1	Mathlib.lean,Mathlib/Data/Matrix/DoublyStochastic.lean,Mathlib/Data/Matrix/Stochastic.lean	3	26	['github-actions', 'j-loreaux', 'mathlib4-merge-conflict-bot', 'sjh227']	nobody	15-59798 15 days ago	99-49770 3 months ago	0-78027 21 hours
29281	plp127 author:plp127	doc: `Fin.natAdd_castLEEmb`	Change the docstring of `Fin.natAdd_castLEEmb` which confused me when I read it so I rewrote it. PS. this doesn't really follow the naming convention since data should be in `camelCase` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data merge-conflict	2/3	Mathlib/Data/Fin/Embedding.lean	1	2	['github-actions', 'mathlib4-merge-conflict-bot']	nobody	15-59728 15 days ago	74-69627 2 months ago	18-38918 18 days
30855	Ruben-VandeVelde author:Ruben-VandeVelde	fix: deprecate IsTotal in favour of Std.Total	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	RFC merge-conflict	208/111	Mathlib/Algebra/Group/Basic.lean,Mathlib/Algebra/Order/Archimedean/Class.lean,Mathlib/Algebra/Order/GroupWithZero/Canonical.lean,Mathlib/Algebra/Order/Ring/Canonical.lean,Mathlib/Data/Finset/Sort.lean,Mathlib/Data/List/Sort.lean,Mathlib/Data/Multiset/Sort.lean,Mathlib/Data/Nat/PartENat.lean,Mathlib/Data/Ordmap/Invariants.lean,Mathlib/Data/Ordmap/Ordset.lean,Mathlib/Data/Prod/Basic.lean,Mathlib/Data/Prod/Lex.lean,Mathlib/Data/Real/Basic.lean,Mathlib/Data/Sigma/Lex.lean,Mathlib/Data/Sigma/Order.lean,Mathlib/Data/Sum/Order.lean,Mathlib/Logic/Encodable/Basic.lean,Mathlib/Order/Antisymmetrization.lean,Mathlib/Order/Basic.lean,Mathlib/Order/Comparable.lean,Mathlib/Order/Compare.lean,Mathlib/Order/Defs/Unbundled.lean,Mathlib/Order/Directed.lean,Mathlib/Order/Filter/FilterProduct.lean,Mathlib/Order/Lattice.lean,Mathlib/Order/PropInstances.lean,Mathlib/Order/RelClasses.lean,Mathlib/Order/RelIso/Basic.lean,Mathlib/Order/UpperLower/CompleteLattice.lean,Mathlib/Order/WithBot.lean,Mathlib/RingTheory/Valuation/ValuationRing.lean,Mathlib/RingTheory/Valuation/ValuationSubring.lean,Mathlib/Topology/EMetricSpace/BoundedVariation.lean	33	3	['github-actions', 'linesthatinterlace', 'mathlib4-merge-conflict-bot']	alexjbest assignee:alexjbest	14-28859 14 days ago	16-70923 16 days ago	24-78190 24 days
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.	t-algebra merge-conflict 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	25	['artie2000', 'eric-wieser', 'github-actions', 'j-loreaux', 'kckennylau', 'leanprover-bot', 'leanprover-radar', 'linesthatinterlace', 'mathlib4-merge-conflict-bot', 'pechersky']	joelriou assignee:joelriou	10-69017 10 days ago	10-69018 10 days ago	64-44898 64 days
24016	plp127 author:plp127	feat: fine uniformity	Adds the fine uniformity, and proves some properties. --- - [ ] depends on: #24096 for showing the induced topology is equal on completely regular spaces [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology merge-conflict	283/0	Mathlib.lean,Mathlib/Topology/UniformSpace/FineUniformity.lean,Mathlib/Topology/UniformSpace/Uniformizable.lean	3	3	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	10-20285 10 days ago	10-20286 10 days ago	2-85349 2 days
32242	vihdzp author:vihdzp	feat: missing instances for `OrderDual`/`Lex`/`Colex`	--- The `Nonempty` and `Inhabited` instances for `OrderDual` exist in `Order.Basic` already. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-order merge-conflict	14/16	Mathlib/Order/Synonym.lean	1	2	['github-actions', 'mathlib4-merge-conflict-bot']	nobody	3-1751 3 days ago	3-1752 3 days ago	2-55967 2 days
32210	ADedecker author:ADedecker	feat: iteratedFDeriv as a linear map on test functions	Add `TestFunction.iteratedFDeriv[WithOrder]LM`, analogous to [ContDiffMapSupportedIn.iteratedFDerivWithOrderLM](https://leanprover-community.github.io/mathlib4_docs/Mathlib/Analysis/Distribution/ContDiffMapSupportedIn.html#ContDiffMapSupportedIn.iteratedFDerivWithOrderLM) and [ContDiffMapSupportedIn.iteratedFDerivLM](https://leanprover-community.github.io/mathlib4_docs/Mathlib/Analysis/Distribution/ContDiffMapSupportedIn.html#ContDiffMapSupportedIn.iteratedFDerivLM) --- Co-authored-by: @luigi-massacci [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-analysis merge-conflict	109/2	Mathlib/Analysis/Distribution/TestFunction.lean	1	2	['github-actions', 'mathlib4-merge-conflict-bot']	nobody	1-39568 1 day ago	3-75652 3 days ago	6-63454 6 days
32401	ADedecker author:ADedecker	feat: monotonicity of D^n(U) in n and in U as CLMs	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-analysis merge-conflict	176/3	Mathlib/Analysis/Distribution/ContDiffMapSupportedIn.lean,Mathlib/Analysis/Distribution/TestFunction.lean	2	n/a	['ADedecker', 'github-actions', 'mathlib4-merge-conflict-bot']	nobody	1-39059 1 day ago	unknown	unknown
30441	linesthatinterlace author:linesthatinterlace	refactor(`Data/List/Sort`): deprecate and replace `List.Sorted`	Deprecates `Sorted` and defines new special-case predicates to be used for preorders. `List.Sorted` is essentially an irrelevant definition, as it is identical to List.Pairwise, and we have some results about Sorted which also always apply to Pairwise or do so under certain conditions (and vice versa). We also commonly use Sorted to talk specifically about `<` and `<=`, which can be somewhat unwieldy. As a result, this PR does the following. ### Deprecate List.Sorted `List.Sorted` is currently just a synonym of `List.Pairwise`, but it isn't even an `abbrev`. We deprecate it here along with theorems that are just repeats from Pairwise. ### Separate out InsertionSort and MergeSort content We extract the theorems about insertion sort and merge sort that currently exist in the context of `List.Sorted` - they are currently in the same file but I think they could go elsewhere, potentially even into `Batteries` where I think they would naturally fit - they aren't really mathematical in nature IMO. ### Define `Sorted` predicates. It is useful to have predicates `SortedLT`, `SortedLE`, `SortedGT` and `SortedGE`, which correspond to exactly what they sound like. These are equivalent to suitable `Pairwise` statements, but that is not how they are defined - one could equivalently define them using `IsChain`, or, as I do here, using monotonicity of `List.get`. While the latter is how they are defined, I use irreducible definitions - it is not permitted to use the definitions directly. Instead, API is provided so that you can easily move to/from monotonicity statements, Pairwise statements, and IsChain statements. You don't destructure lists directly here: to prove things from, say, (a :: b :: l).sortedLT, one probably accesses IsChain lemmas to extract things from this statement. But one can also use the monotonicty API to prove things usefully. `Data.List.Sorted` contains all of this and I think it exhibits my thinking on what should be possible. I've actually changed my mind a couple of times on how to actually define these - one could use Pairwise, IsChain or Monotone etc. to taste - but it doesn't matter, because the API is robust enough that it changes very little once one establishes the core set of facts/equivalence between these. ### In particular, add better decidability instance [List.decidableSorted](https://leanprover-community.github.io/mathlib4_docs/Mathlib/Data/List/Sort.html#List.decidableSorted) has the fundamental issue that `List.Sorted` seems conceptually meant for transitive relations, but the instance of Decidable it uses uses Pairwise's decidability, not IsChain's. This is a problem because the latter is O(n) and the former is O(n^2), where n is the length of the list. It's not a major deal one might think - but I think being able to efficiently check whether something is <-sorted or <=-sorted is important. ### Adapt library to changes I think nearly everywhere we actually use* `List.Sorted` it is in the context of (<) or (<=), so I've changed to using these specific predicates. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data merge-conflict	995/638	Mathlib.lean,Mathlib/AlgebraicTopology/SimplexCategory/GeneratorsRelations/NormalForms.lean,Mathlib/Analysis/Convex/BetweenList.lean,Mathlib/Analysis/Matrix/Spectrum.lean,Mathlib/Combinatorics/Young/YoungDiagram.lean,Mathlib/Data/Fin/Tuple/Sort.lean,Mathlib/Data/Finset/Sort.lean,Mathlib/Data/List/Nodup.lean,Mathlib/Data/List/NodupEquivFin.lean,Mathlib/Data/List/OfFn.lean,Mathlib/Data/List/Pairwise.lean,Mathlib/Data/List/Sort.lean,Mathlib/Data/Multiset/Sort.lean,Mathlib/Data/Nat/BitIndices.lean,Mathlib/Data/Nat/Factors.lean,Mathlib/Deprecated/Sort.lean,Mathlib/Logic/Equiv/Finset.lean,Mathlib/Logic/Equiv/Multiset.lean,Mathlib/NumberTheory/ADEInequality.lean,Mathlib/NumberTheory/Divisors.lean,Mathlib/Order/JordanHolder.lean,Mathlib/Order/RelSeries.lean,Mathlib/Order/Synonym.lean,Mathlib/SetTheory/Ordinal/Basic.lean,Mathlib/SetTheory/Ordinal/CantorNormalForm.lean,Mathlib/Tactic/Simproc/Factors.lean,Mathlib/Topology/Category/Profinite/Nobeling/Basic.lean,Mathlib/Topology/Category/Profinite/Nobeling/Span.lean	28	85	['Vierkantor', 'github-actions', 'joelriou', 'linesthatinterlace', 'mathlib-bors', 'mathlib4-merge-conflict-bot', 'riccardobrasca', 'vihdzp']	Vierkantor assignee:Vierkantor	0-71124 19 hours ago	0-74886 20 hours ago	36-13100 36 days
32127	CoolRmal author:CoolRmal	feat: use IndexedPartition.piecewise to create simple/measurable/strongly measurable functions	The lemmas proved in this PR are needed in https://github.com/RemyDegenne/brownian-motion/pull/304. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	brownian large-import t-measure-probability merge-conflict	122/4	Mathlib/Data/Setoid/Partition.lean,Mathlib/MeasureTheory/Function/SimpleFunc.lean,Mathlib/MeasureTheory/Function/StronglyMeasurable/Basic.lean,Mathlib/MeasureTheory/MeasurableSpace/Basic.lean	4	17	['CoolRmal', 'EtienneC30', 'github-actions', 'hanwenzhu', 'mathlib4-merge-conflict-bot']	EtienneC30 assignee:EtienneC30	0-47953 13 hours ago	0-47954 13 hours ago	8-9383 8 days

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/)	new-contributor t-algebra awaiting-author label:t-algebra$	5/0	Mathlib/Algebra/Group/Basic.lean	1	3	['eric-wieser', 'github-actions', 'kim-em']	nobody	476-78854 1 year ago	476-78854 1 year ago	6-38745 6 days
11090	pangelinos author:pangelinos	feat: define spectral spaces and prove that a quasi-compact open of a spectral space is spectral	Define spectral spaces and prove that a quasi-compact open of a spectral space is spectral. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-topology please-adopt good first issue	69/0	Topology/Spectral/basic.lean	1	15	['YaelDillies', 'adomani', 'j-loreaux', 'jcommelin', 'kim-em', 'pangelinos']	nobody	472-63106 1 year ago	476-76032 1 year ago	16-44803 16 days
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/)	new-contributor t-category-theory awaiting-author	40/0	Mathlib/CategoryTheory/EpiMono.lean	1	3	['github-actions', 'joelriou', 'mattrobball']	nobody	459-38598 1 year ago	490-84257 1 year ago	7-3203 7 days
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/)	new-contributor t-combinatorics WIP	24/0	Mathlib/Combinatorics/SimpleGraph/Map/Finite.lean	1	11	['awueth', 'github-actions', 'jcommelin', 'kim-em', 'urkud']	nobody	408-57600 1 year ago	408-57600 1 year ago	31-44440 31 days
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/)	new-contributor t-algebra awaiting-author label:t-algebra$	78/0	Mathlib/Algebra/Group/Defs.lean	1	13	['github-actions', 'hannahfechtner', 'jcommelin', 'kbuzzard', 'kim-em', 'trivial1711']	nobody	318-82135 10 months ago	318-82135 10 months ago	69-35596 69 days
20797	vbeffara author:vbeffara	feat(Topology/Covering): CM version of eq_of_comp_eq	Add equivalents of the lemmas `IsCoveringMap.eq_of_comp_eq` and `IsCoveringMap.const_of_comp_CM` for the case of bundled `ContinuousMap` parameters. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-topology easy awaiting-author	9/1	Mathlib/Topology/Covering.lean	1	4	['github-actions', 'ocfnash', 'vbeffara']	nobody	318-68900 10 months ago	319-69853 10 months ago	2-77310 2 days
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/)	new-contributor t-algebra awaiting-author label:t-algebra$	43/0	Mathlib/Algebra/BigOperators/Group/Finset/Basic.lean	1	1	['github-actions', 'j-loreaux']	nobody	288-33742 9 months ago	288-33742 9 months ago	13-33168 13 days
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/)	new-contributor t-algebra t-category-theory WIP 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	216-2482 7 months ago	216-2482 7 months ago	0-0 0 seconds
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 new-contributor awaiting-author	2/24	Mathlib/Computability/EpsilonNFA.lean	1	2	['YaelDillies', 'github-actions', 'urkud']	nobody	207-80740 6 months ago	207-80740 6 months ago	27-52316 27 days
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/)	awaiting-zulip t-computability new-contributor	101/10	Mathlib/Computability/EpsilonNFA.lean,Mathlib/Computability/NFA.lean	2	41	['YaelDillies', 'github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'meithecatte']	nobody	180-44763 5 months ago	180-44764 5 months ago	34-10595 34 days
27069	FrankieNC author:FrankieNC	feat(Analysis/MetricSpace/HausdorffDimension): prove dimH of intervals and segments is 1	Add theorems `dimH_Icc01` and `dimH_segment` showing that the Hausdorff dimension of the unit interval [0,1] and of any non-degenerate real segment is 1. The key idea is that the segment is the image of [0,1] under a bi-Lipschitz map. We explicitly construct this map and prove it is both Lipschitz and antilipschitz, allowing us to transfer the dimension result from the unit interval. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-topology awaiting-author	63/0	Mathlib/Topology/MetricSpace/HausdorffDimension.lean	1	10	['AntoineChambert-Loir', 'FrankieNC', 'github-actions', 'grunweg']	nobody	144-43050 4 months ago	144-55534 4 months ago	0-13398 3 hours
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	new-contributor t-combinatorics awaiting-author	14/0	Mathlib/Combinatorics/SimpleGraph/Subgraph.lean	1	3	['b-mehta', 'github-actions', 'xcloudyunx']	b-mehta assignee:b-mehta	115-13987 3 months ago	115-28067 3 months ago	25-83942 25 days
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/)	will-close-soon new-contributor t-analysis awaiting-author WIP help-wanted	411/0	Mathlib/PlaceHolder/ToeplitzHausdorff.lean,Mathlib/PlaceHolder/ToeplitzHausdorff_v2.lean	2	11	['faenuccio', 'ggranberry', 'github-actions']	faenuccio assignee:faenuccio	113-76511 3 months ago	113-76714 3 months ago	4-24257 4 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/)	t-data new-contributor awaiting-author	326/0	Mathlib/Data/Nat/Choose/AbelBinomial.lean	1	28	['ElifUskuplu', 'FrankieNC', 'github-actions', 'iu-isgood']	nobody	103-58819 3 months ago	127-36716 4 months ago	0-533 8 minutes
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/)	new-contributor t-algebra awaiting-author label:t-algebra$	10/0	Mathlib/LinearAlgebra/Projection.lean	1	7	['PSchwahn', 'github-actions', 'joelriou', 'kckennylau']	joelriou assignee:joelriou	87-30187 2 months ago	87-61290 2 months ago	73-43225 73 days
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/)	new-contributor t-differential-geometry awaiting-author	36/0	Mathlib/Geometry/Manifold/ContMDiff/Defs.lean	1	13	['bwangpj', 'girving', 'github-actions', 'grunweg', 'kbuzzard', 'sgouezel']	sgouezel assignee:sgouezel	86-44942 2 months ago	86-85377 2 months ago	27-76128 27 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/)	new-contributor t-measure-probability awaiting-author	8/0	Mathlib/MeasureTheory/Integral/Bochner/Set.lean	1	6	['RemyDegenne', 'github-actions', 'sgouezel', 'thefundamentaltheor3m']	nobody	84-60811 2 months ago	175-68644 5 months ago	0-11893 3 hours
28175	dsfxcimk author:dsfxcimk	feat: exterior angle theorem	Add Exterior angle theorem --- The Exterior Angle Theorem states that the exterior angle of a triangle equals the sum of the two non-adjacent interior angles. I plan to place this in Mathlib.Geometry.Euclidean.Triangle [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-euclidean-geometry awaiting-author	10/0	Mathlib/Geometry/Euclidean/Triangle.lean,docs/1000.yaml	2	16	['FrankieNC', 'JovanGerb', 'dsfxcimk', 'github-actions', 'grunweg', 'mathlib4-merge-conflict-bot', 'themathqueen']	nobody	72-55898 2 months ago	86-68765 2 months ago	28-57160 28 days
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.	new-contributor t-analysis awaiting-author	383/0	Mathlib/Analysis/Complex/Residue/Basic.lean	1	17	['Periecle', 'github-actions', 'hrmacbeth', 'llllvvuu', 'loefflerd']	nobody	71-64289 2 months ago	82-66392 2 months ago	1-5255 1 day
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 [ ] depends on: #30141 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-topology	83/1	Mathlib/Topology/Baire/NonMeagre.lean,Mathlib/Topology/GDelta/Basic.lean	2	1	['github-actions']	nobody	63-36420 2 months ago	63-36422 2 months ago	63-36461 63 days
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 new-contributor awaiting-author	196/0	Archive.lean,Archive/Imo/Imo1975Q3.lean	2	36	['Antidite', 'LLaurance', 'github-actions', 'jsm28']	jsm28 assignee:jsm28	61-45079 2 months ago	61-45079 2 months ago	46-38383 46 days
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/)	t-group-theory new-contributor awaiting-author	6/0	Mathlib/GroupTheory/GroupAction/CardCommute.lean	1	17	['github-actions', 'kckennylau', 'plp127', 'tb65536']	tb65536 assignee:tb65536	45-64634 1 month ago	45-64634 1 month ago	8-8414 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/)	new-contributor t-combinatorics awaiting-author	16/0	Mathlib/Combinatorics/SimpleGraph/Trails.lean	1	6	['IvanRenison', 'github-actions', 'vlad902']	kmill assignee:kmill	44-28166 1 month ago	44-28166 1 month ago	148-3717 148 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 new-contributor awaiting-author	1310/0	Archive.lean,Archive/Imo/Imo2025Q1.lean	2	8	['github-actions', 'kim-em', 'mathlib4-merge-conflict-bot', 'zhuyizheng']	dwrensha assignee:dwrensha	43-63976 1 month ago	44-28680 1 month ago	65-5080 65 days
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	42-51598 1 month ago	42-51677 1 month ago	42-51725 42 days
30667	FrederickPu author:FrederickPu	Subgroup mul	Title: Algebra: pointwise products for subgroups Description: showed the point-wise product of disjoint subgroups is equivalent to their Cartesian product --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra awaiting-author label:t-algebra$	47/0	Mathlib/Algebra/Group/Subgroup/Pointwise.lean	1	10	['FrederickPu', 'eric-wieser', 'github-actions', 'plp127', 'tb65536']	nobody	37-64596 1 month ago	46-54630 1 month ago	0-46291 12 hours
28198	Sebi-Kumar author:Sebi-Kumar	feat(Analysis/InnerProductSpace/PiL2): Add instances for EuclideanSpace rank and EuclideanSpace being infinite	Add an instance for `Fact (Module.finrank 𝕜 (EuclideanSpace 𝕜 (Fin n)) = n)` which is needed to apply [stereographic'](https://leanprover-community.github.io/mathlib4_docs/Mathlib/Geometry/Manifold/Instances/Sphere.html#stereographic') to EuclideanSpace. Also add an instance for `Infinite (EuclideanSpace 𝕜 ι)` where `ι` is a nonempty fintype. I wasn't sure if these should go in separate pull requests, but they seemed similar enough to me. Thank you to Kenny Lau for the suggestions at [#mathlib4 > Instances for EuclideanSpace](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Instances.20for.20EuclideanSpace). --- To provide additional context, I am new to contributing to Mathlib, and I am doing so 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. My goal is to contribute that the `n`-sphere is simply connected for `n > 1`. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-analysis awaiting-author	6/0	Mathlib/Analysis/InnerProductSpace/PiL2.lean	1	7	['Ruben-VandeVelde', 'Sebi-Kumar', 'github-actions', 'kckennylau']	urkud assignee:urkud	31-80494 1 month ago	31-80494 1 month ago	82-22614 82 days
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/)	new-contributor t-algebra awaiting-author label:t-algebra$	94/0	Mathlib/LinearAlgebra/Matrix/Transvection.lean,MathlibTest/matrix.lean	2	3	['github-actions', 'riccardobrasca', 'zach1502']	nobody	31-75288 1 month ago	31-75288 1 month ago	42-32522 42 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/)	new-contributor t-combinatorics awaiting-author	9/4	Mathlib/Combinatorics/SimpleGraph/Basic.lean	1	3	['b-mehta', 'github-actions']	b-mehta assignee:b-mehta	31-8418 1 month ago	31-8418 1 month ago	31-69826 31 days
27229	WilliamCoram author:WilliamCoram	feat(GroupTheory/DoubleCoset): multiple lemmas	From FLT --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-group-theory FLT new-contributor	88/0	Mathlib/GroupTheory/DoubleCoset.lean	1	31	['Ruben-VandeVelde', 'WilliamCoram', 'github-actions', 'kim-em', 'mariainesdff', 'mathlib4-merge-conflict-bot']	mariainesdff assignee:mariainesdff	30-63317 1 month ago	31-54261 1 month ago	124-6401 124 days
29458	LiamSchilling author:LiamSchilling	feat(MvPolynomial/WeightedHomogenous): relate `weightedTotalDegree` to `degrees` and `degreeOf`	`weightedTotalDegree` is the most general notion of multivariate degree in mathlib. These theorems show that it specializes to `degrees` and `degreeOf` with specialized weights. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-ring-theory new-contributor awaiting-author	17/0	Mathlib/RingTheory/MvPolynomial/Homogeneous.lean	1	6	['LiamSchilling', 'chrisflav', 'github-actions']	chrisflav assignee:chrisflav	22-22134 22 days ago	72-79075 2 months ago	14-19311 14 days
31263	LiranShaul author:LiranShaul	feat: arbitrary product of injective modules is injective	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra awaiting-author label:t-algebra$	15/0	Mathlib/Algebra/Module/Injective.lean	1	12	['LiranShaul', 'erdOne', 'github-actions', 'joelriou', 'kbuzzard', 'mathlib4-merge-conflict-bot']	nobody	15-70319 15 days ago	15-77207 15 days ago	0-21724 6 hours
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/)	new-contributor t-algebra awaiting-author label:t-algebra$	1/0	Mathlib/Algebra/Group/Commutator.lean	1	2	['github-actions', 'grunweg']	nobody	15-61377 15 days ago	15-61377 15 days ago	6-8213 6 days
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/)	new-contributor t-combinatorics	375/0	Mathlib.lean,Mathlib/Combinatorics/Hypergraph/Basic.lean	2	53	['b-mehta', 'espottesmith', 'github-actions', 'jt496', 'lauramonk', 'mathlib4-merge-conflict-bot']	b-mehta assignee:b-mehta	15-61289 15 days ago	15-61311 15 days ago	96-38544 96 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/)	new-contributor t-combinatorics	391/0	Mathlib.lean,Mathlib/Combinatorics/DiHypergraph/Basic.lean	2	2	['github-actions', 'mathlib4-merge-conflict-bot']	b-mehta assignee:b-mehta	15-61243 15 days ago	15-61269 15 days ago	78-49667 78 days
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/)	t-data new-contributor awaiting-author	15/0	Mathlib/Data/Finset/Card.lean,Mathlib/Data/Set/Finite/Basic.lean	2	5	['Ruben-VandeVelde', 'github-actions']	nobody	15-60069 15 days ago	156-83292 5 months ago	13-85893 13 days
26881	emo916math author:emo916math	feat(Analysis/Calculus/Deriv/Star): a formula for `deriv (conj ∘ f ∘ conj)`	Added a lemma that `deriv (conj ∘ f ∘ conj) = conj ∘ deriv f ∘ conj`, proved by cases on whether the derivative mathematically exists or not. This PR replaces [#26805](https://github.com/leanprover-community/mathlib4/pull/26805); see discussion there. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-analysis awaiting-author	50/2	Mathlib/Analysis/Calculus/Deriv/Star.lean	1	15	['emo916math', 'github-actions', 'j-loreaux', 'kckennylau']	j-loreaux assignee:j-loreaux	15-59924 15 days ago	118-59672 3 months ago	31-70593 31 days
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/)	t-data new-contributor awaiting-author	22/0	Mathlib/Data/Rat/Lemmas.lean	1	33	['github-actions', 'kim-em', 'mathlib-bors', 'pechersky', 'sinianluoye', 'themathqueen']	pechersky assignee:pechersky	15-59841 15 days ago	39-18903 1 month ago	80-3629 80 days
29361	FlAmmmmING author:FlAmmmmING	feat: Catalan generating function as a formal power series	We introduce the Catalan generating function as a formal power series over `ℕ`. ## Main Definitions * `PowerSeries.catalanSeries`: The Catalan generating function as a power series. ## Main Results * `PowerSeries.sum_coeff_X_catalanSeries`: When `n` is a natural number, each term in the sum `coeff i X * catalan (n - i)` is 0 except for `i = 1`. * `PowerSeries.coeff_X_mul_catalanSeries`: The coefficient of `X * catalanSeries` at `X^n` is `catalan (n - 1)` when `n > 0`. * `PowerSeries.catalanSeries_one_add_X_mul_self_sq`: The Catalan generating function satisfies the equation `catalanSeries = 1 + X * catalanSeries ^ 2`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-ring-theory new-contributor awaiting-author	56/0	Mathlib.lean,Mathlib/RingTheory/PowerSeries/Catalan.lean	2	10	['FlAmmmmING', 'Ruben-VandeVelde', 'github-actions', 'kbuzzard', 'mathlib4-merge-conflict-bot', 'wwylele']	kbuzzard assignee:kbuzzard	15-48684 15 days ago	15-67300 15 days ago	70-34394 70 days
30609	FlAmmmmING author:FlAmmmmING	feat(Combinatorics/Enumerative/Catalan): large and small Schröder numbers	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-combinatorics awaiting-author	128/1	Mathlib/Combinatorics/Enumerative/Catalan.lean	1	6	['FlAmmmmING', 'SnirBroshi', 'YaelDillies', 'github-actions', 'mathlib4-merge-conflict-bot', 'plp127']	nobody	15-46951 15 days ago	15-67241 15 days ago	17-66663 17 days
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.	new-contributor t-measure-probability awaiting-author	13/0	Mathlib/MeasureTheory/PiSystem.lean	1	14	['EtienneC30', 'KiringYJ', 'dagurtomas', 'github-actions', 'ocfnash']	RemyDegenne assignee:RemyDegenne	15-46017 15 days ago	15-46017 15 days ago	138-3922 138 days
29434	ntapiam author:ntapiam	feat(NonAssoc/LieAdmissible): prove every ring/algebra is LieAdmissible	-awaiting-author	new-contributor t-algebra label:t-algebra$	27/6	Mathlib/Algebra/NonAssoc/LieAdmissible/Defs.lean	1	2	['github-actions', 'mathlib4-merge-conflict-bot']	nobody	13-44327 13 days ago	13-63700 13 days ago	85-57202 85 days
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/)	new-contributor awaiting-author	70/1	Mathlib/Analysis/LocallyConvex/Separation.lean,Mathlib/Analysis/RCLike/Lemmas.lean,Mathlib/Topology/Order/OrderClosed.lean	3	16	['faenuccio', 'fpvandoorn', 'github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'mcdoll', 'themathqueen', 'yuanyi-350']	faenuccio assignee:faenuccio	13-16394 13 days ago	13-23838 13 days ago	21-29486 21 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/)	new-contributor t-combinatorics	209/0	Mathlib/Combinatorics/SetFamily/Lindstrom.lean	1	2	['github-actions', 'mathlib4-merge-conflict-bot']	b-mehta assignee:b-mehta	12-68166 12 days ago	13-50597 13 days ago	46-17607 46 days
31366	FaffyWaffles author:FaffyWaffles	feat(Analysis/SpecialFunctions/StirlingRobbins): Robbins' sharp stepwise bound for stirlingSeq	Introduces `Mathlib.Analysis.SpecialFunctions.StirlingRobbins`, proving Robbins' sharp stepwise bound for the Stirling sequence. * Main theorem: `log_stirlingSeq_diff_le` * Improves the existing bound `1/(4k^2)` to the sharp `1/(12k(k+1))` * Adds helper lemmas on summability and geometric bounds * Complements `Stirling.lean` References: - https://leanprover-community.github.io/mathlib4_docs/Mathlib/Analysis/SpecialFunctions/Stirling.html - Robbins (1955), A Remark on Stirling’s Formula --- Note for Transparency: Assistance provided by AI tools (Claude and Aristotle) for drafting, text, and structure. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-analysis awaiting-author	64/5	Mathlib/Analysis/SpecialFunctions/Stirling.lean	1	15	['FaffyWaffles', 'github-actions', 'j-loreaux', 'mathlib4-merge-conflict-bot', 'tb65536']	nobody	9-37502 9 days ago	9-37502 9 days ago	4-57241 4 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	9-15808 9 days ago	16-10531 16 days ago	16-10571 16 days
31362	BeibeiX0 author:BeibeiX0	feat(partitions): generalized pentagonal numbers	feat(partitions): generalized pentagonal numbers and error term eₙ Introduce infrastructure around Euler’s pentagonal number theorem: * Define parity counters for strict partitions: - `p_even_distinct n` - `p_odd_distinct n` - `strict_partitions_parity_diff n := (p_even_distinct n : ℤ) - (p_odd_distinct n : ℤ)` * Generalized pentagonal numbers: - `generalizedPentagonalZ : ℤ → ℤ` with basic API (`gpn_nonneg`, `gpn_coe`) - `generalizedPentagonalNum : ℤ → ℕ` - parity lemma `even_neg_j_add_three_j_sq` and `even_neg_j_add_three_j_sq'` - search window equivalence `exists_j_iff_exists_j_in_range` - `Decidable (∃ j : ℤ, n = generalizedPentagonalZ j)` via a bounded range * Euler error term: - `error_term_e n : ℤ` (≔ `(-1)^{\|j\|}` if `n = generalizedPentagonalZ j` for some `j`, and `0` otherwise) * Finite product cut-off of the generating function: - `E n : PowerSeries ℤ := ∏_{k=1}^{n+1} (1 - X^k)` - lemma `coeff_E_eq_coeff_cutoff` Implementation notes: * Keep the integer-valued version `generalizedPentagonalZ` for arithmetic lemmas and signs; obtain the natural-number version via `Int.toNat`. * The bounded search lemma gives a small window `j ∈ [-(n+1), n+1]` for decidability. Motivation: * This is groundwork for proofs of Euler’s pentagonal number theorem and parity identities relating strict partitions to the error term. References: * https://en.wikipedia.org/wiki/Pentagonal_number_theorem	new-contributor t-combinatorics awaiting-author	258/0	Mathlib.lean,Mathlib/Combinatorics/Enumerative/PentagonalNumbers.lean	2	8	['BeibeiX0', 'dagurtomas', 'github-actions', 'mathlib4-merge-conflict-bot', 'wwylele']	awainverse assignee:awainverse	8-64722 8 days ago	8-64722 8 days ago	15-20162 15 days
31755	kaantahti author:kaantahti	feat(Combinatorics): Add Sperner's Lemma formalization	Complete formalization of Sperner's Lemma with rigorous proofs: - Main theorems: strong_sperner (odd count) and sperner (existence) - 13 fully proven auxiliary lemmas - 8 documented axioms for simplicial complex API - ~750 lines, zero sorries - Addresses issue #25231 This formalization proves both the strong version (odd number of panchromatic faces) and the existence version of Sperner's Lemma. The proof uses induction on dimension with a complete parity argument via boundary counting. The 8 axioms represent standard results from simplicial complex theory that are currently missing from mathlib4's geometric API. Each axiom is documented with mathematical justification and difficulty rating. Closes #25231	new-contributor t-combinatorics WIP	7725/0	Mathlib.lean,Mathlib/Analysis/Convex/SimplicialComplex/Boundary.lean,Mathlib/Combinatorics/Sperner.lean,PR_COMMENT_DRAFT.md	4	4	['LLaurance', 'github-actions', 'mathlib4-merge-conflict-bot']	nobody	8-64095 8 days ago	8-64095 8 days ago	8-13311 8 days
29508	zhuyizheng author:zhuyizheng	feat(MeasureTheory): FTC and integration by parts for absolutely continuous functions	Prove Fundamental Theorem of Calculus and integration by parts for absolutely continuous functions. Part of originally planned #29092. --- - [x] depends on: #29503 - [x] depends on: #29507 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-measure-probability awaiting-author	673/9	Mathlib.lean,Mathlib/Algebra/BigOperators/Group/Finset/Gaps.lean,Mathlib/Analysis/Analytic/OfScalars.lean,Mathlib/Analysis/Real/OfDigits.lean,Mathlib/MeasureTheory/Covering/Vitali.lean,Mathlib/MeasureTheory/Function/AbsolutelyContinuous.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral/AbsContFunc.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral/Basic.lean,Mathlib/Order/Interval/Finset/Gaps.lean,Mathlib/Topology/Algebra/InfiniteSum/Basic.lean,Mathlib/Topology/Algebra/InfiniteSum/Real.lean	11	6	['github-actions', 'jcommelin', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'zhuyizheng']	sgouezel assignee:sgouezel	8-28082 8 days ago	8-59402 8 days ago	2-7960 2 days
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.	new-contributor t-combinatorics awaiting-author	113/0	Mathlib.lean,Mathlib/Combinatorics/Enumerative/Polya.lean	2	7	['IvanRenison', 'alreadydone', 'github-actions', 'mathlib4-merge-conflict-bot']	awainverse assignee:awainverse	8-4470 8 days ago	8-4470 8 days ago	40-50241 40 days
32039	HugLycan author:HugLycan	Feat/positivity-zeroness	--- WIP... [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-meta WIP	528/131	Mathlib/Tactic/Positivity/Basic.lean,Mathlib/Tactic/Positivity/Core.lean,Mathlib/Tactic/Positivity/test_Basic.lean	3	2	['github-actions']	nobody	7-66940 7 days ago	7-66973 7 days ago	0-16 16 seconds
30344	Deep0Thinking author:Deep0Thinking	feat(MeasureTheory/Integral): add versions of `exists_eq_interval_average` and first mean value theorem for integrals	Add the First mean value theorem for (unordered) interval integrals on ℝ. - `exists_eq_const_mul_interval_integral_of_continuous_on_of_ae_nonneg` - `exists_eq_const_mul_interval_integral_of_continuous_on_of_nonneg` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-measure-probability	294/41	Mathlib.lean,Mathlib/MeasureTheory/Integral/IntervalAverage.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral/MeanValue.lean	3	10	['Deep0Thinking', 'github-actions', 'mathlib4-merge-conflict-bot', 'plp127']	kex-y assignee:kex-y	7-26037 7 days ago	10-41223 10 days ago	51-84560 51 days
32041	thomaskwaring author:thomaskwaring	feat(Combinatorics/SimpleGraph/Acyclic): every acyclic subgraph can be extended to a maximal one	We show that every acyclic subgraph can be extended to a maximal acyclic subgraph. ---	new-contributor t-combinatorics	32/0	Mathlib/Combinatorics/SimpleGraph/Acyclic.lean	1	1	['github-actions']	kmill assignee:kmill	7-26023 7 days ago	10-80128 10 days ago	10-80165 10 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/)	new-contributor t-analysis awaiting-author	14/0	Mathlib/Analysis/Convolution.lean	1	3	['github-actions', 'urkud']	nobody	7-2188 7 days ago	7-2188 7 days ago	0-82278 22 hours
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/)	new-contributor t-dynamics	114/6	Mathlib/Dynamics/Transitive.lean	1	4	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	sgouezel assignee:sgouezel	0-40082 11 hours ago	15-86115 15 days ago	14-66922 14 days
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/)	t-data new-contributor merge-conflict	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	472-63763 1 year ago	477-80005 1 year ago	54-52408 54 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.	t-data new-contributor merge-conflict please-adopt 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', 'leanprover-community-mathlib4-bot', 'urkud', 'vihdzp']	YaelDillies assignee:YaelDillies	400-39602 1 year ago	427-8393 1 year ago	12-48560 12 days
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/)	new-contributor t-order t-algebra merge-conflict 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	394-10168 1 year ago	394-10168 1 year ago	7-45599 7 days
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/)	new-contributor t-logic merge-conflict awaiting-author	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	391-52689 1 year ago	391-52689 1 year ago	0-19926 5 hours
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)	new-contributor t-logic merge-conflict awaiting-author	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	387-5121 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/)	new-contributor t-algebra merge-conflict 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	357-27538 11 months ago	363-62961 11 months ago	0-4534 1 hour
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/)	new-contributor t-topology merge-conflict awaiting-author	27/0	Mathlib/Topology/Order/DenselyOrdered.lean	1	8	['github-actions', 'vihdzp']	nobody	323-49550 10 months ago	323-49550 10 months ago	0-4704 1 hour
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	new-contributor t-combinatorics merge-conflict awaiting-author	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	322-68636 10 months ago	322-68636 10 months ago	9-13962 9 days
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/)	t-computability new-contributor merge-conflict awaiting-author	186/0	Mathlib.lean,Mathlib/Computability/Timed/InsertionSort.lean,Mathlib/Computability/Timed/Merge.lean	3	2	['github-actions', 'trivial1711']	nobody	322-34555 10 months ago	322-34555 10 months ago	33-11262 33 days
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/)	new-contributor t-algebra merge-conflict awaiting-author 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	317-56214 10 months ago	317-56215 10 months ago	36-2255 36 days
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/)	new-contributor t-measure-probability merge-conflict	203/40	Mathlib/MeasureTheory/Function/LpSeminorm/CompareExp.lean,Mathlib/MeasureTheory/Function/LpSpace.lean	2	1	['github-actions']	nobody	310-73562 10 months ago	310-73562 10 months ago	27-43617 27 days
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/)	new-contributor t-measure-probability merge-conflict awaiting-author	49/0	Mathlib/MeasureTheory/Function/L1Space.lean,Mathlib/MeasureTheory/Integral/IntegrableOn.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral.lean,Mathlib/MeasureTheory/Integral/SetIntegral.lean	4	30	['EtienneC30', 'arulandu', 'github-actions', 'loefflerd']	nobody	309-47995 10 months ago	309-47995 10 months ago	9-73631 9 days
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/)	t-computability new-contributor merge-conflict awaiting-author	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	293-64971 9 months ago	293-64971 9 months ago	37-29014 37 days
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) ```	new-contributor t-algebra t-category-theory merge-conflict label:t-algebra$	47/8	Mathlib/RepresentationTheory/FDRep.lean	1	19	['github-actions', 'grhkm21', 'joelriou', 'kim-em', 'mathlib-bors']	nobody	279-73569 9 months ago	279-73569 9 months ago	125-12755 125 days
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/)	new-contributor t-analysis merge-conflict awaiting-author	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	266-55409 8 months ago	266-55409 8 months ago	29-48368 29 days
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	new-contributor t-measure-probability t-analysis merge-conflict awaiting-author	60/1	Mathlib/MeasureTheory/Integral/FundThmCalculus.lean	1	3	['github-actions', 'hrmacbeth', 'victorliu5296']	nobody	242-85797 7 months ago	242-85797 7 months ago	51-85104 51 days
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/)	new-contributor t-analysis merge-conflict	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	231-41911 7 months ago	231-41911 7 months ago	25-60481 25 days
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/)	new-contributor t-algebra merge-conflict please-adopt awaiting-author label:t-algebra$	78/0	Mathlib/LinearAlgebra/UnitaryGroup.lean	1	8	['chrisflav', 'jcommelin', 'leanprover-community-bot-assistant']	nobody	181-25034 5 months ago	181-25036 5 months ago	9-22007 9 days
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/)	new-contributor t-meta merge-conflict awaiting-author	171/48	Mathlib/Tactic/Polyrith.lean,scripts/polyrith_sage.py	2	16	['eric-wieser', 'github-actions', 'hanwenzhu', 'kim-em', 'miguelmarco', 'mkoeppe']	nobody	174-17587 5 months ago	293-81949 9 months ago	27-65384 27 days
10541	Louddy author:Louddy	feat(Algebra/SkewMonoidAlgebra/Basic): add SkewMonoidAlgebra	# Skew Monoid algebras This file presents a skewed version of `Mathlib.Algebra.MonoidAlgebra.Basic`. ## Definition We define `SkewMonoidAlgebra k G := G →₀ k` attached with a skewed convolution product. Here, the product of two elements `f g : SkewMonoidAlgebra k G` is the finitely supported function whose value at `a` is the sum of `f x * (x • g y)` over all pairs `x, y` such that `x * y = a`. This will be used in a later PR to define skew polynomial rings. Co-authored-by: María Inés de Frutos Fernández <[mariaines.dff@gmail.com](mailto:mariaines.dff@gmail.com)> --- - [x] depends on: #15878 - [x] depends on: #19084 - [x] depends on: #22078 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra merge-conflict WIP label:t-algebra$	1624/0	Mathlib.lean,Mathlib/Algebra/Group/InjSurj.lean,Mathlib/Algebra/SkewMonoidAlgebra/Basic.lean,Mathlib/Algebra/SkewMonoidAlgebra/Lift.lean	4	105	['AntoineChambert-Loir', 'Louddy', 'YaelDillies', 'eric-wieser', 'fpvandoorn', 'github-actions', 'mariainesdff', 'mathlib4-dependent-issues-bot', 'mattrobball']	AntoineChambert-Loir assignee:AntoineChambert-Loir	148-69826 4 months ago	148-69828 4 months ago	179-12934 179 days
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 new-contributor t-category-theory merge-conflict WIP	720/0	Mathlib.lean,Mathlib/AlgebraicTopology/AugmentedSimplexCategory.lean,Mathlib/AlgebraicTopology/SimplicialObject.lean,Mathlib/Order/Category/FinLinOrd.lean	4	5	['TwoFX', 'YaelDillies', 'joelriou', 'jstoobysmith']	nobody	126-72888 4 months ago	126-72888 4 months ago	7-63215 7 days
18646	jxjwan author:jxjwan	feat(RingTheory): isotypic components	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-ring-theory new-contributor merge-conflict	308/0	Mathlib/Order/CompactlyGenerated/Basic.lean,Mathlib/RingTheory/Isotypic.lean,Mathlib/RingTheory/SimpleModule.lean	3	1	['github-actions']	nobody	121-81100 3 months ago	121-81100 3 months ago	20-16585 20 days
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. ---	new-contributor t-meta merge-conflict please-adopt modifies-tactic-syntax good first issue	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	111-81899 3 months ago	112-5255 3 months ago	22-16933 22 days
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/)	new-contributor t-measure-probability merge-conflict awaiting-author	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	55-54384 1 month ago	57-66854 1 month ago	1-21124 1 day
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/)	awaiting-zulip t-computability new-contributor merge-conflict awaiting-author	307/5	Mathlib/Computability/NFA.lean	1	27	['TpmKranz', 'YaelDillies', 'dupuisf', 'github-actions', 'leanprover-community-bot-assistant', 'meithecatte', 'rudynicolop']	nobody	17-35209 17 days ago	199-57768 6 months ago	45-84611 45 days
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/)	awaiting-zulip t-computability new-contributor merge-conflict awaiting-author	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	16-51450 16 days ago	16-51451 16 days ago	23-54870 23 days
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/)	awaiting-zulip t-computability new-contributor merge-conflict awaiting-author	159/0	Mathlib/Computability/DFA.lean,Mathlib/Computability/Language.lean	2	60	['EtienneC30', 'YaelDillies', 'github-actions', 'maemre', 'mathlib4-merge-conflict-bot', 'meithecatte', 'urkud']	EtienneC30 assignee:EtienneC30	16-50540 16 days ago	16-50541 16 days ago	48-67492 48 days
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/)	new-contributor t-analysis merge-conflict WIP help-wanted	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	16-2907 16 days ago	16-2907 16 days ago	0-0 0 seconds
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 t-meta merge-conflict modifies-tactic-syntax awaiting-author help-wanted	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	16-2643 16 days ago	16-2644 16 days ago	0-16 16 seconds
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/)	new-contributor t-algebra merge-conflict awaiting-author 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	16-2641 16 days ago	16-2642 16 days ago	26-39463 26 days
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/)	new-contributor t-category-theory merge-conflict awaiting-author	112/0	Mathlib.lean,Mathlib/CategoryTheory/Sites/CoveringFamilies.lean	2	21	['AnthonyBordg', 'adamtopaz', 'dagurtomas', 'github-actions', 'joelriou', 'mathlib4-merge-conflict-bot']	nobody	16-2512 16 days ago	16-2513 16 days ago	1-48443 1 day
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/)	t-algebraic-topology new-contributor merge-conflict WIP	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	15-60518 15 days ago	126-72932 4 months ago	1-20125 1 day
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/)	new-contributor t-algebra merge-conflict awaiting-author label:t-algebra$	91/0	Mathlib.lean,Mathlib/GroupTheory/SpecificGroups/BraidGroup/Basic.lean	2	22	['github-actions', 'hannahfechtner', 'jcommelin', 'joelriou']	nobody	15-60365 15 days ago	278-57880 9 months ago	15-40648 15 days
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/)	new-contributor t-meta merge-conflict WIP	34/4	Mathlib/Tactic/Simps/Basic.lean	1	11	['FrederickPu', 'YaelDillies', 'fpvandoorn', 'github-actions', 'leanprover-community-bot-assistant']	nobody	15-60302 15 days ago	132-41774 4 months ago	0-34081 9 hours
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/)	new-contributor t-topology merge-conflict	285/1	Mathlib.lean,Mathlib/Topology/ContinuousMap/MvPolynomial.lean,Mathlib/Topology/ContinuousMap/StoneWeierstrass.lean	3	1	['github-actions']	nobody	274-59583 8 months ago	274-59583 8 months ago	16-76141 16 days
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 new-contributor merge-conflict awaiting-author enhancement	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	n/a	['chrisflav', 'eric-wieser', 'github-actions', 'j-loreaux', 'markimunro']	nobody	248-4408 8 months ago	unknown	unknown
22701	ctchou author:ctchou	feat(Combinatorics): the Katona circle method	This file formalizes the Katona circle method. From PlainCombi (LeanCamCombi): https://github.com/YaelDillies/LeanCamCombi/blob/master/LeanCamCombi/PlainCombi/KatonaCircle.lean Co-authored-by: Yaël Dillies	new-contributor t-combinatorics merge-conflict	121/0	Mathlib.lean,Mathlib/Combinatorics/KatonaCircle.lean	2	1	['github-actions']	nobody	242-35352 7 months ago	242-35352 7 months ago	30-8337 30 days
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/)	new-contributor t-category-theory merge-conflict	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	239-67985 7 months ago	239-67986 7 months ago	58-20339 58 days
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/)	new-contributor t-topology merge-conflict awaiting-author	281/1	Mathlib.lean,Mathlib/Topology/Covering/Basic.lean,Mathlib/Topology/Covering/Lift.lean	3	9	['alreadydone', 'github-actions', 'grunweg', 'vbeffara']	nobody	238-70713 7 months ago	238-70713 7 months ago	55-53553 55 days
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/)	new-contributor t-algebra merge-conflict awaiting-author 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	231-38043 7 months ago	231-38043 7 months ago	13-60072 13 days
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/)	large-import new-contributor t-topology merge-conflict	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	191-53081 6 months ago	191-53083 6 months ago	35-30364 35 days
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/)	awaiting-zulip new-contributor t-algebraic-geometry merge-conflict	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	153-14348 5 months ago	153-14349 5 months ago	6-51040 6 days
25283	Brian-Nugent author:Brian-Nugent	feat: regular local rings	Adds regular local rings and proves they are integral domains. --- - [ ] depends on: #25280 - [ ] depends on: #25282 [![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$	871/0	.vscode/settings.json,Mathlib.lean,Mathlib/RingTheory/EmbeddingDimension.lean,Mathlib/RingTheory/LocalRingDimension.lean,Mathlib/RingTheory/RegularLocalRing.lean	5	6	['Brian-Nugent', 'github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'yuanyi-350']	nobody	153-14344 5 months ago	153-14344 5 months ago	11-84822 11 days
25485	VTrelat author:VTrelat	feat(SetTheory/ZFC/Naturals): define natural numbers in ZFC	Extend the model of ZFC with naturals: - define a set `Nat` of naturals following the usual construction (∅, {∅}, {∅, {∅}}, ...) - define a proper type `ZFNat` representing naturals - add theorems on usual algebraic properties of naturals - provide a recursor and induction schemes to define/prove by induction --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) - [ ] depend on: #25483	t-set-theory new-contributor merge-conflict	2095/0	Mathlib/Data/Set/Prod.lean,Mathlib/SetTheory/ZFC/Basic.lean,Mathlib/SetTheory/ZFC/Booleans.lean,Mathlib/SetTheory/ZFC/Naturals.lean	4	2	['github-actions', 'leanprover-community-bot-assistant']	nobody	122-79109 4 months ago	122-79109 4 months ago	29-51653 29 days
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/)	new-contributor t-meta merge-conflict	17/5	Mathlib/Tactic/ComputeDegree.lean,MathlibTest/ComputeDegree.lean	2	3	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	122-79079 4 months ago	122-79079 4 months ago	38-26044 38 days
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/)	large-import new-contributor t-number-theory 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	116-84641 3 months ago	116-84641 3 months ago	9-59130 9 days
25483	VTrelat author:VTrelat	chore(Data/Set/Prod, SetTheory/ZFC/Basic): add theorem prod_subset_of_prod and extend ZFC model	Required by @eric-wieser in #24281 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data new-contributor merge-conflict	103/0	Mathlib/Data/Set/Prod.lean,Mathlib/SetTheory/ZFC/Basic.lean	2	10	['Ruben-VandeVelde', 'VTrelat', 'github-actions', 'leanprover-community-bot-assistant']	nobody	113-66431 3 months ago	153-14338 5 months ago	29-56208 29 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/)	t-data new-contributor merge-conflict	24/26	Mathlib/Data/TypeVec.lean	1	7	['Equilibris', 'alexkeizer', 'github-actions', 'mathlib4-merge-conflict-bot']	nobody	104-31506 3 months ago	104-31507 3 months ago	13-49738 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/)	new-contributor merge-conflict	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	104-10826 3 months ago	126-73148 4 months ago	7-54661 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/)	new-contributor merge-conflict	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	103-59058 3 months ago	126-73149 4 months ago	7-62439 7 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 ---	new-contributor t-logic merge-conflict	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	86-65089 2 months ago	86-65090 2 months ago	21-3001 21 days
29092	zhuyizheng author:zhuyizheng	feat(MeasureTheory): add absolutely continuous functions, FTC and integration by parts	Add the ε-δ definition of absolutely continuous functions on a closed interval in ℝ. Prove Fundamental Theorem of Calculus and integration by parts for absolutely continuous functions. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-measure-probability merge-conflict awaiting-author	1376/0	Mathlib.lean,Mathlib/Analysis/Calculus/Deriv/Slope.lean,Mathlib/MeasureTheory/Function/AbsolutelyContinuous.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral/AbsContFunc.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral/DerivIntegrable.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral/LebesgueDifferetiationThm.lean,Mathlib/Topology/EMetricSpace/BoundedVariation.lean	7	6	['Ruben-VandeVelde', 'fpvandoorn', 'github-actions', 'grunweg', 'mathlib4-merge-conflict-bot']	nobody	67-37188 2 months ago	67-37189 2 months ago	0-24361 6 hours
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/)	new-contributor t-category-theory merge-conflict awaiting-author	17/0	Mathlib/CategoryTheory/Limits/Shapes/Products.lean	1	6	['chrisflav', 'github-actions', 'leanprover-community-bot-assistant', 'ppls-nd-prs', 'robin-carlier']	nobody	66-79333 2 months ago	153-12039 5 months ago	0-47665 13 hours
22657	Xmask19 author:Xmask19	feat: a graph is maximally acyclic iff it is a tree	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-combinatorics merge-conflict	86/0	Mathlib/Combinatorics/SimpleGraph/Acyclic.lean	1	7	['Rida-Hamadani', 'b-mehta', 'github-actions', 'grunweg', 'mathlib4-merge-conflict-bot']	b-mehta assignee:b-mehta	54-34572 1 month ago	54-34573 1 month ago	208-19611 208 days
28126	Sebi-Kumar author:Sebi-Kumar	feat(AlgebraicTopology/FundamentalGroupoid): relate equality in fundamental groupoid to homotopy	Prove the theorem `fromPath_eq_iff_homotopic` which shows that two paths are equal in the fundamental groupoid if and only if they are homotopic. Also add simp lemmas `fromPath_refl`, `fromPath_symm`, and `fromPath_trans`. Together, these allow one to prove two paths are homotopic by transferring to the fundamental groupoid and using the `aesop_cat` tactic. --- I would like to thank Kenny Lau for inspiring this code on Zulip at [#Is there code for X? > Using aesop_cat to prove paths are homotopic](https://leanprover.zulipchat.com/#narrow/channel/217875-Is-there-code-for-X.3F/topic/Using.20aesop_cat.20to.20prove.20paths.20are.20homotopic). Also, I would like to note that I am a newcomer when it comes to contributing to Mathlib, and that this code was written as a part of a formalization project at the University of Western Ontario under the supervision of Chris Kapulkin and Daniel Carranza (which is happening through the Fields Undergraduate Summer Research Program). - [ ] depends on: #28234 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebraic-topology new-contributor merge-conflict awaiting-author	121/141	Mathlib/AlgebraicTopology/FundamentalGroupoid/Basic.lean,Mathlib/AlgebraicTopology/FundamentalGroupoid/FundamentalGroup.lean,Mathlib/AlgebraicTopology/FundamentalGroupoid/InducedMaps.lean,Mathlib/AlgebraicTopology/FundamentalGroupoid/SimplyConnected.lean,Mathlib/CategoryTheory/Groupoid.lean,Mathlib/Topology/Covering.lean,Mathlib/Topology/Homotopy/HomotopyGroup.lean,Mathlib/Topology/Homotopy/Product.lean	8	11	['Sebi-Kumar', 'alreadydone', 'github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'mattrobball']	mattrobball assignee:mattrobball	47-48716 1 month ago	47-48717 1 month ago	14-30316 14 days
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/)	large-import new-contributor t-number-theory 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	37-84037 1 month ago	37-84037 1 month ago	53-41880 53 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/)	file-removed new-contributor t-topology merge-conflict awaiting-author	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	37-75767 1 month ago	37-75768 1 month ago	0-2409 40 minutes
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/)	awaiting-zulip t-computability new-contributor merge-conflict awaiting-author	218/2	Mathlib/Computability/Language.lean,Mathlib/Computability/NFA.lean	2	91	['EtienneC30', 'b-mehta', 'ctchou', 'github-actions', 'leanprover-community-bot-assistant', 'meithecatte', 'rudynicolop']	EtienneC30 assignee:EtienneC30	31-16893 1 month ago	199-56843 6 months ago	39-67601 39 days
26901	5hv5hvnk author:5hv5hvnk	feat: a simproc version of `compute_degree`	Wrap `compute_degree` in a simproc for use by simp. Closes #22219. ---	new-contributor awaiting-CI t-meta merge-conflict awaiting-author	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	28-55086 28 days ago	28-55087 28 days ago	2-71043 2 days
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/)	large-import awaiting-zulip new-contributor t-category-theory t-meta merge-conflict	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	22-18077 22 days ago	22-18077 22 days ago	1-18384 1 day
30962	WangYiran01 author:WangYiran01	feat(Combinatorics/Enumerative): add lattice path lemmas and counts	This PR adds definitions and theorems about monotone lattice paths: - Defines `pathCount`, `pathCountFrom`, `SubdiagProp`, and related structures. - Proves closed forms such as `pathCount_eq_closed`. - Adds Dyck/ballot subdiagonal property (`SubdiagProp`). All code builds successfully with `lake build`.	new-contributor t-combinatorics merge-conflict	64/0	Mathlib.lean,Mathlib/Combinatorics/Enumerative/RecLatticePath.lean	2	2	['github-actions', 'mathlib4-merge-conflict-bot']	awainverse assignee:awainverse	19-33588 19 days ago	19-33588 19 days ago	19-55009 19 days
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/)	awaiting-zulip t-computability new-contributor merge-conflict	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	16-2218 16 days ago	16-2219 16 days ago	75-77754 75 days
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/)	large-import new-contributor t-algebra awaiting-CI merge-conflict label:t-algebra$	169/0	Mathlib/Algebra/Free.lean	1	12	['YaelDillies', 'github-actions', 'mathlib4-merge-conflict-bot']	nobody	16-2078 16 days ago	16-2079 16 days ago	51-9403 51 days
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/)	t-computability new-contributor merge-conflict awaiting-author	70/0	Mathlib.lean,Mathlib/Computability/PDA.lean	2	35	['YaelDillies', 'github-actions', 'madvorak', 'mathlib4-merge-conflict-bot', 'shetzl']	nobody	16-2072 16 days ago	16-2073 16 days ago	20-81771 20 days
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/)	new-contributor t-category-theory merge-conflict awaiting-author	312/0	Mathlib.lean,Mathlib/CategoryTheory/Topos/Power.lean	2	3	['github-actions', 'joelriou', 'mathlib4-merge-conflict-bot']	b-mehta assignee:b-mehta	16-2063 16 days ago	16-2064 16 days ago	0-1528 25 minutes
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/)	t-computability new-contributor merge-conflict awaiting-author	383/0	Mathlib.lean,Mathlib/Computability/LeftmostDerivation.lean	2	55	['YaelDillies', 'github-actions', 'madvorak', 'mathlib4-merge-conflict-bot', 'shetzl']	YaelDillies assignee:YaelDillies	16-2061 16 days ago	16-2062 16 days ago	72-3718 72 days
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.	new-contributor t-analysis merge-conflict awaiting-author	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	16-2050 16 days ago	16-2051 16 days ago	30-77130 30 days
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/)	new-contributor t-combinatorics merge-conflict awaiting-author	187/0	Mathlib.lean,Mathlib/Combinatorics/SimpleGraph/Cycle.lean	2	42	['IvanRenison', 'github-actions', 'mathlib4-merge-conflict-bot', 'vlad902']	kmill assignee:kmill	16-1897 16 days ago	16-1898 16 days ago	123-22718 123 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/)	t-data new-contributor merge-conflict awaiting-author	129/1	Mathlib.lean,Mathlib/Data/List/Commutativity.lean,Mathlib/Data/List/Defs.lean,Mathlib/Data/List/Lemmas.lean	4	36	['MrSumato', 'github-actions', 'grunweg', 'mathlib4-merge-conflict-bot', 'plp127']	grunweg assignee:grunweg	16-1894 16 days ago	16-1895 16 days ago	29-59355 29 days
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.	new-contributor t-number-theory merge-conflict awaiting-author	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	16-1748 16 days ago	16-1749 16 days ago	17-63153 17 days
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/)	new-contributor t-analysis merge-conflict awaiting-author WIP	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	16-1536 16 days ago	16-1537 16 days ago	50-22679 50 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.	new-contributor t-algebra merge-conflict awaiting-author label:t-algebra$	465/0	Mathlib.lean,Mathlib/Algebra/Polynomial/ZMod.lean	2	3	['Ruben-VandeVelde', 'github-actions', 'mathlib4-merge-conflict-bot']	nobody	16-1388 16 days ago	16-1389 16 days ago	25-6199 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/)	new-contributor t-category-theory merge-conflict awaiting-author	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	16-1383 16 days ago	16-1384 16 days ago	62-83085 62 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/)	new-contributor t-dynamics merge-conflict	401/0	Mathlib.lean,Mathlib/Dynamics/BirkhoffSum/Pointwise.lean	2	14	['D-Thomine', 'github-actions', 'leanprover-community-bot-assistant', 'lua-vr', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	urkud assignee:urkud	16-1359 16 days ago	16-1360 16 days ago	91-66923 91 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/)	new-contributor t-combinatorics merge-conflict awaiting-author	1266/0	Mathlib.lean,Mathlib/Combinatorics/SimpleGraph/Triangle/IndependenceNumber.lean	2	10	['Pjotr5', 'github-actions', 'grunweg', 'mathlib4-merge-conflict-bot']	nobody	16-1346 16 days ago	16-1347 16 days ago	39-17587 39 days
27245	rirarika author:rirarika	feat: multivariate polynomial ring properties about irreducibility	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra merge-conflict awaiting-author label:t-algebra$	88/0	Mathlib.lean,Mathlib/Algebra/MvPolynomial/Irreducible.lean	2	6	['alreadydone', 'github-actions', 'mathlib4-merge-conflict-bot', 'mbkybky']	alreadydone assignee:alreadydone	16-1340 16 days ago	16-1341 16 days ago	109-22535 109 days
27261	Sebi-Kumar author:Sebi-Kumar	feat(Topology): add definition for subpaths	Define subpaths as restrictions of paths to subintervals, reparameterized to have domain `[0, 1]` and possibly with a reverse of direction. Prove their basic properties. This serves as an alternative to `Path.truncate` which is useful for the explicit construction of certain homotopies, in particular regarding the concatenation of subpaths. --- To provide additional context, this is my first time contributing to Mathlib, and I am doing so as a part of the Fields Undergraduate Summer Research Program hosted at Western University. My intention for this file is for it to be used when proving that the fundamental group of the sphere is trivial (following the proof from Hatcher's "Algebraic Topology"). [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-topology merge-conflict awaiting-author	146/0	Mathlib.lean,Mathlib/Topology/Subpath.lean	2	25	['ADedecker', 'FrankieNC', 'Sebi-Kumar', 'github-actions', 'mathlib4-merge-conflict-bot', 'themathqueen', 'wwylele']	ADedecker assignee:ADedecker	16-1216 16 days ago	16-1217 16 days ago	34-15767 34 days
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/)	new-contributor t-category-theory merge-conflict awaiting-author	70/1	Mathlib/CategoryTheory/Category/Factorisation.lean	1	13	['YunkaiZhang233', 'b-mehta', 'github-actions', 'mathlib4-merge-conflict-bot', 'robin-carlier']	nobody	16-1191 16 days ago	16-1192 16 days ago	0-3448 57 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/)	new-contributor t-differential-geometry merge-conflict awaiting-author	80/0	Mathlib.lean,Mathlib/Geometry/Manifold/ZeroDim.lean	2	14	['fyqing', 'github-actions', 'grunweg', 'mathlib4-merge-conflict-bot', 'tb65536']	grunweg assignee:grunweg	16-1189 16 days ago	16-1190 16 days ago	0-6418 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.	new-contributor t-combinatorics merge-conflict	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	16-1057 16 days ago	16-1058 16 days ago	102-43516 102 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/)	new-contributor t-combinatorics merge-conflict	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	16-904 16 days ago	16-905 16 days ago	86-45080 86 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/)	new-contributor t-combinatorics merge-conflict	476/0	Mathlib.lean,Mathlib/Combinatorics/Digraph/Maps.lean	2	2	['github-actions', 'mathlib4-merge-conflict-bot']	awainverse assignee:awainverse	16-270 16 days ago	16-271 16 days ago	55-55764 55 days
30121	idontgetoutmuch author:idontgetoutmuch	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/)	new-contributor t-differential-geometry merge-conflict awaiting-author	227/0	Mathlib.lean,Mathlib/Geometry/Manifold/PrincipalFiberBundle/PrincipalGBundle.lean	2	6	['github-actions', 'grunweg', 'mathlib4-merge-conflict-bot']	hrmacbeth assignee:hrmacbeth	16-237 16 days ago	16-238 16 days ago	25-22983 25 days
31102	JOSHCLUNE author:JOSHCLUNE	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/)	new-contributor merge-conflict	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	15-86127 15 days ago	15-86128 15 days ago	19-46677 19 days
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/)	new-contributor t-category-theory merge-conflict awaiting-author WIP	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	15-60275 15 days ago	283-31243 9 months ago	0-13879 3 hours
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/)	new-contributor t-category-theory merge-conflict awaiting-author	33/0	Mathlib/CategoryTheory/Limits/Types/Colimits.lean	1	5	['github-actions', 'joelriou', 'leanprover-community-bot-assistant', 'robertmaxton42']	nobody	15-60158 15 days ago	149-22161 4 months ago	8-28043 8 days
26156	oliver-butterley author:oliver-butterley	feat(MeasureTheory.VectorMeasure): add a definition of total variation for VectorMeasure	This PR adds variation for any `VectorMeasure` using a supremum definition. Currently mathlib has `TotalVariation` defined for a signed measure using the Hahn-Jordan decomposition, but this doesn't generalise. Motivation: generally this is an important concept but specifically as a step for proving RMK in the complex case which in turn is a step to prove the spectral theorem. Co-authored-by: @yoh-tanimoto This PR was migrated from #25442. PR divided into smaller pieces, this is just the definition without additional lemmas. PRs adding further results related to variation are: * #26160 * #26165 * #26168 (shows that for `SignedMeasures` the two definitions of variation coincide) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-measure-probability merge-conflict awaiting-author	358/0	Mathlib.lean,Mathlib/MeasureTheory/VectorMeasure/Variation/Defs.lean	2	33	['EtienneC30', 'github-actions', 'mathlib4-merge-conflict-bot', 'yoh-tanimoto']	EtienneC30 assignee:EtienneC30	15-60007 15 days ago	16-1564 16 days ago	42-9361 42 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/)	new-contributor t-combinatorics merge-conflict awaiting-author WIP	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	15-59820 15 days ago	15-59820 15 days ago	12-41939 12 days
28708	sjh227 author:sjh227	feat (Data): edit DoublyStochastic, add Stochastic to matrix	edit DoublyStochastic add Stochastic --- Add the file Stochastic to matrix. Edit DoublyStochastic so that it depends on Stochastic along with a new lemma	t-data new-contributor merge-conflict	249/1	Mathlib.lean,Mathlib/Data/Matrix/DoublyStochastic.lean,Mathlib/Data/Matrix/Stochastic.lean	3	26	['github-actions', 'j-loreaux', 'mathlib4-merge-conflict-bot', 'sjh227']	nobody	15-59798 15 days ago	99-49770 3 months ago	0-78027 21 hours
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/)	t-ring-theory new-contributor merge-conflict	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	15-59709 15 days ago	81-17039 2 months ago	3-7974 3 days
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/)	new-contributor t-algebra merge-conflict blocked-by-other-PR 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	436-49657 1 year ago	436-49657 1 year ago	0-0 0 seconds
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/)	new-contributor t-logic merge-conflict blocked-by-other-PR	300/7	Mathlib/ModelTheory/Complexity.lean,Mathlib/ModelTheory/Equivalence.lean,Mathlib/ModelTheory/Syntax.lean	3	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	428-45635 1 year ago	428-45636 1 year ago	0-1299 21 minutes
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/)	new-contributor t-logic merge-conflict blocked-by-other-PR	415/7	Mathlib/ModelTheory/Complexity.lean,Mathlib/ModelTheory/Equivalence.lean,Mathlib/ModelTheory/Syntax.lean	3	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	428-45635 1 year ago	428-45635 1 year ago	0-1045 17 minutes
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/)	new-contributor t-logic merge-conflict blocked-by-other-PR	525/7	Mathlib/ModelTheory/Complexity.lean,Mathlib/ModelTheory/Equivalence.lean,Mathlib/ModelTheory/Syntax.lean	3	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	428-45634 1 year ago	428-45634 1 year ago	0-613 10 minutes
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/)	t-data new-contributor merge-conflict awaiting-author blocked-by-other-PR	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	410-68292 1 year ago	410-68292 1 year ago	6-8380 6 days
11156	smorel394 author:smorel394	feat(LinearAlgebra/{TensorProductBasis,Dual}): basis and dual of `PiTensorProduct`	Construct a basis of a `PiTensorProduct` of modules given bases of the modules, and relationship between the dual of a `PiTensorProduct` and the `PiTensorProduct` of the duals. Main results: * `Basis.piTensorProduct` (in `LinearAlgebra/TensorProductBasis.lean`): Let `ι` be a `Fintype` and `M` be a family of modules indexed by `ι`. If `b i : κ i → M i` is a basis for every `i` in `ι`, then `fun (p : Π i, κ i) ↦ ⨂ₜ[R] i, b i (p i)` is a basis of `⨂[R] i, M i`. * `PiTensorProduct.dualDistrib` (in `LinearAlgebra/Dual.lean`): The canonical linear map from `⨂[R] i, Dual R (M i)` to `Dual R (⨂[R] i, M i)`, sending `⨂ₜ[R] i, f i` to the composition of `PiTensorProduct.map f` with the linear equivalence `⨂[R] i, R →ₗ R` given by multiplication. * `PiTensorProduct.dualDistribEquiv` (also in `LinearAlgebra/Dual.lean`): A linear equivalence between `⨂[R] i, Dual R (M i)` and `Dual R (⨂[R] i, M i)` when all `M i` are finite free modules. If `f : (i : ι) → Dual R (M i)`, then this equivalence sends `⨂ₜ[R] i, f i` to the composition of `PiTensorProduct.map f` with the natural isomorphism `⨂[R] i, R ≃ R` given by multiplication. - [ ] depends on: #11155 (currently used as the base branch; do not merge without switching it back to `master`!) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import new-contributor t-algebra merge-conflict please-adopt blocked-by-other-PR label:t-algebra$	166/2	Mathlib/LinearAlgebra/DirectSum/Finsupp.lean,Mathlib/LinearAlgebra/Dual.lean,Mathlib/LinearAlgebra/TensorProduct/Basis.lean	3	4	['eric-wieser', 'github-actions', 'leanprover-community-mathlib4-bot']	nobody	339-66369 11 months ago	384-81997 1 year ago	0-0 0 seconds
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	new-contributor t-combinatorics merge-conflict blocked-by-other-PR	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', 'leanprover-community-mathlib4-bot']	YaelDillies assignee:YaelDillies	322-68636 10 months ago	322-68636 10 months ago	0-1791 29 minutes
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/)	large-import new-contributor t-topology merge-conflict awaiting-author blocked-by-other-PR	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	298-30872 9 months ago	298-30872 9 months ago	39-21495 39 days
14060	YnirPaz author:YnirPaz	feat(SetTheory/Ordinal/Clubs): define club sets and prove basic properties	Create a file where club sets are defined and their basic properties are proven. I also created a new recursion principle for ordinals, bounded recursion. --- - [ ] depends on: #19189 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-logic merge-conflict blocked-by-other-PR	315/3	Mathlib.lean,Mathlib/Order/SuccPred/Limit.lean,Mathlib/SetTheory/Cardinal/Cofinality.lean,Mathlib/SetTheory/Ordinal/Arithmetic.lean,Mathlib/SetTheory/Ordinal/Club.lean,Mathlib/SetTheory/Ordinal/Topology.lean	6	93	['YaelDillies', 'YnirPaz', 'alreadydone', 'dupuisf', 'github-actions', 'mathlib4-dependent-issues-bot', 'vihdzp', 'zeramorphic']	nobody	276-15993 9 months ago	276-15993 9 months ago	92-44198 92 days
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/)	awaiting-zulip t-computability new-contributor merge-conflict blocked-by-other-PR	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	213-35161 6 months ago	213-35166 6 months ago	0-179 2 minutes
25486	VTrelat author:VTrelat	feat(SetTheory/ZFC/Integers): define integers in ZFC	Extend the model of ZFC with integers following the converse direction as for naturals. We first define a type and then build a set. We finally show that both representations have coercions in both direction: - define a proper type `ZFInt` representing integers based on `ZFNat × ZFNat` and following the usual construction of integers - add theorems on usual algebraic properties of integers - define a set `Int` and show that it matches-i.e. that it is isomorphic to-the type `ZFInt` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) - [ ] depends on: #25483 - [ ] depends on: #25485	t-set-theory new-contributor merge-conflict blocked-by-other-PR	2003/0	Mathlib/Data/Set/Prod.lean,Mathlib/SetTheory/ZFC/Basic.lean,Mathlib/SetTheory/ZFC/Booleans.lean,Mathlib/SetTheory/ZFC/Integers.lean	4	3	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	122-79113 4 months ago	122-79113 4 months ago	0-2067 34 minutes
25484	VTrelat author:VTrelat	feat(SetTheory/ZFC/Booleans): define Boolean algebra in ZFC	Extend the model of ZFC with Boolean algebra: - define a set 𝔹 of booleans - define a proper type `ZFBool` representing booleans - add theorems on usual algebraic properties of booleans - provide usual boolean notations like `⊤`, `⊥`, `∧`, `∨`, etc. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) - [ ] depends on: #25483	t-set-theory new-contributor merge-conflict blocked-by-other-PR	619/0	Mathlib/Data/Set/Prod.lean,Mathlib/SetTheory/ZFC/Basic.lean,Mathlib/SetTheory/ZFC/Booleans.lean	3	3	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	122-79104 4 months ago	122-79104 4 months ago	0-1523 25 minutes
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	new-contributor t-logic merge-conflict awaiting-author blocked-by-other-PR	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	108-9737 3 months ago	108-9738 3 months ago	0-35689 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/)	new-contributor t-algebra merge-conflict blocked-by-other-PR 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	105-46245 3 months ago	105-46246 3 months ago	43-26015 43 days
25488	VTrelat author:VTrelat	feat(SetTheory/ZFC/Rationals): define rationals in ZFC	Extend the model of ZFC with rationals: we define a proper type `ZFRat` representing integers based on pairs of `ZFInt` (enforcing the res to be nonzero) and following the usual construction of rationals. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) - [ ] depends on: #25483 - [ ] depends on: #25485 - [ ] depends on: #25486	t-set-theory new-contributor merge-conflict blocked-by-other-PR	2070/0	Mathlib/Data/Set/Prod.lean,Mathlib/SetTheory/ZFC/Basic.lean,Mathlib/SetTheory/ZFC/Booleans.lean,Mathlib/SetTheory/ZFC/Integers.lean,Mathlib/SetTheory/ZFC/Rationals.lean	5	3	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	104-10863 3 months ago	104-10863 3 months ago	0-1808 30 minutes
26413	michaellee94 author:michaellee94	feat(Analysis/ODE/MaximalSolution): Existence of maximal solutions for ODE 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 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-analysis merge-conflict awaiting-author blocked-by-other-PR	746/1	Mathlib.lean,Mathlib/Analysis/ODE/MaximalSolution.lean,docs/undergrad.yaml	3	13	['github-actions', 'grunweg', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'winstonyin']	nobody	95-42648 3 months ago	95-42649 3 months ago	0-5139 1 hour
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/)	new-contributor merge-conflict blocked-by-other-PR	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	55-59599 1 month ago	78-76012 2 months ago	0-396 6 minutes
28152	Sebi-Kumar author:Sebi-Kumar	feat(AlgebraicTopology): characterize simply connectedness in terms of loops	Show that a space is simply connected if and only if all loops within that space are homotopic to the constant loop. To be used in a proof that the `n`-sphere is simply connected for `n > 1`. --- This code was written at the University of Western Ontario as a part of the Fields Undergraduate Summer Research Program under the supervision of Chris Kapulkin and Daniel Carranza. - [ ] depends on: #28126 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebraic-topology new-contributor merge-conflict blocked-by-other-PR	37/5	Mathlib/AlgebraicTopology/FundamentalGroupoid/Basic.lean,Mathlib/AlgebraicTopology/FundamentalGroupoid/SimplyConnected.lean	2	3	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	47-48715 1 month ago	47-48715 1 month ago	0-2854 47 minutes
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 SetTheory 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. - [ ] depends on: #28208 - [ ] depends on: #28198 - [ ] depends on: #28185 - [ ] depends on: #28152 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebraic-topology new-contributor merge-conflict blocked-by-other-PR	639/6	Mathlib.lean,Mathlib/AlgebraicTopology/FundamentalGroupoid/Basic.lean,Mathlib/AlgebraicTopology/FundamentalGroupoid/SimplyConnected.lean,Mathlib/AlgebraicTopology/FundamentalGroupoid/SimplyConnectedSphere.lean,Mathlib/Analysis/InnerProductSpace/PiL2.lean,Mathlib/Tactic/Linter/DirectoryDependency.lean,Mathlib/Topology/FoldTrans.lean,Mathlib/Topology/Path.lean,Mathlib/Topology/Subpath.lean	9	3	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	47-48713 1 month ago	47-48714 1 month ago	0-23 23 seconds
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/)	new-contributor merge-conflict blocked-by-other-PR	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	37-75765 1 month ago	37-75766 1 month ago	0-340 5 minutes
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/)	large-import new-contributor merge-conflict blocked-by-other-PR	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	22-18075 22 days ago	22-18076 22 days ago	0-241 4 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/)	large-import new-contributor merge-conflict blocked-by-other-PR	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	22-18074 22 days ago	22-18075 22 days ago	0-1234 20 minutes
27953	CoolRmal author:CoolRmal	feat(ProbabilityTheory): Conditional Jensen's Inequality	This PR adds conditional Jensen's inequality. --- - [ ] depends on: #31180 - [ ] depends on: #31411 - [ ] depends on: #31399 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-measure-probability merge-conflict blocked-by-other-PR	462/10	Mathlib.lean,Mathlib/Analysis/LocallyConvex/Separation.lean,Mathlib/MeasureTheory/Function/ConditionalExpectation/Basic.lean,Mathlib/MeasureTheory/Function/ConditionalExpectation/CondJensen.lean,Mathlib/MeasureTheory/MeasurableSpace/Constructions.lean	5	8	['CoolRmal', 'EtienneC30', 'github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	sgouezel assignee:sgouezel	19-59868 19 days ago	19-59869 19 days ago	27-80190 27 days
26160	oliver-butterley author:oliver-butterley	feat(MeasureTheory.VectorMeasure): add several lemmas which characterize variation	Add the following lemmas concerning variation of a VectorMeasure: * `norm_measure_le_variation`: `‖μ E‖ₑ ≤ variation μ E`. * `variation_neg`: `(-μ).variation = μ.variation`. * `variation_zero`: `(0 : VectorMeasure X V).variation = 0`. * `absolutelyContinuous` Co-authored-by: @yoh-tanimoto - [ ] depends on: #26156 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-measure-probability merge-conflict blocked-by-other-PR	432/0	Mathlib.lean,Mathlib/MeasureTheory/VectorMeasure/Variation/Defs.lean,Mathlib/MeasureTheory/VectorMeasure/Variation/Lemmas.lean	3	3	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	16-1560 16 days ago	16-1561 16 days ago	15-68781 15 days
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/)	new-contributor t-measure-probability merge-conflict blocked-by-other-PR	467/0	Mathlib.lean,Mathlib/MeasureTheory/VectorMeasure/Variation/Defs.lean,Mathlib/MeasureTheory/VectorMeasure/Variation/Lemmas.lean	3	3	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	16-1559 16 days ago	16-1560 16 days ago	15-66224 15 days
27378	peakpoint author:peakpoint	refactor(Geometry/Euclidean/Projection): redefine projection and reflection for affine subspaces	This PR continues the work from #25578. Original PR: https://github.com/leanprover-community/mathlib4/pull/25578 - [ ] depends on: #31395	new-contributor t-euclidean-geometry merge-conflict blocked-by-other-PR	316/321	Mathlib/Analysis/Normed/Affine/Isometry.lean,Mathlib/Geometry/Euclidean/Circumcenter.lean,Mathlib/Geometry/Euclidean/Projection.lean	3	10	['github-actions', 'jsm28', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'peakpoint']	nobody	16-1209 16 days ago	16-1210 16 days ago	15-31228 15 days
28208	Sebi-Kumar author:Sebi-Kumar	feat(Topology): add the definition `foldTrans` to concatenate finite sequences of paths	Add `foldTrans`, which folds the function `Path.trans` across a sequence of paths with compatible endpoints, corresponding to the concatenation of a finite sequence of paths. This is implemented with `Fin.dfoldl` from the Batteries library. Prove basic properties about `foldTrans` (i.e., how it behaves with respect to `Path.refl`, `Path.subpath`, and homotopies). --- To provide additional context, I am new to contributing to Mathlib, and I am doing so 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. My goal is to prove that the `n`-sphere is simply connected for `n > 1`, following the proof from Hatcher's "Algebraic Topology." - [ ] depends on: #27261 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-topology merge-conflict blocked-by-other-PR	259/0	Mathlib.lean,Mathlib/Topology/FoldTrans.lean,Mathlib/Topology/Subpath.lean	3	3	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	16-1055 16 days ago	16-1056 16 days ago	0-2340 39 minutes
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	new-contributor t-combinatorics merge-conflict blocked-by-other-PR	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	16-1043 16 days ago	16-1043 16 days ago	0-591 9 minutes
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/)	new-contributor t-measure-probability merge-conflict blocked-by-other-PR	680/0	Mathlib.lean,Mathlib/MeasureTheory/VectorMeasure/Variation/Defs.lean,Mathlib/MeasureTheory/VectorMeasure/Variation/Equiv.lean,Mathlib/MeasureTheory/VectorMeasure/Variation/Lemmas.lean	4	3	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	15-60000 15 days ago	16-1559 16 days ago	15-65390 15 days
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	new-contributor t-category-theory merge-conflict awaiting-author blocked-by-other-PR	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	15-59621 15 days ago	16-1036 16 days ago	0-24930 6 hours
31411	CoolRmal author:CoolRmal	feat: a convex lower-semicontinuous function is the supremum of a sequence of affine functions in a separable space	This lemma is needed in the proof of conditional Jensen's inequality: #27953 The lemmas in this PR need the RCLike API, so it is not suitable to put them in Mathlib.Topology.Semicontinuous or Mathlib.Analysis.Convex.Function as they does not import RCLike. I tried to put these lemmas in a RCLike related file but I encountered warnings about import (e.g. Modules starting with Mathlib.Topology are not allowed to import modules starting with ...). Therefore, I temporarily put them in [Mathlib/MeasureTheory/Function/ConditionalExpectation/CondJensen.lean](https://github.com/leanprover-community/mathlib4/pull/31411/files#diff-930cc0818908e1ab51f74f3729ae6de8ed43f7914e94ca07c619f48a4c49aa9c). --- - [ ] depends on: #31180 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-analysis merge-conflict blocked-by-other-PR	337/10	Mathlib.lean,Mathlib/Analysis/LocallyConvex/Separation.lean,Mathlib/MeasureTheory/Function/ConditionalExpectation/Basic.lean,Mathlib/MeasureTheory/Function/ConditionalExpectation/CondJensen.lean	4	3	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	15-59559 15 days ago	15-81683 15 days ago	0-129 2 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/)	new-contributor t-analysis awaiting-author blocked-by-other-PR WIP	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	4	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	faenuccio assignee:faenuccio	12-81728 12 days ago	12-81896 12 days ago	0-634 10 minutes
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/)	new-contributor t-combinatorics blocked-by-other-PR	302/0	Mathlib.lean,Mathlib/Combinatorics/Enumerative/Polya.lean	2	3	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	b-mehta assignee:b-mehta	8-68916 8 days ago	8-69629 8 days ago	22-58765 22 days
30881	FlAmmmmING author:FlAmmmmING	feat(RingTheory/PowerSeries/Schroder.lean): Define the generating function for large and small Schroder number	Define the generating function for large and small Schroder number. Main result : Prove some lemmas and the generating function of large Schroder. Todo : Prove the generating function of small Schroder. --- - [ ] depends on: #30609 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor blocked-by-other-PR	352/1	Mathlib.lean,Mathlib/Combinatorics/Enumerative/Catalan.lean,Mathlib/RingTheory/PowerSeries/Schroder.lean	3	3	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	dwrensha assignee:dwrensha	8-68894 8 days ago	8-70424 8 days ago	31-71873 31 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
23213	mattrobball author:mattrobball	chore(RingTheory.Derivation): add a `LinearMapClass` instance	Often we want `simp` to call `map_zero` or `map_add` for a `Derivation`. To find the `ZeroHomClass` or `AddHomClass` instance necessary it starts to climb up the type class hierarchy including looking for a `LinearMapClass` instance which didn't exist. Consequently, sythesis would look in a lot of crazy places trying to summon ring structures on the module or on derivations itself. Here we add the missing `LinearMapClass` instance so that `simp` is more efficient. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra delegated label:t-algebra$	5/3	Mathlib/RingTheory/Derivation/Basic.lean	1	8	['github-actions', 'j-loreaux', 'leanprover-bot', 'mathlib-bors', 'mattrobball']	nobody	210-35859 6 months ago	210-35859 6 months ago	47-39026 47 days
23214	mattrobball author:mattrobball	perf(Module.LinearMap.Defs): deprioritize projections to parents for `SemilinearMapClass`	Trying to figure out if a given type has a `SemilinearMapClass` instance when all we want is an `AddHomClass` or a `MulActionSemiHomClass` can be quite expensive since there are multiple ways to crawl the algebraic hierarchy to generate `LinearMapClass` instances. If these fail, then they fail slowly. We deprioritize the projections from `SemilinearMapClass` to `AddHomClass` and `MulActionSemiHomClass` to make this one of the last choices. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra delegated label:t-algebra$	6/0	Mathlib/Algebra/Module/LinearMap/Defs.lean	1	6	['github-actions', 'j-loreaux', 'leanprover-bot', 'mathlib-bors', 'mattrobball']	nobody	210-35625 6 months ago	210-35625 6 months ago	47-32152 47 days
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	182-69648 5 months ago	182-70538 5 months ago	0-11212 3 hours
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 easy delegated	17/7	Mathlib/Combinatorics/Enumerative/Composition.lean,Mathlib/Data/Finset/Sort.lean	2	4	['eric-wieser', 'github-actions', 'mathlib-bors', 'ocfnash']	nobody	49-45752 1 month ago	70-77842 2 months ago	3-79002 3 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 t-category-theory delegated	182/2	Mathlib/AlgebraicTopology/SimplexCategory/GeneratorsRelations/NormalForms.lean	1	6	['github-actions', 'joelriou', 'mathlib-bors', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	44-65422 1 month ago	45-57138 1 month ago	0-22513 6 hours
30914	eric-wieser author:eric-wieser	feat(Data/Set/NAry): lemmas for `diff`	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data t-order delegated	10/0	Mathlib/Data/Set/NAry.lean	1	2	['github-actions', 'grunweg', 'mathlib-bors']	nobody	39-55510 1 month ago	39-55510 1 month ago	0-56942 15 hours
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/)	t-data delegated	5/0	Mathlib/Data/Int/ModEq.lean	1	3	['fpvandoorn', 'github-actions', 'mathlib-bors']	nobody	20-77343 20 days ago	174-63623 5 months ago	1-19951 1 day
31607	grunweg author:grunweg	chore: rename `continuous{,On,At,Within}_const to `ContinuousFoo.const`	Needs fixing all remaining deprecation warnings. Zulip discussion: [#mathlib4 > Naming convention @ 💬](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Naming.20convention/near/447491526) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-CI delegated	86/82	Archive/Hairer.lean,Mathlib/Analysis/BoxIntegral/Box/Basic.lean,Mathlib/Analysis/CStarAlgebra/ContinuousFunctionalCalculus/Unital.lean,Mathlib/Analysis/Calculus/Deriv/MeanValue.lean,Mathlib/Analysis/Calculus/DiffContOnCl.lean,Mathlib/Analysis/Calculus/MeanValue.lean,Mathlib/Analysis/Calculus/Taylor.lean,Mathlib/Analysis/Complex/AbsMax.lean,Mathlib/Analysis/Complex/CauchyIntegral.lean,Mathlib/Analysis/Complex/PhragmenLindelof.lean,Mathlib/Analysis/Complex/RemovableSingularity.lean,Mathlib/Analysis/Convex/Exposed.lean,Mathlib/Analysis/Convex/Gauge.lean,Mathlib/Analysis/Convex/PartitionOfUnity.lean,Mathlib/Analysis/Convolution.lean,Mathlib/Analysis/Normed/Module/Ball/Homeomorph.lean,Mathlib/Analysis/Normed/Operator/BoundedLinearMaps.lean,Mathlib/Analysis/ODE/PicardLindelof.lean,Mathlib/Analysis/SpecialFunctions/Gamma/Basic.lean,Mathlib/Analysis/SpecialFunctions/Integrability/Basic.lean,Mathlib/Analysis/SpecialFunctions/Pow/Continuity.lean,Mathlib/MeasureTheory/Integral/Bochner/Basic.lean,Mathlib/MeasureTheory/Integral/CircleIntegral.lean,Mathlib/MeasureTheory/Integral/CircleTransform.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral/Basic.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral/FundThmCalculus.lean,Mathlib/MeasureTheory/Integral/RieszMarkovKakutani/Real.lean,Mathlib/NumberTheory/LSeries/PrimesInAP.lean,Mathlib/NumberTheory/NumberField/CanonicalEmbedding/NormLeOne.lean,Mathlib/Topology/Algebra/ContinuousMonoidHom.lean,Mathlib/Topology/Algebra/GroupWithZero.lean,Mathlib/Topology/Algebra/Indicator.lean,Mathlib/Topology/Algebra/Order/Floor.lean,Mathlib/Topology/Connected/Basic.lean,Mathlib/Topology/Constructions.lean,Mathlib/Topology/Constructions/SumProd.lean,Mathlib/Topology/Continuous.lean,Mathlib/Topology/ContinuousOn.lean,Mathlib/Topology/FiberBundle/Basic.lean,Mathlib/Topology/Hom/ContinuousEval.lean,Mathlib/Topology/Homeomorph/Defs.lean,Mathlib/Topology/Order.lean,Mathlib/Topology/Order/IntermediateValue.lean,Mathlib/Topology/VectorBundle/Basic.lean	44	3	['github-actions', 'j-loreaux', 'mathlib-bors']	nobody	20-1847 20 days ago	20-12869 20 days ago	0-1 1 second
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 label:t-algebra$	16/7	Mathlib/Algebra/Group/Units/Hom.lean,Mathlib/AlgebraicGeometry/Scheme.lean,Mathlib/Geometry/RingedSpace/LocallyRingedSpace.lean,Mathlib/Geometry/RingedSpace/LocallyRingedSpace/HasColimits.lean,Mathlib/Geometry/RingedSpace/OpenImmersion.lean	5	12	['adomani', 'alreadydone', 'erdOne', 'eric-wieser', 'github-actions', 'jcommelin', 'leanprover-community-bot-assistant', 'mathlib-bors']	mattrobball assignee:mattrobball	16-83310 16 days ago	16-83310 16 days ago	24-84527 24 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 delegated	119/4	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	18	['adomani', 'b-mehta', 'eric-wieser', 'github-actions', 'grunweg', 'kim-em', 'mathlib-bors', 'mathlib4-merge-conflict-bot']	nobody	14-41141 14 days ago	14-41158 14 days ago	15-14325 15 days
31525	kim-em author:kim-em	feat: convex combinations in `Set.Icc`	This will hopefully become obsolete with a more general theory of convex spaces, but this would be helpful to go on for now. Note: Proofs in this PR were developed with assistance from Claude.	t-topology delegated	142/0	Mathlib/Topology/UnitInterval.lean	1	5	['github-actions', 'jcommelin', 'kim-em', 'mathlib-bors']	ADedecker assignee:ADedecker	12-20283 12 days ago	13-77037 13 days ago	8-54621 8 days
31929	kim-em author:kim-em	feat: replace `Finsupp.embDomain_apply` with more general lemma	- [ ] depends on #31927 - [ ] depends on #31928	delegated	24/22	Mathlib/Algebra/BigOperators/Finsupp/Basic.lean,Mathlib/Algebra/Polynomial/Reverse.lean,Mathlib/Analysis/Fourier/BoundedContinuousFunctionChar.lean,Mathlib/Data/Finsupp/Basic.lean,Mathlib/Data/Finsupp/Defs.lean,Mathlib/Data/Finsupp/Option.lean,Mathlib/Data/Finsupp/Sigma.lean,Mathlib/Data/Finsupp/Single.lean,Mathlib/Data/List/ToFinsupp.lean	9	5	['eric-wieser', 'github-actions', 'jcommelin', 'mathlib-bors', 'mathlib4-merge-conflict-bot']	nobody	7-13342 7 days ago	7-13425 7 days ago	2-51105 2 days
31455	kim-em author:kim-em	feat: products of locally contractible spaces	--- - [x] depends on: #31453 - [x] depends on: #31454 Note: Proofs in this PR were developed with assistance from Claude.	t-topology delegated	31/10	Mathlib/Topology/Homotopy/LocallyContractible.lean	1	7	['github-actions', 'j-loreaux', 'mathlib-bors', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'urkud']	dagurtomas assignee:dagurtomas	7-1116 7 days ago	9-6271 9 days ago	9-58985 9 days
31444	harahu author:harahu	doc(Probability/Martingale/BorelCantelli): polish docstrings	Fix some typos and inconsistencies in `BorelCantelli`. The issues were found and fixed using Codex. The most substantive change is going from $$f_n := \sum_{k < n} \mathbf{1}_{s_{n + 1}} - \mathbb{P}[s_{n + 1} \mid \mathcal{F}_n]$$ to $$f_n := \sum_{k < n} \big(\mathbf{1}_{s_{k + 1}} - \mathbb{P}[s_{k + 1} \mid \mathcal{F}_k]\big).$$ As far as I can tell, this is more faithful to the contents of the file. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-measure-probability delegated	5/5	Mathlib/Probability/Martingale/BorelCantelli.lean	1	4	['github-actions', 'grunweg', 'harahu', 'mathlib-bors']	nobody	4-62840 4 days ago	24-64780 24 days ago	0-71658 19 hours
31165	AntoineChambert-Loir author:AntoineChambert-Loir	feat(LinearAlgebra/Transvection): base change of transvections	The base change of a transvection of a module. --- - [x] depends on: #31162 - [x] depends on: #31240 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import t-algebra delegated label:t-algebra$	60/16	Mathlib/LinearAlgebra/Charpoly/BaseChange.lean,Mathlib/LinearAlgebra/TensorProduct/Tower.lean,Mathlib/LinearAlgebra/Transvection.lean,Mathlib/RingTheory/TensorProduct/IsBaseChangeHom.lean	4	13	['github-actions', 'mathlib-bors', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'ocfnash']	ocfnash assignee:ocfnash	1-64362 1 day ago	1-64362 1 day ago	1-5284 1 day
14712	FR-vdash-bot author:FR-vdash-bot	perf: change instance priority and order about `OfNat`	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	slow-typeclass-synthesis t-algebra merge-conflict delegated label:t-algebra$	49/20	Mathlib/Algebra/Group/Nat.lean,Mathlib/Algebra/Group/ZeroOne.lean,Mathlib/Algebra/Homology/Embedding/Basic.lean,Mathlib/Algebra/Tropical/Basic.lean,Mathlib/Data/BitVec.lean,Mathlib/Data/Nat/Cast/Defs.lean,Mathlib/Data/Rat/Defs.lean,Mathlib/Data/UInt.lean,Mathlib/NumberTheory/ArithmeticFunction.lean	9	24	['FR-vdash-bot', 'MichaelStollBayreuth', 'eric-wieser', 'github-actions', 'j-loreaux', 'leanprover-bot', 'mathlib-bors']	nobody	424-77655 1 year ago	427-14731 1 year ago	20-15089 20 days
19275	eric-wieser author:eric-wieser	fix: if nolint files change, do a full rebuild	Otherwise CI will succeed when removing entries from the file, but fail later when someone changes something unrelated. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict delegated	8/0	lakefile.lean	1	20	['YaelDillies', 'adomani', 'eric-wieser', 'github-actions', 'grunweg', 'mathlib-bors']	nobody	244-63999 8 months ago	244-63999 8 months ago	0-214 3 minutes
17129	joneugster author:joneugster	feat(Tactic/Linter): add unicode linter for unicode variant-selectors	Unicode characters can be followed by one of the two "variant-selectors" `\FE0E` (text) or `\FE0F` (emoji). These appear to the user as a single unicode character and they might copy them by accident. For example `✅️` (`\u2705\uFE0F`), `✅` (`\u2705`) and `✅︎` (`\u2705\uFE0E`) are three variants of the "same" unicode character. The one without variant-selector might display as either emoji or not, depending on the user's device and font. Add unicode linter ensuring variant-selector only appear on specified characters and also ensuring these characters always have the correct variant selector to avoid confusions. Everything flagged by this linter can be fixed fully automatically with `lake exe lint-style --fix` or by commenting `bot fix style` on the PR. --- - tracking PR: #16215 ## Zulip discussions: - https://leanprover.zulipchat.com/#narrow/stream/287929-mathlib4/topic/Whitelist.20for.20Unicode.3F - https://leanprover.zulipchat.com/#narrow/stream/113488-general/topic/Lean.20specific.20font ## Related PRs: - leanprover/lean4#5015 added some emoji-variant selectors to Emojis used in `Lean` itself. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import t-linter merge-conflict delegated awaiting-author	245/14	Mathlib.lean,Mathlib/GroupTheory/GroupExtension/Defs.lean,Mathlib/Tactic.lean,Mathlib/Tactic/Linter/TextBased.lean,Mathlib/Tactic/Linter/UnicodeLinter.lean,Mathlib/Tactic/Widget/Calc.lean,Mathlib/Tactic/Widget/CongrM.lean,Mathlib/Tactic/Widget/Conv.lean,Mathlib/Tactic/Widget/GCongr.lean,Mathlib/Topology/ContinuousMap/Weierstrass.lean,MathlibTest/LintStyleTextBased.lean	11	25	['YaelDillies', 'adomani', 'github-actions', 'grunweg', 'joneugster', 'kim-em', 'leanprover-community-bot-assistant']	nobody	202-58021 6 months ago	202-58023 6 months ago	82-54712 82 days
13483	adomani author:adomani	feat: automatically replace deprecations	This PR introduces `lake exe update_deprecations` that uses the cache to automatically replace deprecated declarations with the corresponding un-deprecated one. The script handles namespacing, replacing a possibly non-fully-qualified, deprecated name with the fully-qualified non-deprecated name. It is also possible to use ```bash lake exe update_deprecations --mods One.Two.Three,Dd.Ee.Ff ``` to limit the scope of the replacements to the modules `One.Two.Three` and `Dd.Ee.Ff`. This is intended to be a first step in automating updates: combining this with a linter that emits appropriate warnings, the functionality of `lake exe update_deprecations` can be extended to perform more complicated updates. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-meta merge-conflict delegated awaiting-author	306/0	Mathlib.lean,Mathlib/Tactic.lean,Mathlib/Tactic/UpdateDeprecations.lean,MathlibTest/UpdateDeprecations.lean,lakefile.lean,scripts/README.md,scripts/update_deprecations.lean	7	16	['YaelDillies', 'adomani', 'github-actions', 'j-loreaux', 'jcommelin', 'leanprover-community-bot-assistant', 'mathlib-bors', 'sgouezel']	joneugster assignee:joneugster	177-24910 5 months ago	177-24911 5 months ago	34-82472 34 days
17627	hrmacbeth author:hrmacbeth	feat: universal properties of vector bundle constructions	Characterizations for the smoothness of maps into the total spaces of (1) the direct sum of two vector bundles; (2) the pullback of a vector bundle. This gap in the library was exposed by #17358. --- - [x] depends on: #22804 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-differential-geometry merge-conflict delegated	311/9	Mathlib/Data/Bundle.lean,Mathlib/Geometry/Manifold/VectorBundle/Basic.lean,Mathlib/Geometry/Manifold/VectorBundle/Pullback.lean,Mathlib/Topology/FiberBundle/Constructions.lean	4	24	['PatrickMassot', 'github-actions', 'grunweg', 'hrmacbeth', 'j-loreaux', 'leanprover-community-bot-assistant', 'mathlib-bors', 'mathlib4-dependent-issues-bot', 'sgouezel']	grunweg assignee:grunweg	153-15509 5 months ago	153-15509 5 months ago	91-73632 91 days
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 - `mul_left_monotone` and `mul_right_monotone` are exactly the wrong way around - `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/)	merge-conflict delegated	238/171	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/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/PSeries.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/Chunk.lean,Mathlib/Combinatorics/SimpleGraph/Regularity/Lemma.lean,Mathlib/Computability/Ackermann.lean,Mathlib/Data/ENNReal/Inv.lean,Mathlib/Data/ENNReal/Operations.lean,Mathlib/Data/Nat/Choose/Factorization.lean,Mathlib/Data/Real/Pi/Bounds.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/Padics/Hensel.lean,Mathlib/Order/Concept.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/Different.lean,Mathlib/RingTheory/DedekindDomain/Ideal.lean,Mathlib/RingTheory/FractionalIdeal/Basic.lean,Mathlib/RingTheory/FractionalIdeal/Operations.lean,Mathlib/Topology/EMetricSpace/Lipschitz.lean,Mathlib/Topology/MetricSpace/Antilipschitz.lean,Mathlib/Topology/MetricSpace/Holder.lean	59	8	['JovanGerb', 'bryangingechen', 'github-actions', 'leanprover-community-bot-assistant', 'linesthatinterlace', 'mathlib-bors']	bryangingechen assignee:bryangingechen	146-23224 4 months ago	146-52248 4 months ago	2-60107 2 days
27872	JovanGerb author:JovanGerb	chore(gcongr): clean up imports	This PR removes redundant `gcongr` imports. And when we do import `gcongr`, we now also import the core `@[gcongr]` tags, and also `grw`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import merge-conflict delegated	7/23	Archive/Imo/Imo2019Q4.lean,Mathlib/Algebra/ContinuedFractions/Computation/ApproximationCorollaries.lean,Mathlib/Algebra/ContinuedFractions/Computation/Approximations.lean,Mathlib/Algebra/MvPolynomial/SchwartzZippel.lean,Mathlib/Algebra/Order/BigOperators/Expect.lean,Mathlib/Algebra/Order/CauSeq/Basic.lean,Mathlib/Algebra/Order/Chebyshev.lean,Mathlib/Analysis/Convex/Segment.lean,Mathlib/Analysis/Convex/Star.lean,Mathlib/Combinatorics/Additive/PluenneckeRuzsa.lean,Mathlib/Combinatorics/Enumerative/Catalan.lean,Mathlib/Combinatorics/SetFamily/FourFunctions.lean,Mathlib/Combinatorics/SimpleGraph/Density.lean,Mathlib/Combinatorics/SimpleGraph/Triangle/Basic.lean,Mathlib/Data/Nat/Basic.lean,Mathlib/NumberTheory/FLT/Polynomial.lean,Mathlib/NumberTheory/FermatPsp.lean,Mathlib/Order/Basic.lean,Mathlib/Order/Filter/AtTopBot/Archimedean.lean,Mathlib/Tactic/GCongr/CoreAttrs.lean,Mathlib/Topology/EMetricSpace/Paracompact.lean	21	11	['JovanGerb', 'bryangingechen', 'github-actions', 'grunweg', 'mathlib-bors', 'mathlib4-merge-conflict-bot']	nobody	106-11245 3 months ago	106-11245 3 months ago	4-34325 4 days
23600	mattrobball author:mattrobball	perf(Quiver.Basic): make `IsThin` a `class`	It seems problematic that `Quiver.IsThin` is an `abbrev` for (essentially) `Subsingleton`. We turn it in a one-field class. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict delegated	27/21	Mathlib/CategoryTheory/Bicategory/Coherence.lean,Mathlib/CategoryTheory/Category/Preorder.lean,Mathlib/CategoryTheory/Generator/Basic.lean,Mathlib/CategoryTheory/Groupoid/Basic.lean,Mathlib/CategoryTheory/Limits/Shapes/WidePullbacks.lean,Mathlib/CategoryTheory/Limits/SmallComplete.lean,Mathlib/CategoryTheory/Monoidal/Free/Coherence.lean,Mathlib/CategoryTheory/Skeletal.lean,Mathlib/CategoryTheory/Subobject/MonoOver.lean,Mathlib/CategoryTheory/Thin.lean,Mathlib/Combinatorics/Quiver/Basic.lean	11	17	['b-mehta', 'github-actions', 'leanprover-bot', 'mathlib-bors', 'mathlib4-merge-conflict-bot', 'mattrobball']	nobody	38-55096 1 month ago	38-55097 1 month ago	0-5717 1 hour
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/)	t-algebra merge-conflict 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	34-67341 1 month ago	34-67342 1 month ago	28-12053 28 days
25481	kbuzzard author:kbuzzard	chore: refactor Algebra.TensorProduct.rightAlgebra	The declaration `Algebra.TensorProduct.rightAlgebra` makes `A ⊗[R] B` into a `B`-algebra (here `R` is a `CommSemiring`, `A` is a `Semiring` and an `R`-algebra, and `B` is a `CommSemiring` and an `R`-algebra). It is not an instance because if A = B it causes a diamond. However in the many cases where A isn't B, it can occasionally be useful. However one could imagine that in the many cases where an R-module `M` also isn't `B`, it might occasionally be useful to make `M ⊗[R] B` into a `B`-module (and indeed I am finding this in FLT). With the current definition of `Algebra.TensorProduct.rightAlgebra` this is difficult to do without causing diamonds in the case when `M` happens to be an `R`-algebra (by which I mean "I failed to do this in finite time"). One fix for this is just to redefine `Algebra.TensorProduct.rightAlgebra` so that the `smul` field is ``` smul b ab := TensorProduct.comm _ _ _ (b • (TensorProduct.comm _ _ _ ab)) ``` i.e. literally "swap the product around, use mathlib's instance making `B ⊗[R] A` into a `B`-algebra, and then swap back". Then the same definition can be used to make `M ⊗[R] B` into a `B`-module and on the odd occasion where this point of view is useful, there is no diamond. This is what we do in this PR. After adding one simp lemma there is no breakage at all in mathlib. Furthermore, for those who have observed that we want to build on this algebra instance sometimes and, for example, add instances of the form "if M is finite over R then M ⊗[R] B is finite over B" -- these instances are really easy to add now with this new definition, because you simply pull back the analogous finite left module instance along the isomorphism M ⊗[R] B = B ⊗[R] M. Examples (from FLT, where the right action is put in a scope): ``` scoped instance [Module.Finite R M] : Module.Finite A (M ⊗[R] A) := Module.Finite.equiv (Module.TensorProduct.comm R A M) scoped instance [Module.Free R M] : Module.Free A (M ⊗[R] A) := Module.Free.of_equiv (Module.TensorProduct.comm R A M) ``` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict delegated label:t-algebra$	33/6	Mathlib/RingTheory/TensorProduct/Basic.lean	1	8	['adomani', 'github-actions', 'kbuzzard', 'leanprover-bot', 'mathlib-bors', 'mathlib4-merge-conflict-bot']	adomani assignee:adomani	24-71992 24 days ago	24-71993 24 days ago	56-85445 56 days
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 t-meta merge-conflict delegated awaiting-author	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']	alexjbest assignee:alexjbest	16-1754 16 days ago	16-1755 16 days ago	83-71907 83 days