The mathlib review queue

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This dashboard was last updated on: October 09, 2025 at 18:22 UTC

Review queue

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
25758 YaelDillies
author:YaelDillies
chore: shortcut instance `CompleteLattice α → PartialOrder α` This avoids using the path `CompleteLattice α → CompletePartialOrder α → PartialOrder α` that goes through `Order.CompletePartialOrder` and makes it appear used to our automation, such as `shake` or `#min_imports`. This is a followup to #25358. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-order 7/0 Mathlib/Order/CompleteLattice/Defs.lean 1 6 ['Ruben-VandeVelde', 'eric-wieser', 'github-actions', 'leanprover-bot'] bryangingechen
assignee:bryangingechen
68-62502
2 months ago
99-70242
3 months ago
119-34419
119 days
26054 FMLJohn
author:FMLJohn
feat(RingTheory/GradedAlgebra/Homogeneous/Subsemiring): homogeneous subsemirings of a graded semiring --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) In this pull request, we have defined homogeneous subsemirings of `GradedRing 𝒜` where `𝒜 : ι → σ`, `SetLike σ A` and `AddSubmonoidClass σ A`. ## Main definitions For any `R : Subsemiring A`: * `Subsemiring.IsHomogeneous 𝒜 R`: The property that a subsemiring is closed under `GradedRing.proj`. * `HomogeneousSubsemiring 𝒜`: The structure extending subsemirings which satisfy `Subsemiring.IsHomogeneous`. t-ring-theory 120/0 Mathlib.lean,Mathlib/RingTheory/GradedAlgebra/Homogeneous/Subsemiring.lean 2 1 ['github-actions'] kim-em
assignee:kim-em
65-31422
2 months ago
65-31422
2 months ago
114-134
114 days
24730 YaelDillies
author:YaelDillies
feat(RingTheory): group-like elements Define group-like elements in a bialgebra, ie elements such that `η a = 1` and `Δ a = a ⊗ₜ a`. We prove that group-like elements of a coalgebra over a domain are linearly independent, group-like elements of a bialgebra form a monoid, group-like elements of a Hopf algebra form a group. From Toric Co-authored-by: Michał Mrugała --- - [x] depends on: #24747 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory toric 309/0 Mathlib.lean,Mathlib/RingTheory/Bialgebra/GroupLike.lean,Mathlib/RingTheory/Coalgebra/GroupLike.lean,Mathlib/RingTheory/HopfAlgebra/GroupLike.lean 4 42 ['Julian-Kuelshammer', 'Parcly-Taxel', 'Whysoserioushah', 'YaelDillies', 'erdOne', 'eric-wieser', 'github-actions', 'leanprover-bot', 'mathlib4-dependent-issues-bot', 'smorel394'] eric-wieser
assignee:eric-wieser
65-31316
2 months ago
65-31316
2 months ago
151-74766
151 days
26770 Jun2M
author:Jun2M
feat(Combinatorics/Graph) : subgraph relations and operations 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 703/0 Mathlib.lean,Mathlib/Combinatorics/Graph/Subgraph.lean 2 1 ['github-actions'] awainverse
assignee:awainverse
63-62490
2 months ago
96-73968
3 months ago
96-74004
96 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 13/0 Mathlib/MeasureTheory/PiSystem.lean 1 13 ['EtienneC30', 'KiringYJ', 'github-actions', 'ocfnash'] RemyDegenne
assignee:RemyDegenne
62-62489
2 months ago
70-12138
2 months ago
96-86374
96 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 121/8 Mathlib.lean,Mathlib/Order/CompleteLattice/Defs.lean,Mathlib/Order/LawfulSupInf.lean 3 25 ['PierreQuinton', 'YaelDillies', 'github-actions', 'plp127', 'vihdzp'] YaelDillies
assignee:YaelDillies
62-26266
2 months ago
74-9563
2 months ago
74-9590
74 days
27664 pechersky
author:pechersky
feat(Topology,Analysis): discrete topology metric space and normed groups Explicit construction of the discrete topology metric space and normed groups where `dist x y = 1` for all `x != y` Provide PseudoMetricSpace, MetricSpace, Seminormed(Add)Group, and Normed(Add)Group constructions --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-topology 137/0 Mathlib/Analysis/Normed/Group/Basic.lean,Mathlib/Topology/MetricSpace/Basic.lean,Mathlib/Topology/MetricSpace/Pseudo/Constructions.lean 3 3 ['github-actions', 'kckennylau', 'pechersky'] urkud
assignee:urkud
61-62500
2 months ago
71-52512
2 months ago
71-52498
71 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 509/1 Mathlib.lean,Mathlib/Topology/MetricSpace/BundledFun.lean,Mathlib/Topology/UniformSpace/Ultra/Pseudometrizable.lean 3 8 ['ADedecker', 'fpvandoorn', 'github-actions', 'mathlib4-dependent-issues-bot', 'pechersky'] urkud
assignee:urkud
58-62506
1 month ago
121-49816
3 months ago
136-81743
136 days
27000 gasparattila
author:gasparattila
feat(Analysis/Normed/Group/Quotient): isometric versions of isomorphisms This PR adds an isometric version of the third isomorphism theorem for groups and modules. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) large-import new-contributor t-analysis 49/2 Mathlib/Analysis/Normed/Group/Quotient.lean 1 1 ['github-actions'] urkud
assignee:urkud
58-62501
1 month ago
90-15228
2 months ago
90-15272
90 days
27754 Parcly-Taxel
author:Parcly-Taxel
feat: `finCycle` as iterated `finRotate` Originally used in #25786, but eventually discovered to be unnecessary. t-logic 26/5 Mathlib/Logic/Equiv/Fin/Rotate.lean 1 1 ['github-actions'] fpvandoorn
assignee:fpvandoorn
56-62492
1 month ago
70-10848
2 months ago
70-10894
70 days
27946 plp127
author:plp127
refactor: have `MetrizableSpace` not depend on `MetricSpace` Some theorems for uniform spaces with a countably generated uniformity do not mention their uniformity in any of the hypotheses or the conclusion (for example `UniformSpace.isCompact_iff_isSeqCompact`). This PR allows those theorems to be stated for (pseudo)metrizable spaces without importing the real numbers. See also #2032 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-topology 129/102 Mathlib/Analysis/Fourier/RiemannLebesgueLemma.lean,Mathlib/Topology/Compactness/PseudometrizableLindelof.lean,Mathlib/Topology/GDelta/MetrizableSpace.lean,Mathlib/Topology/Metrizable/Basic.lean,Mathlib/Topology/Metrizable/ContinuousMap.lean,Mathlib/Topology/Metrizable/Real.lean,Mathlib/Topology/Metrizable/Uniformity.lean 7 7 ['github-actions', 'leanprover-bot', 'leanprover-community-mathlib4-bot'] urkud
assignee:urkud
55-62477
1 month ago
65-30762
2 months ago
65-82635
65 days
28141 YaelDillies
author:YaelDillies
chore: deprecate `BialgHom.coe_toLinearMap` `BialgHom.toLinearMap` is a fake projection. From Toric --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory toric easy 5/11 Mathlib/RingTheory/Bialgebra/Hom.lean 1 8 ['YaelDillies', 'eric-wieser', 'github-actions'] alreadydone
assignee:alreadydone
53-62480
1 month ago
61-39609
2 months ago
61-39600
61 days
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 6/0 Mathlib/Analysis/InnerProductSpace/PiL2.lean 1 1 ['github-actions'] urkud
assignee:urkud
52-62481
1 month ago
59-75717
1 month ago
59-75755
59 days
28072 kckennylau
author:kckennylau
feat(RingTheory/Valuation): make tactic rw_val_equiv Co-authored by Aaron Liu and Bhavik Mehta. A tactic to rewrite relations such as `max (v₁ x) (v₁ y) * v₁ z < 1` into `max (v₂ x) (v₂ y) * v₂ z < 1` , given `h : v₁.IsEquiv v₂`. Allowed relations are `≤`, `<`, `=`, `≠`. Allowed operations are: `0`, `1`, `v₁ r`, `⁻¹`, `^` (both `ℕ` and `ℤ`), `*`, `/`, `min`, `max`. Examples: ```lean example {R Γ₁ Γ₂ : Type} [Ring R] [LinearOrderedCommMonoidWithZero Γ₁] [LinearOrderedCommMonoidWithZero Γ₂] {v₁ : Valuation R Γ₁} {v₂ : Valuation R Γ₂} (h : v₁.IsEquiv v₂) {y z : R} : {x | v₁ x ^ 2 * min (v₁ y) (v₁ z) ≤ 1} = {x | v₂ x ^ 2 * min (v₂ y) (v₂ z) ≤ 1} := by rw_val_equiv h ``` It is also possible to use `←` to rewrite in the opposite direction, and to use `at h1 h3 ⊢` to specify which hypotheses (and/or goal) to rewrite, similar to the syntax of `rw`. There is also `rwa_val_equiv` to work like `rwa`. --- Zulip: [#Is there code for X? > Tactics for comparing equivalent valuations](https://leanprover.zulipchat.com/#narrow/channel/217875-Is-there-code-for-X.3F/topic/Tactics.20for.20comparing.20equivalent.20valuations) [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory 455/13 Mathlib/RingTheory/Valuation/Basic.lean,MathlibTest/Simproc/ValEquiv.lean 2 34 ['b-mehta', 'eric-wieser', 'github-actions', 'kckennylau', 'pechersky', 'plp127'] erdOne
assignee:erdOne
51-62496
1 month ago
61-84188
2 months ago
62-58685
62 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 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 1 ['github-actions'] awainverse
assignee:awainverse
50-62504
1 month ago
61-80973
2 months ago
61-81010
61 days
28186 Sebi-Kumar
author:Sebi-Kumar
feat(Topology/Homotopy/Path): Add IsEquiv instance for Path.Homotopic Add `instance : IsEquiv (Path x₀ x₁) Homotopic` to the library. Allow use of lemmas like `of_eq` when proving two paths are homotopic. --- To provide additional context, I am relatively new to contributing to Mathlib, and I am doing so as a part of the Fields Undergraduate Summer Research Program hosted at the University of Western Ontario and supervised by Chris Kapulkin and Daniel Carranza. My goal is to prove that the `n`-sphere is simply connected for `n > 1`. Also, I am not super familiar with `IsEquiv` and when it should/shouldn't be used. I just wanted to use a lemma like `Path.Homotopic.of_eq` at one point while working on my code, and thought this was the best way to add such a result to the library. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-topology 5/0 Mathlib/Topology/Homotopy/Path.lean 1 4 ['Sebi-Kumar', 'github-actions', 'kckennylau'] PatrickMassot
assignee:PatrickMassot
50-62501
1 month ago
60-7431
1 month ago
60-7471
60 days
28399 Ruben-VandeVelde
author:Ruben-VandeVelde
feat: ring-theoretic fractions in Rat --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory 47/0 Mathlib.lean,Mathlib/RingTheory/Localization/Rat.lean 2 1 ['github-actions'] robertylewis
assignee:robertylewis
47-62510
1 month ago
56-35446
1 month ago
56-35486
56 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 172/0 Counterexamples.lean,Counterexamples/DiscreteTopologyWithNontrivialValuation.lean 2 n/a ['github-actions', 'grunweg', 'kckennylau', 'pechersky'] nobody
47-47595
1 month ago
unknown
unknown
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
label:t-algebra$
88/0 Mathlib.lean,Mathlib/Algebra/MvPolynomial/Irreducible.lean 2 5 ['alreadydone', 'github-actions', 'mbkybky'] alreadydone
assignee:alreadydone
47-8898
1 month ago
83-37344
2 months ago
83-37380
83 days
25907 mans0954
author:mans0954
feat: low order roots of unity This PR continues the work from #25470. Original PR: https://github.com/leanprover-community/mathlib4/pull/25470 t-algebra
label:t-algebra$
182/0 Mathlib/Algebra/CharP/Invertible.lean,Mathlib/RingTheory/RootsOfUnity/Complex.lean 2 2 ['github-actions', 'mans0954'] kim-em
assignee:kim-em
47-8860
1 month ago
116-21551
3 months ago
116-21592
116 days
28531 Ruben-VandeVelde
author:Ruben-VandeVelde
chore: remove Cardinal imports from Topology.Algebra.InfiniteSum.Group --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) 51/15 Mathlib.lean,Mathlib/Analysis/BoxIntegral/UnitPartition.lean,Mathlib/Analysis/Normed/Group/Pointwise.lean,Mathlib/Analysis/Normed/Module/Convex.lean,Mathlib/Analysis/SpecificLimits/Basic.lean,Mathlib/Topology/Algebra/InfiniteSum/Const.lean,Mathlib/Topology/Algebra/InfiniteSum/Group.lean,Mathlib/Topology/Algebra/InfiniteSum/NatInt.lean,Mathlib/Topology/Algebra/InfiniteSum/Order.lean,Mathlib/Topology/Algebra/InfiniteSum/Real.lean,Mathlib/Topology/Category/Stonean/Basic.lean,Mathlib/Topology/Instances/ENNReal/Lemmas.lean,Mathlib/Topology/Instances/NNReal/Lemmas.lean,Mathlib/Topology/MetricSpace/HausdorffDistance.lean,Mathlib/Topology/MetricSpace/Thickening.lean,Mathlib/Topology/PartitionOfUnity.lean 16 4 ['Ruben-VandeVelde', 'YaelDillies', 'github-actions'] TwoFX
assignee:TwoFX
46-62476
1 month ago
53-73328
1 month ago
53-73304
53 days
28837 yury-harmonic
author:yury-harmonic
feat(ValMinAbs): add lemmas --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data 24/6 Mathlib/Data/ZMod/ValMinAbs.lean 1 1 ['github-actions'] nobody
46-39664
1 month ago
46-39674
1 month ago
46-39705
46 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
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 2 ['github-actions', 'mathlib4-merge-conflict-bot'] kim-em
assignee:kim-em
45-62481
1 month ago
54-58829
1 month ago
54-58805
54 days
28325 pechersky
author:pechersky
feat(WithZeroTopology): `locallyCompactSpace_iff_locallyFiniteOrder_units` On the way to golf/generalize the proof that locally compact valued fields have locally finite valuation groups as embodied in `Valued.integer.locallyFiniteOrder_units_mrange_of_isCompact_integer` ] --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) large-import t-order t-topology 160/2 Mathlib/Topology/Algebra/GroupWithZero.lean,Mathlib/Topology/Algebra/WithZeroTopology.lean,Mathlib/Topology/Compactness/Compact.lean 3 1 ['github-actions'] PatrickMassot
assignee:PatrickMassot
45-62478
1 month ago
57-44694
1 month ago
57-47397
57 days
23835 chrisflav
author:chrisflav
feat(Topology): cardinality of connected components is bounded by cardinality of fiber We show that if `f : X → Y` is an open and closed map to `Y` and `Y` is connected, the number of connected components of `X` is bounded by the cardinality of the fiber of any point. In particular, if `Y` has finitely many connected components and `f` finite fibers, also `X` as finitely many connected components. From Pi1. --- - [x] depends on: #23849 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-topology 242/1 Mathlib.lean,Mathlib/Data/Set/Lattice.lean,Mathlib/SetTheory/Cardinal/Finite.lean,Mathlib/Topology/Clopen.lean,Mathlib/Topology/Connected/CardComponents.lean,Mathlib/Topology/Connected/Clopen.lean 6 5 ['chrisflav', 'github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot'] grunweg
assignee:grunweg
44-62510
1 month ago
52-19659
1 month ago
54-13685
54 days
27824 ChrisHughes24
author:ChrisHughes24
feat(Calculus): exists_gt_of_deriv_pos and variants --- I created a new file for this as I anticipate there will be many lemmas relating derivatives and monotonicity in future. Some lemmas relating deriviatives to monotonicity are already in mathlib and should maybe moved to the file (e.g. docs#HasDerivWithinAt.nonneg_of_monotoneOn). I stated them in as much generality as I could, copying the generality of `HasDerivWithinAt.nonneg_of_monotoneOn`. - [x] depends on: #28039 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-analysis 85/0 Mathlib.lean,Mathlib/Analysis/Calculus/Deriv/Order.lean 2 29 ['ChrisHughes24', 'EtienneC30', 'github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] hrmacbeth
assignee:hrmacbeth
44-62507
1 month ago
55-6307
1 month ago
59-23997
59 days
25292 YaelDillies
author:YaelDillies
feat: the `ConvexCone` generated by a set Define `ConvexCone.copy` and `ConvexCone.hull` and use them to golf the `CompleteLattice` instance. From Toric --- - [x] depends on: #25291 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-convex-geometry toric 94/35 Mathlib/Analysis/Convex/Cone/Basic.lean,Mathlib/Geometry/Convex/Cone/Basic.lean 2 8 ['YaelDillies', 'b-mehta', 'github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot'] nobody
43-75596
1 month ago
74-28039
2 months ago
111-66358
111 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 16/0 Mathlib/Combinatorics/SimpleGraph/Trails.lean 1 6 ['IvanRenison', 'github-actions', 'vlad902'] kmill
assignee:kmill
43-24745
1 month ago
135-68271
4 months ago
135-68317
135 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 144/5 Mathlib/Data/PFunctor/Univariate/Basic.lean 1 19 ['alexkeizer', 'eric-wieser', 'github-actions', 'quangvdao'] eric-wieser
assignee:eric-wieser
43-9461
1 month ago
92-63568
3 months ago
92-63605
92 days
23238 YaelDillies
author:YaelDillies
feat: extended floor and ceil My motivation for this is to prove `ENat.toENNReal (⨆ i, f i) = ⨆ i, ENat.toENNReal (f i)` and `ENat.toENNReal (⨅ i, f i) = ⨅ i, ENat.toENNReal (f i)`. Kalle Kytölä independently needs this for his formalisation of statistical physics. From MiscYD --- - [x] depends on: #24781 - [x] depends on: #24782 See #15269 for a past attempt. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
235/0 Mathlib.lean,Mathlib/Algebra/Order/Floor/Extended.lean 2 25 ['YaelDillies', 'b-mehta', 'eric-wieser', 'github-actions', 'grunweg', 'kkytola', 'mathlib4-dependent-issues-bot', 'urkud'] alreadydone
assignee:alreadydone
43-3737
1 month ago
151-1102
4 months ago
198-53312
198 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
label:t-algebra$
74/0 Mathlib/RingTheory/Localization/Away/Basic.lean 1 17 ['eric-wieser', 'github-actions', 'grunweg', 'mathlib4-dependent-issues-bot', 'plp127', 'vihdzp'] mariainesdff
assignee:mariainesdff
42-62267
1 month ago
150-66882
4 months ago
216-66856
216 days
27392 Paul-Lez
author:Paul-Lez
feat(Tactic/SimpUtils): add simproc finding commands This PR adds some commands to allow users to find simprocs/dsimprocs/simp theorems that match on a given pattern. Thanks to Robin Arnez for telling me about `simprocDeclExt` :) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-meta 690/0 Mathlib.lean,Mathlib/Tactic.lean,Mathlib/Tactic/SimpUtils.lean,MathlibTest/SimpUtils.lean 4 9 ['Paul-Lez', 'eric-wieser', 'github-actions', 'kmill'] robertylewis
assignee:robertylewis
42-3397
1 month ago
64-76536
2 months ago
66-77199
66 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 471/0 Mathlib.lean,Mathlib/Geometry/Diffeology/Basic.lean,docs/references.bib 3 10 ['JovanGerb', 'github-actions', 'grunweg', 'lecopivo', 'peabrainiac'] grunweg
assignee:grunweg
41-34129
1 month ago
103-55345
3 months ago
103-60089
103 days
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 14/15 Mathlib/Tactic/Linter/CommandStart.lean 1 5 ['github-actions', 'leanprover-bot', 'leanprover-community-mathlib4-bot'] joneugster
assignee:joneugster
41-33885
1 month ago
110-71448
3 months ago
110-76052
110 days
27516 gaetanserre
author:gaetanserre
feat: add rational approximation lemma for suprema in `unitInterval` Add `sSup_eq_iUnion_rat` lemma that provides a rational approximation characterization of suprema in the unit interval. For monotone functions `f : α → I → ℝ`, the lemma establishes that the set of pairs where `a < sSup {x | f e.1 x < e.2}` equals the union over all rationals `q ∈ I` with `q > a` of the sets `{e | f e.1 q < e.2}`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-topology 44/0 Mathlib/MeasureTheory/Constructions/UnitInterval.lean,Mathlib/Topology/UnitInterval.lean 2 6 ['gaetanserre', 'github-actions', 'mathlib4-merge-conflict-bot', 'ocfnash'] ocfnash
assignee:ocfnash
41-11020
1 month ago
46-12739
1 month ago
72-3735
72 days
27433 YaelDillies
author:YaelDillies
refactor: make `⇑e⁻¹ = e.symm` simp From BrauerGroup and ClassFieldTheory --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) 217/256 Mathlib/Algebra/Algebra/Equiv.lean,Mathlib/Algebra/Group/End.lean,Mathlib/Algebra/Module/Equiv/Basic.lean,Mathlib/Algebra/Order/Rearrangement.lean,Mathlib/Data/Fintype/Perm.lean,Mathlib/FieldTheory/KrullTopology.lean,Mathlib/GroupTheory/Perm/Basic.lean,Mathlib/GroupTheory/Perm/Centralizer.lean,Mathlib/GroupTheory/Perm/Cycle/Basic.lean,Mathlib/GroupTheory/Perm/Cycle/Factors.lean,Mathlib/GroupTheory/Perm/Finite.lean,Mathlib/GroupTheory/Perm/Sign.lean,Mathlib/GroupTheory/Perm/Support.lean,Mathlib/GroupTheory/SpecificGroups/Alternating.lean,Mathlib/LinearAlgebra/Matrix/Determinant/Basic.lean,Mathlib/Logic/Equiv/Set.lean 16 3 ['eric-wieser', 'github-actions'] dwrensha
assignee:dwrensha
40-62522
1 month ago
53-16252
1 month ago
53-47616
53 days
28560 euprunin
author:euprunin
chore(Combinatorics/Quiver): golf entire `lift_spec` using `rfl` ---
Show trace profiling of lift_spec: <10 ms before, <10 ms after 🎉 ### Trace profiling of `lift_spec` before PR 28560 ```diff diff --git a/Mathlib/Combinatorics/Quiver/Symmetric.lean b/Mathlib/Combinatorics/Quiver/Symmetric.lean index 33e371b283..76a3371b36 100644 --- a/Mathlib/Combinatorics/Quiver/Symmetric.lean +++ b/Mathlib/Combinatorics/Quiver/Symmetric.lean @@ -164,6 +164,7 @@ def lift [HasReverse V'] (φ : Prefunctor V V') : | Sum.inl g => φ.map g | Sum.inr g => reverse (φ.map g) +set_option trace.profiler true in theorem lift_spec [HasReverse V'] (φ : Prefunctor V V') : Symmetrify.of.comp (Symmetrify.lift φ) = φ := by fapply Prefunctor.ext ``` ``` ✔ [147/147] Built Mathlib.Combinatorics.Quiver.Symmetric (1.3s) Build completed successfully (147 jobs). ``` ### Trace profiling of `lift_spec` after PR 28560 ```diff diff --git a/Mathlib/Combinatorics/Quiver/Symmetric.lean b/Mathlib/Combinatorics/Quiver/Symmetric.lean index 33e371b283..3adf874946 100644 --- a/Mathlib/Combinatorics/Quiver/Symmetric.lean +++ b/Mathlib/Combinatorics/Quiver/Symmetric.lean @@ -164,13 +164,10 @@ def lift [HasReverse V'] (φ : Prefunctor V V') : | Sum.inl g => φ.map g | Sum.inr g => reverse (φ.map g) +set_option trace.profiler true in theorem lift_spec [HasReverse V'] (φ : Prefunctor V V') : Symmetrify.of.comp (Symmetrify.lift φ) = φ := by - fapply Prefunctor.ext - · rintro X - rfl - · rintro X Y f - rfl + tauto theorem lift_reverse [h : HasInvolutiveReverse V'] (φ : Prefunctor V V') {X Y : Symmetrify V} (f : X ⟶ Y) : ``` ``` ✔ [147/147] Built Mathlib.Combinatorics.Quiver.Symmetric (1.2s) Build completed successfully (147 jobs). ```
--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)
t-combinatorics 2/6 Mathlib/Combinatorics/Quiver/Symmetric.lean 1 1 ['github-actions'] awainverse
assignee:awainverse
40-62515
1 month ago
53-4370
1 month ago
53-4413
53 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 35/0 Mathlib/Data/List/Scan.lean 1 9 ['ShreckYe', 'github-actions', 'themathqueen', 'vlad902'] nobody
40-37350
1 month ago
43-32597
1 month ago
43-32637
43 days
26843 vasnesterov
author:vasnesterov
feat(Tactic/Simproc): nested quantifiers in `existsAndEq` Generalize the `existsAndEq` simproc to nested existential quantifiers. For example `∃ a, p a ∧ ∃ b, a = f b ∧ q b` now simplifies to `∃ b, p (f b) ∧ q b`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) This PR continues the work from #23365. Original PR: https://github.com/leanprover-community/mathlib4/pull/23365 migrated-from-branch large-import t-meta 457/77 Mathlib/Combinatorics/SimpleGraph/Maps.lean,Mathlib/Data/List/ProdSigma.lean,Mathlib/Tactic/Simproc/ExistsAndEq.lean,MathlibTest/Simproc/ExistsAndEq.lean 4 15 ['JovanGerb', 'github-actions', 'grunweg', 'leanprover-bot', 'leanprover-community-bot-assistant', 'leanprover-community-mathlib4-bot', 'mathlib4-merge-conflict-bot', 'vasnesterov'] kmill
assignee:kmill
39-22108
1 month ago
39-75900
1 month ago
94-7033
94 days
25856 MichaelStollBayreuth
author:MichaelStollBayreuth
perf(Data.Real.Sqrt): make Real.sqrt irreducible We try to see what happens if we make Real.sqrt irreducible. There are cases where this makes unification very significantly faster, compare [#mathlib4 > Coercion triggers timeout @ 💬](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Coercion.20triggers.20timeout/near/517177117). (Migrated manually from #24752) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) migrated-from-branch t-data 7/5 Mathlib/Data/Real/Sqrt.lean 1 5 ['MichaelStollBayreuth', 'github-actions', 'j-loreaux', 'leanprover-bot'] ericrbg
assignee:ericrbg
38-76640
1 month ago
38-81356
1 month ago
108-21547
108 days
25920 BoltonBailey
author:BoltonBailey
feat(Data/Finsupp/Basic): `Finsupp.optionElim'` Similar to how Finsupp.cons constructs a map Fin (n + 1) →₀ M from a map Fin n →₀ M, we define Finsupp.optionElim' to construct a map Option α →₀ M from a map α →₀ M, given an additional value for none. We base this on the new optionEquiv definition. As a function, it behaves as Option.elim', hence the name. We prove a variety of API lemmas, based on those for Finsupp.cons, to bring the definitions more in line with the contents of Data/Finsupp/Fin. We also refactor to a new file to help avoid a too-long file and make this more analogous to Finsupp.cons Original PR: https://github.com/leanprover-community/mathlib4/pull/13861 - [x] depends on: #26309 migrated-from-branch t-data 114/23 Mathlib/Algebra/Category/MonCat/Adjunctions.lean,Mathlib/Data/Finsupp/Option.lean 2 15 ['BoltonBailey', 'eric-wieser', 'github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] eric-wieser
assignee:eric-wieser
38-42128
1 month ago
38-47174
1 month ago
103-17654
103 days
28602 gmcninch-tufts
author:gmcninch-tufts
feat(Algebra/Polynomial/Module): prove equivalence of a certain tensor product with PolynomialModule For a commutative ring `R` and an `R`-module `M`, construct an equivalence between the `R[X]`-modules `R[X] ⊗[R] M` and `PolynomialModule R M`. This equivalence enables application of some base-change results to `PolynomialModule R M` . --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-algebra
label:t-algebra$
210/0 Mathlib.lean,Mathlib/Algebra/Polynomial/Module/TensorProduct.lean 2 1 ['github-actions'] jcommelin
assignee:jcommelin
37-62501
1 month ago
52-11577
1 month ago
52-11614
52 days
26284 plp127
author:plp127
feat: faster implementation of `Nat.primeFactorsList` + `@[csimp]` lemma Add a function `Nat.primeFactorsListFast` that `#eval`s faster, and a `@[csimp]` lemma `Nat.primeFactorsList_eq_primeFactorsListFast` that shows `Nat.primeFactorsList = Nat.primeFactorsListFast`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data 95/0 Mathlib/Data/Nat/Factors.lean 1 5 ['b-mehta', 'github-actions', 'grunweg', 'plp127'] b-mehta
assignee:b-mehta
37-4831
1 month ago
108-49673
3 months ago
108-63581
108 days
28929 grunweg
author:grunweg
experiment: use `fun_prop` in Homeomorph Can we make the continuity auto-parameters use `fun_prop`? Or perhaps `first |fun_prop; |dsimp; fun_prop`? --- Compared to #13994, it seems this is a much smoother experience. I suspect the RefineDiscTree changes have helped (but that is pure speculation). [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-topology 13/5 Mathlib/MeasureTheory/Group/Measure.lean,Mathlib/Topology/Algebra/Algebra/Equiv.lean,Mathlib/Topology/Algebra/Constructions/DomMulAct.lean,Mathlib/Topology/Algebra/ContinuousMonoidHom.lean,Mathlib/Topology/Constructions/SumProd.lean,Mathlib/Topology/Homeomorph/Defs.lean 6 4 ['euprunin', 'github-actions', 'leanprover-bot', 'leanprover-community-mathlib4-bot'] PatrickMassot
assignee:PatrickMassot
36-62504
1 month ago
44-66782
1 month ago
44-72094
44 days
27308 xyzw12345
author:xyzw12345
feat(LinearAlgebra/SymmetricAlgebra): IsSymmetricAlgebra This PR continues the work from #24602. Original PR: https://github.com/leanprover-community/mathlib4/pull/24602 t-algebra
label:t-algebra$
78/0 Mathlib/LinearAlgebra/SymmetricAlgebra/Basic.lean,Mathlib/LinearAlgebra/SymmetricAlgebra/Basis.lean 2 3 ['github-actions', 'mattrobball', 'xyzw12345'] mattrobball
assignee:mattrobball
36-36610
1 month ago
81-13434
2 months ago
81-13479
81 days
28831 qawbecrdtey
author:qawbecrdtey
feat(Logic/Equiv/List): add `decodeList_encodeList_eq_self` and removed unnecessary linter options --- This is useful when we call `encode` and `decode` of a list to define a new `Encoder` involving `List`s. ```lean theorem decodeList_encodeList_eq_self (l : List α) : decodeList (encodeList l) = some l ``` [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-logic 7/6 Mathlib/Logic/Equiv/List.lean 1 1 ['github-actions'] awainverse
assignee:awainverse
35-62508
1 month ago
46-56552
1 month ago
46-56586
46 days
28906 gasparattila
author:gasparattila
feat(Topology/Algebra/Module): `prod` and `coprod` as `ContinuousLinearEquiv`s --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-topology 36/5 Mathlib/Topology/Algebra/Module/LinearMapPiProd.lean,Mathlib/Topology/Algebra/Module/StrongTopology.lean 2 1 ['github-actions'] jcommelin
assignee:jcommelin
35-62507
1 month ago
45-2674
1 month ago
45-2707
45 days
26790 FlAmmmmING
author:FlAmmmmING
feat(Combinatorics/Enumerative/Bell.lean): define standard Bell number --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-combinatorics 46/1 Mathlib/Combinatorics/Enumerative/Bell.lean 1 11 ['AntoineChambert-Loir', 'FlAmmmmING', 'eric-wieser', 'github-actions', 'kckennylau', 'madvorak'] awainverse
assignee:awainverse
35-44777
1 month ago
96-7903
3 months ago
96-7941
96 days
26986 WangYiran01
author:WangYiran01
feat(Partition): add bijection for partitions with max part ≤ r ## Summary This PR adds a new theorem `partition_max_equals_bound` to `Mathlib.Combinatorics.Enumerative.Partition`. It constructs a bijection between: - The set of partitions of `n` in which `r ∈ π.parts` and all parts are `≤ r`, and - The set of partitions of `n - r` whose largest part is at most `r`. This provides a constructive proof via removing/adding `r` from/to the partition multiset, in line with classical enumerative combinatorics. ## Implementation notes - The proof uses `Multiset.erase` and `Multiset.cons` with basic properties of `sum`, `sup`, and `Partition` structures. - The bijection is implemented explicitly via `f` and `g`, and proven mutually inverse via `Subtype.ext`. ## Linting - [x] Passes `lake build` - [x] Linter clean (no commandStart or longLine issues) ## Author Contributed by Yiran Wang. new-contributor t-combinatorics 85/0 Mathlib/Combinatorics/Enumerative/Partition.lean 1 3 ['WangYiran01', 'github-actions'] b-mehta
assignee:b-mehta
35-41311
1 month ago
90-32463
2 months ago
90-32499
90 days
29307 harahu
author:harahu
doc: hyphenate attributive compound adjectives ending in "exact" Compound adjectives that are attributive (coming before their noun) should almost always be hyphenated in English. This PR covers such adjectives that are ending in "exact". --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) 144/144 Mathlib/Algebra/Category/ContinuousCohomology/Basic.lean,Mathlib/Algebra/Category/ModuleCat/Free.lean,Mathlib/Algebra/Homology/ConcreteCategory.lean,Mathlib/Algebra/Homology/DerivedCategory/Basic.lean,Mathlib/Algebra/Homology/DerivedCategory/Ext/ExactSequences.lean,Mathlib/Algebra/Homology/DerivedCategory/Ext/ExtClass.lean,Mathlib/Algebra/Homology/DerivedCategory/HomologySequence.lean,Mathlib/Algebra/Homology/DerivedCategory/ShortExact.lean,Mathlib/Algebra/Homology/DerivedCategory/SingleTriangle.lean,Mathlib/Algebra/Homology/HomologySequence.lean,Mathlib/Algebra/Homology/HomologySequenceLemmas.lean,Mathlib/Algebra/Homology/HomotopyCategory/DegreewiseSplit.lean,Mathlib/Algebra/Homology/HomotopyCategory/HomologicalFunctor.lean,Mathlib/Algebra/Homology/HomotopyCategory/Pretriangulated.lean,Mathlib/Algebra/Homology/HomotopyCategory/ShortExact.lean,Mathlib/Algebra/Homology/LocalCohomology.lean,Mathlib/Algebra/Homology/ShortComplex/ExactFunctor.lean,Mathlib/Algebra/Homology/ShortComplex/ShortExact.lean,Mathlib/Algebra/Lie/Extension.lean,Mathlib/CategoryTheory/Abelian/DiagramLemmas/KernelCokernelComp.lean,Mathlib/CategoryTheory/Abelian/GrothendieckAxioms/Basic.lean,Mathlib/CategoryTheory/Abelian/GrothendieckCategory/ModuleEmbedding/GabrielPopescu.lean,Mathlib/CategoryTheory/Functor/Flat.lean,Mathlib/CategoryTheory/Limits/ExactFunctor.lean,Mathlib/CategoryTheory/Limits/Preserves/Finite.lean,Mathlib/CategoryTheory/Limits/Preserves/Presheaf.lean,Mathlib/CategoryTheory/ObjectProperty/Extensions.lean,Mathlib/CategoryTheory/Preadditive/AdditiveFunctor.lean,Mathlib/CategoryTheory/Preadditive/LeftExact.lean,Mathlib/CategoryTheory/Shift/ShiftSequence.lean,Mathlib/CategoryTheory/Sites/Grothendieck.lean,Mathlib/CategoryTheory/Sites/LeftExact.lean,Mathlib/CategoryTheory/Sites/MayerVietorisSquare.lean,Mathlib/CategoryTheory/Sites/NonabelianCohomology/H1.lean,Mathlib/CategoryTheory/Sites/Sheafification.lean,Mathlib/CategoryTheory/Triangulated/HomologicalFunctor.lean,Mathlib/GroupTheory/GroupExtension/Defs.lean,Mathlib/GroupTheory/MonoidLocalization/GrothendieckGroup.lean,Mathlib/LinearAlgebra/TensorProduct/RightExactness.lean,Mathlib/RepresentationTheory/Coinvariants.lean,Mathlib/RepresentationTheory/Homological/GroupCohomology/LongExactSequence.lean,Mathlib/RepresentationTheory/Homological/GroupHomology/LongExactSequence.lean,Mathlib/RingTheory/DedekindDomain/SelmerGroup.lean,Mathlib/RingTheory/Flat/CategoryTheory.lean,Mathlib/RingTheory/Ideal/AssociatedPrime/Finiteness.lean,Mathlib/RingTheory/Regular/IsSMulRegular.lean,Mathlib/Topology/Category/Profinite/Nobeling/Successor.lean 47 n/a ['github-actions'] nobody
35-38978
1 month ago
unknown
unknown
27254 yuanyi-350
author:yuanyi-350
2025 imo problem3 - [x] depends on: #28788 - [x] depends on: #28790 - [x] depends on: #28829 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) IMO 231/0 Archive.lean,Archive/Imo/Imo2025Q3.lean,Mathlib/NumberTheory/Padics/PadicVal/Basic.lean 3 28 ['github-actions', 'jsm28', 'kbuzzard', 'leanprover-community-bot-assistant', 'madvorak', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'themathqueen', 'wwylele', 'yuanyi-350'] jsm28
assignee:jsm28
35-28926
1 month ago
36-64592
1 month ago
70-39456
70 days
26277 AntoineChambert-Loir
author:AntoineChambert-Loir
feat(RingTheory/Congruence/Hom): prove basic isomorphisms theorems for ring congruences This file contains elementary definitions involving congruence relations and morphisms for semirings, rings, and algebras. * `RingCon.ker`: the kernel of a monoid homomorphism as a congruence relation * `RingCon.lift`, `RingCon.liftₐ`: the homomorphism / the algebra morphism on the quotient given that the congruence is in the kernel * `RingCon.map`, `RingCon.mapₐ`: homomorphism / algebra morphism from a smaller to a larger quotient * `RingCon.quotientKerEquivRangeS`, `RingCon.quotientKerEquivRange`, `RingCon.quotientKerEquivRangeₐ` : the first isomorphism theorem for semirings (using `RingHom.rangeS`), rings (using `RingHom.range`) and algebras (using `AlgHom.range`). * `RingCon.comapQuotientEquivRangeS`, `RingCon.comapQuotientEquivRange`, `RingCon.comapQuotientEquivRangeₐ` : the second isomorphism theorem for semirings (using `RingHom.rangeS`), rings (using `RingHom.range`) and algebras (using `AlgHom.range`). * `RingCon.quotientQuotientEquivQuotient`, `RingCon.quotientQuotientEquivQuotientₐ` : the third isomorphism theorem for semirings (or rings) and algebras It is an adaptation of what existed for multiplicative congruences (docs#Con) and is only useful for semirings which are not rings. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory 554/2 Mathlib.lean,Mathlib/Algebra/Ring/Subsemiring/Basic.lean,Mathlib/Algebra/RingQuot.lean,Mathlib/RingTheory/Congruence/Defs.lean,Mathlib/RingTheory/Congruence/Hom.lean 5 4 ['AntoineChambert-Loir', 'eric-wieser', 'github-actions'] joneugster
assignee:joneugster
34-39158
1 month ago
65-31544
2 months ago
108-74159
108 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 52 ['b-mehta', 'espottesmith', 'github-actions', 'jt496', 'lauramonk', 'mathlib4-merge-conflict-bot'] b-mehta
assignee:b-mehta
34-28554
1 month ago
34-28554
1 month ago
40-14737
40 days
29028 themathqueen
author:themathqueen
feat(Algebra/Star): define `unitary R →* StarAlgEquiv S R R` Every unitary defines a star-algebra automorphism (this is an extension of a special version of `MulSemiringAction.toRingEquiv` for unitaries). --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
64/0 Mathlib.lean,Mathlib/Algebra/Star/UnitaryStarAlgAut.lean 2 14 ['eric-wieser', 'github-actions', 'themathqueen'] eric-wieser
assignee:eric-wieser
34-7150
1 month ago
41-31039
1 month ago
43-1644
43 days
19046 j-loreaux
author:j-loreaux
feat: define class `SemigroupAction` --- If I can get this building with minimal performance impact, I would like to change the names to: `MulAction → MonoidAction` `SemigroupAction → MulAction` [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
48/26 Mathlib/Algebra/Azumaya/Matrix.lean,Mathlib/Algebra/Category/ModuleCat/Presheaf.lean,Mathlib/Algebra/Group/Action/Defs.lean,Mathlib/Algebra/Group/Action/Hom.lean,Mathlib/Algebra/Group/Action/Prod.lean,Mathlib/Algebra/Group/Action/TypeTags.lean,Mathlib/Algebra/Polynomial/Laurent.lean,Mathlib/GroupTheory/CoprodI.lean,Mathlib/LinearAlgebra/Eigenspace/Matrix.lean,Mathlib/LinearAlgebra/FreeModule/Finite/Quotient.lean,Mathlib/LinearAlgebra/Matrix/SesquilinearForm.lean,Mathlib/NumberTheory/ModularForms/CongruenceSubgroups.lean,Mathlib/RingTheory/Trace/Basic.lean 13 10 ['alreadydone', 'github-actions', 'j-loreaux', 'leanprover-bot', 'leanprover-community-mathlib4-bot', 'urkud'] jcommelin
assignee:jcommelin
33-62510
1 month ago
41-78740
1 month ago
48-19626
48 days
28311 eric-wieser
author:eric-wieser
fix(Tactic/NormNum): do not hang on large powers This uses `Lean.checkExponent` to guard against large powers. Unfortunately the log messages it emits are currently swallowed, but surfacing these may require changing the API for norm_num extensions (to live in `OptionT MetaM`) and so is left to future work. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-meta bug 41/23 Mathlib/Tactic/NormNum/Pow.lean,Mathlib/Tactic/Ring/Basic.lean,MathlibTest/norm_num.lean,MathlibTest/norm_num_ext.lean 4 4 ['github-actions', 'mathlib4-merge-conflict-bot'] robertylewis
assignee:robertylewis
33-62508
1 month ago
42-69164
1 month ago
50-35979
50 days
29040 PMKielstra
author:PMKielstra
feat: trapezoidal rule for integration This PR defines the trapezoidal rule and proves the standard error bound on it in terms of bounds on the second derivative. I have vague plans of using this plus interval arithmetic to develop a tactic that can automatically close goals of the form `\integral x in a..b, f x < y` or similar. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-measure-probability 273/0 Mathlib.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral/Basic.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral/TrapezoidalRule.lean 3 40 ['PMKielstra', 'github-actions', 'tb65536'] kex-y
assignee:kex-y
33-62504
1 month ago
42-69397
1 month ago
42-69834
42 days
29042 vihdzp
author:vihdzp
feat(SetTheory/Ordinal/Exponential): generalize theorems from `y = succ x` to `x < y` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-set-theory 18/6 Mathlib/SetTheory/Ordinal/Exponential.lean 1 1 ['github-actions'] b-mehta
assignee:b-mehta
33-62503
1 month ago
42-59145
1 month ago
42-59129
42 days
29082 grunweg
author:grunweg
RFC: tag `IsInducing` and `Is{Open,Closed,}Embedding` with `fun_prop` I have not tested if this is usable in practice; perhaps it is not. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-topology 37/5 Mathlib/Topology/Constructions.lean,Mathlib/Topology/Defs/Induced.lean,Mathlib/Topology/Maps/Basic.lean 3 1 ['github-actions'] jcommelin
assignee:jcommelin
33-62501
1 month ago
41-81153
1 month ago
41-81184
41 days
28140 YaelDillies
author:YaelDillies
feat: a `PointedCone`-valued version of `Submodule.span` This is merely to guide typing. From Toric --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-convex-geometry toric 11/2 Mathlib/Geometry/Convex/Cone/Dual.lean,Mathlib/Geometry/Convex/Cone/Pointed.lean 2 2 ['github-actions', 'mathlib4-merge-conflict-bot'] nobody
33-8635
1 month ago
33-8666
1 month ago
61-3553
61 days
28339 JovanGerb
author:JovanGerb
feat(gcongr): support `@[gcongr]` for `Monotone` and friends This PR adds the feature to `gcongr` that you can now tag lemmas whose conclusion is `Monotone f`, `Antitone f`, etc. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-meta 119/88 Mathlib/Algebra/Order/Floor/Ring.lean,Mathlib/Algebra/Order/Floor/Semiring.lean,Mathlib/Algebra/Order/Module/Algebra.lean,Mathlib/Algebra/Order/Ring/Cast.lean,Mathlib/Algebra/Ring/Subring/Basic.lean,Mathlib/Analysis/Complex/Exponential.lean,Mathlib/Analysis/SpecialFunctions/Log/ERealExp.lean,Mathlib/Analysis/SpecialFunctions/Trigonometric/Arctan.lean,Mathlib/Data/Finsupp/Order.lean,Mathlib/Data/Multiset/Defs.lean,Mathlib/Data/Nat/Cast/Order/Basic.lean,Mathlib/Data/Rat/Cast/Order.lean,Mathlib/Data/Real/Sqrt.lean,Mathlib/LinearAlgebra/Basis/Flag.lean,Mathlib/MeasureTheory/Function/SimpleFunc.lean,Mathlib/Order/Filter/Map.lean,Mathlib/Order/Hom/Basic.lean,Mathlib/Order/KrullDimension.lean,Mathlib/Tactic/GCongr/Core.lean,MathlibTest/GCongr/inequalities.lean 20 4 ['github-actions', 'kckennylau', 'mathlib4-merge-conflict-bot'] adamtopaz
assignee:adamtopaz
32-62495
1 month ago
44-10725
1 month ago
56-67341
56 days
28833 yury-harmonic
author:yury-harmonic
feat(MvPolynomial/Expand): more lemmas --- - [x] depends on: #28832 - [x] depends on: #28830 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) 88/18 Mathlib/Algebra/MvPolynomial/Eval.lean,Mathlib/Algebra/MvPolynomial/Expand.lean 2 2 ['github-actions', 'mathlib4-dependent-issues-bot'] dwrensha
assignee:dwrensha
32-62493
1 month ago
45-79234
1 month ago
45-80982
45 days
28511 YaelDillies
author:YaelDillies
feat(Finsupp): `congr!`-compatible version of `prod_congr` `congr!` doesn't like the `g1 x (f x)` appearing in the hypothesis of `Finsupp.prod_congr`: `f x` isn't a free variable. Note: A few proofs broke due to `simp` using `congr` lemmas internally. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
17/11 Mathlib/Algebra/BigOperators/Finsupp/Basic.lean,Mathlib/Algebra/Category/MonCat/Adjunctions.lean,Mathlib/Data/Finsupp/Multiset.lean,Mathlib/Data/Nat/Choose/Multinomial.lean,Mathlib/RepresentationTheory/Homological/GroupHomology/LowDegree.lean 5 12 ['JovanGerb', 'YaelDillies', 'eric-wieser', 'github-actions', 'kmill'] kmill
assignee:kmill
32-27188
1 month ago
54-33643
1 month ago
54-33677
54 days
26453 jburroni
author:jburroni
feat(Data/PNat/Basic): add order-related instances to PNat Add `SuccAddOrder ℕ+` and `NoMaxOrder ℕ+` instances. This allows, for example, the use of lemmas related to `Intervals` built with ℕ+. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data new-contributor 31/0 Mathlib.lean,Mathlib/Data/PNat/Order.lean 2 14 ['Ruben-VandeVelde', 'eric-wieser', 'github-actions', 'jburroni', 'vihdzp'] ericrbg
assignee:ericrbg
31-1970
1 month ago
31-6974
1 month ago
101-9284
101 days
27567 themathqueen
author:themathqueen
feat(LinearAlgebra/TensorProduct/Associator): add `lid` and `assoc` tensor lemmas This adds `TensorProduct.lid_tensor` and `TensorProduct.assoc_tensor`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra easy
label:t-algebra$
31/2 Mathlib/LinearAlgebra/TensorProduct/Associator.lean,Mathlib/LinearAlgebra/TensorProduct/Basic.lean 2 3 ['github-actions', 'themathqueen'] mattrobball
assignee:mattrobball
30-8154
1 month ago
59-84077
1 month ago
73-76906
73 days
28695 chrisflav
author:chrisflav
feat(RingTheory): meta properties of bijective ring homomorphisms In particular, we show that bijective is a property local on the (algebraic) source. --- - [x] depends on: #28642 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory large-import 170/7 Mathlib.lean,Mathlib/Algebra/Algebra/Basic.lean,Mathlib/Algebra/Algebra/Hom.lean,Mathlib/LinearAlgebra/TensorProduct/Basic.lean,Mathlib/RingTheory/LocalProperties/Exactness.lean,Mathlib/RingTheory/LocalRing/ResidueField/Instances.lean,Mathlib/RingTheory/Localization/Algebra.lean,Mathlib/RingTheory/Localization/Away/Basic.lean,Mathlib/RingTheory/Localization/Basic.lean,Mathlib/RingTheory/RingHom/Bijective.lean,Mathlib/RingTheory/TensorProduct/Basic.lean 11 2 ['github-actions', 'mathlib4-dependent-issues-bot'] kbuzzard
assignee:kbuzzard
26-62514
26 days ago
36-82173
1 month ago
36-85215
36 days
24184 YaelDillies
author:YaelDillies
feat: `[G : H]` notation for the index of `H : Subgroup G` This is a cute notation which I wrote for FLT. Not sure whether we want it in mathlib nor how to include `relindex` in the picture. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra RFC
label:t-algebra$
5/0 Mathlib/GroupTheory/Index.lean 1 8 ['YaelDillies', 'erdOne', 'github-actions', 'j-loreaux', 'kbuzzard', 'mathlib4-merge-conflict-bot'] eric-wieser
assignee:eric-wieser
25-83800
25 days ago
25-83825
25 days ago
173-71540
173 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
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 11 ['JovanGerb', 'adomani', 'alreadydone', 'bryangingechen', 'github-actions', 'mathlib4-merge-conflict-bot'] bryangingechen
assignee:bryangingechen
25-76067
25 days ago
25-83214
25 days ago
64-46096
64 days
27252 Parcly-Taxel
author:Parcly-Taxel
feat: sharp bounds for `‖exp (I * x) - 1‖` when `x` is real From Carleson carleson t-analysis 44/0 Mathlib/Analysis/Complex/Trigonometric.lean,Mathlib/Analysis/SpecialFunctions/Trigonometric/Bounds.lean 2 13 ['Parcly-Taxel', 'eric-wieser', 'github-actions', 'grunweg', 'mathlib4-merge-conflict-bot'] hrmacbeth
assignee:hrmacbeth
25-62489
25 days ago
33-28514
1 month ago
34-34971
34 days
29055 vihdzp
author:vihdzp
feat: `Ordinal.toENat` We essentially copy the Cardinal/ENat file but make it for ordinals instead. See [Zulip](https://leanprover.zulipchat.com/#narrow/channel/144837-PR-reviews/topic/.2317758.20Ordinal.2EtoENat/near/479768508) for some prior discussion on this PR (particularly, the duplication and how there's no easy way to resolve it.) --- Moved from #17758. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-set-theory 292/0 Mathlib.lean,Mathlib/Data/ENat/Basic.lean,Mathlib/SetTheory/Cardinal/ENat.lean,Mathlib/SetTheory/Ordinal/Arithmetic.lean,Mathlib/SetTheory/Ordinal/Basic.lean,Mathlib/SetTheory/Ordinal/ENat.lean 6 1 ['github-actions'] alreadydone
assignee:alreadydone
25-62487
25 days ago
42-28719
1 month ago
42-28736
42 days
22039 YaelDillies
author:YaelDillies
feat: simproc for computing `Finset.Ixx` of natural numbers --- - [x] depends on: #22290 - [x] depends on: #22559 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) large-import t-meta 315/0 Mathlib.lean,Mathlib/Tactic.lean,Mathlib/Tactic/Simproc/FinsetInterval.lean,Mathlib/Util/Qq.lean 4 64 ['FLDutchmann', 'Paul-Lez', 'YaelDillies', 'eric-wieser', 'github-actions', 'grunweg', 'kckennylau', 'kim-em', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'urkud'] eric-wieser
assignee:eric-wieser
25-30974
25 days ago
176-29206
5 months ago
231-76317
231 days
26544 vihdzp
author:vihdzp
feat(SetTheory/ZFC/Ordinal): Lean ordinals to ZFC ordinals We define `Ordinal.toZFSet` and prove that its outputs are precisely the ZFC ordinals. Moved from #19985. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) large-import t-set-theory 166/5 Mathlib/SetTheory/ZFC/Basic.lean,Mathlib/SetTheory/ZFC/Ordinal.lean,Mathlib/SetTheory/ZFC/PSet.lean,Mathlib/SetTheory/ZFC/Rank.lean 4 23 ['alreadydone', 'github-actions', 'leanprover-community-bot-assistant', 'staroperator', 'vihdzp'] b-mehta
assignee:b-mehta
24-62482
24 days ago
32-31040
1 month ago
59-8397
59 days
22043 YaelDillies
author:YaelDillies
chore: shortcut instance for `Neg ℤˣ` This lets us avoid importing `Ring` in downstream files (most of the effect is to come). --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) file-removed t-algebra
label:t-algebra$
20/47 Mathlib.lean,Mathlib/Algebra/GCDMonoid/Nat.lean,Mathlib/Algebra/Group/Int/Units.lean,Mathlib/Algebra/Order/Ring/Abs.lean,Mathlib/Algebra/Ring/Int/Units.lean,Mathlib/Algebra/Ring/NegOnePow.lean,Mathlib/Data/Fintype/Units.lean,Mathlib/Data/Int/AbsoluteValue.lean,Mathlib/Data/Int/Associated.lean,Mathlib/GroupTheory/HNNExtension.lean,Mathlib/NumberTheory/NumberField/Basic.lean,MathlibTest/Zify.lean 12 17 ['YaelDillies', 'erdOne', 'eric-wieser', 'github-actions', 'j-loreaux', 'leanprover-community-bot-assistant', 'mathlib-bors'] eric-wieser
assignee:eric-wieser
24-34895
24 days ago
148-17932
4 months ago
232-77357
232 days
29668 harahu
author:harahu
doc: cleanup of kleene star docs This PR: - Corrects "Kleene's star" to "Kleene star" - Clarifies a comment about notation. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-computability 5/5 Mathlib/Computability/Language.lean 1 1 ['github-actions'] nobody
24-30908
24 days ago
24-30916
24 days ago
24-30949
24 days
28533 kim-em
author:kim-em
feat(linarith): add `linarith?` mode which suggests a `linarith only` call Adds `linarith?`, which traces the internal to watch which inequalities are being used, and suggests a `linarith only` call via the "try this:" mechanism. Also adds a `+minimize` flag, on by default, which then greedily tries to drop hypotheses from the used set, to see if the problem is still possible with a smaller set. Currently I don't have test case showing this is worthwhile, however. Contributions welcome. ------ https://chatgpt.com/codex/tasks/task_e_68a02bce93a883218485c7e7cafb877a codex t-meta 212/68 Mathlib/Tactic/Linarith/Frontend.lean,Mathlib/Tactic/Linarith/Verification.lean,MathlibTest/linarith.lean 3 12 ['YaelDillies', 'eric-wieser', 'github-actions', 'hrmacbeth', 'jcommelin', 'kim-em', 'mathlib4-merge-conflict-bot'] robertylewis
assignee:robertylewis
24-19222
24 days ago
37-55013
1 month ago
53-54372
53 days
26580 vasnesterov
author:vasnesterov
feat(Tactic/Order): translate linear orders to `Int` It was [pointed out](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/tactic.20for.20partial.20orders/near/515897754) that `order` is not complete for linear orders with lattice operations (while it remains complete for linear orders without lattice operations and for general lattices without assuming linearity). The problem for linear orders with lattice operations is NP-hard, but it can be translated from an arbitrary type to `Int` and then solved using a smart and efficient procedure (such as `omega`). This PR implements such a translation within the `order` tactic. Co-authored-by: Aaron Liu --- - [x] depends on: #26354 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-meta 300/29 Mathlib.lean,Mathlib/Tactic.lean,Mathlib/Tactic/Order.lean,Mathlib/Tactic/Order/Graph/Basic.lean,Mathlib/Tactic/Order/Preprocessing.lean,Mathlib/Tactic/Order/ToInt.lean,MathlibTest/order.lean 7 5 ['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'vasnesterov'] alexjbest
assignee:alexjbest
24-9883
24 days ago
24-9891
24 days ago
88-24194
88 days
26110 YaelDillies
author:YaelDillies
feat: sharp monoids Define sharp monoids, which are the monoids whose only unit is `1`. This concept is useful in log geometry and in particular shows up in the theory of affine monoids. This concept already existed in the guise of `Subsingleton Mˣ`, but giving it a name makes it easier to refer to and uncovers some missing instances. From Toric --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) toric t-algebra
label:t-algebra$
51/30 Mathlib/Algebra/BigOperators/Associated.lean,Mathlib/Algebra/BigOperators/Group/Finset/Basic.lean,Mathlib/Algebra/GCDMonoid/Basic.lean,Mathlib/Algebra/Group/Irreducible/Defs.lean,Mathlib/Algebra/Group/Pi/Units.lean,Mathlib/Algebra/Group/Prod.lean,Mathlib/Algebra/Group/Submonoid/Units.lean,Mathlib/Algebra/Group/Units/Basic.lean,Mathlib/Algebra/Group/Units/Defs.lean,Mathlib/Algebra/GroupWithZero/Associated.lean,Mathlib/Algebra/GroupWithZero/Divisibility.lean,Mathlib/Data/List/Prime.lean,Mathlib/Data/ZMod/Basic.lean,Mathlib/NumberTheory/DirichletCharacter/Basic.lean,Mathlib/RingTheory/ChainOfDivisors.lean,Mathlib/RingTheory/IntegralDomain.lean,Mathlib/RingTheory/UniqueFactorizationDomain/NormalizedFactors.lean,Mathlib/RingTheory/Valuation/Integers.lean 18 7 ['YaelDillies', 'b-mehta', 'github-actions', 'leanprover-community-bot-assistant', 'mathlib4-merge-conflict-bot', 'vihdzp'] adomani
assignee:adomani
24-9033
24 days ago
28-3464
28 days ago
112-3506
112 days
29422 jsm28
author:jsm28
fix(Data/Finset/Max): Use `DecidableEq` for `insert` lemmas These `insert` in these lemma statements uses a `DecidableEq` instance derived from `LinearOrder`; make them syntactically more general by passing in a `DecidableEq` instance separately. (Some `insert` lemmas in this file already take `DecidableEq` hypotheses.) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data 8/8 Mathlib/Data/Finset/Max.lean 1 2 ['eric-wieser', 'github-actions'] nobody
24-4773
24 days ago
31-60451
1 month ago
31-60428
31 days
28884 kim-em
author:kim-em
chore: deprecate ShiftLeft Int instance This PR proposes deprecating the `ShiftLeft Int` instance (which allows bit-shifting an integer by an integer), and similarly for `ShiftRight`. These are unused in Mathlib. I'm happy if someone wants to keep this, but I would ask that they: * fix the doc-strings to explain what happens for negative shifts * ~~restores the theorem `Int.shiftLeft_add` which I've commented out on `nightly-testing` (and then revert b33c9d7aaea on `nightly-testing`).~~ * ideally but optionally, complete the API, e.g. reducing shifts by casts back to shifts by a Nat t-data 22/3 Mathlib/Data/Int/Bitwise.lean 1 5 ['eric-wieser', 'github-actions', 'kim-em', 'mathlib4-merge-conflict-bot'] nobody
23-62492
23 days ago
23-62510
23 days ago
45-30608
45 days
28973 YaelDillies
author:YaelDillies
feat(TensorProduct): `lTensor` as an `AlgHom` and other lemmas From Toric Co-authored-by: Michał Mrugała --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory toric 21/0 Mathlib/RingTheory/TensorProduct/Basic.lean 1 7 ['YaelDillies', 'eric-wieser', 'github-actions', 'themathqueen'] mattrobball
assignee:mattrobball
23-43870
23 days ago
23-63468
23 days ago
20-32669
20 days
29132 YaelDillies
author:YaelDillies
feat(AdjoinRoot): bundle operations as `AlgHom`s In particular, generalise and rename `liftHom` to use a general `eval₂` instead of `aeval`. From Toric Co-authored-by: Andrew Yang the.erd.one@gmail.com Co-authored-by: Michał Mrugała kiolterino@gmail.com --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory toric 164/103 Mathlib/Algebra/Algebra/Hom.lean,Mathlib/FieldTheory/IntermediateField/Adjoin/Basic.lean,Mathlib/FieldTheory/Isaacs.lean,Mathlib/FieldTheory/KummerExtension.lean,Mathlib/FieldTheory/Minpoly/IsIntegrallyClosed.lean,Mathlib/RingTheory/Adjoin/Field.lean,Mathlib/RingTheory/AdjoinRoot.lean,Mathlib/RingTheory/LocalRing/ResidueField/Instances.lean,Mathlib/RingTheory/Localization/Away/AdjoinRoot.lean 9 3 ['erdOne', 'github-actions', 'mathlib4-merge-conflict-bot'] erdOne
assignee:erdOne
22-62505
22 days ago
37-13417
1 month ago
39-23874
39 days
27292 gasparattila
author:gasparattila
feat: asymptotic cone of a set This PR defines the asymptotic cone of a set in a normed affine space and proves its main properties. This is partial progress towards showing that an unbounded finite-dimensional convex set contains a ray. --- - [x] depends on: #27221 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) maintainer-merge new-contributor t-analysis 466/0 Mathlib.lean,Mathlib/Analysis/Normed/Affine/AsymptoticCone.lean,Mathlib/Order/Filter/Map.lean,Mathlib/Topology/Algebra/AsymptoticCone.lean 4 45 ['AntoineChambert-Loir', 'YaelDillies', 'gasparattila', 'github-actions', 'mathlib4-dependent-issues-bot'] YaelDillies
assignee:YaelDillies
22-44044
22 days ago
65-5937
2 months ago
79-23470
79 days
29437 NotWearingPants
author:NotWearingPants
feat(Data/Seq): add Seq.subsequence and prove basic theorems about it I added `Seq.subsequence` to compose a sequence with a monotone function, creating a subsequence. Aliased to `Seq.comp` since it's a composition. I also added `Nat.le_induction_step_iff` which is needed to prove a subsequence is a sequence. This proves the comment at the top of `Defs.lean` that says "if `f n = none`, then `f m = none` for all `m ≥ n`" while `IsSeq` only talks about `n+1`. For completion I added the same statement for `Int`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) large-import t-data new-contributor 114/0 Mathlib/Data/Int/Init.lean,Mathlib/Data/Nat/Init.lean,Mathlib/Data/Seq/Basic.lean,Mathlib/Data/Seq/Defs.lean 4 2 ['github-actions', 'mathlib4-merge-conflict-bot'] nobody
22-23288
22 days ago
22-23309
22 days ago
31-10798
31 days
26129 LessnessRandomness
author:LessnessRandomness
feat(Geometry/Euclidean/Angle/Unoriented): triangle inequality for angles This PR continues the work from #24206. Original PR: https://github.com/leanprover-community/mathlib4/pull/24206 new-contributor t-euclidean-geometry 203/16 Mathlib.lean,Mathlib/Analysis/Fourier/FiniteAbelian/Orthogonality.lean,Mathlib/Analysis/InnerProductSpace/Basic.lean,Mathlib/Analysis/InnerProductSpace/PiL2.lean,Mathlib/Geometry/Euclidean/Angle/Unoriented/Affine.lean,Mathlib/Geometry/Euclidean/Angle/Unoriented/Basic.lean,Mathlib/Geometry/Euclidean/Angle/Unoriented/TriangleInequality.lean,Mathlib/Geometry/Manifold/Instances/Sphere.lean 8 76 ['JovanGerb', 'LessnessRandomness', 'Timeroot', 'github-actions', 'jsm28', 'mathlib4-merge-conflict-bot', 'themathqueen'] jsm28
assignee:jsm28
22-4125
22 days ago
34-67242
1 month ago
110-8633
110 days
29324 tb65536
author:tb65536
refactor(Analysis/Calculus/IteratedDeriv/Defs): tweak statement of `iteratedDerivWithin_one` This PR removes the `x` from `iteratedDerivWithin_one` to make it match `iteratedDerivWithin_zero`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-analysis 3/2 Mathlib/Analysis/Calculus/IteratedDeriv/Defs.lean 1 3 ['Ruben-VandeVelde', 'github-actions', 'grunweg'] grunweg
assignee:grunweg
22-278
22 days ago
35-82620
1 month ago
35-82597
35 days
29756 Ruben-VandeVelde
author:Ruben-VandeVelde
feat: Finsupp.comapDomain_surjective --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) FLT t-data 9/0 Mathlib/Data/Finsupp/Basic.lean 1 1 ['github-actions'] nobody
21-80416
21 days ago
21-80454
21 days ago
21-80490
21 days
26961 mariainesdff
author:mariainesdff
feat(RingTheory/PowerSeries/Substitution): add API Co-authored-by: @AntoineChambert-Loir --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory 57/5 Mathlib/RingTheory/PowerSeries/Basic.lean,Mathlib/RingTheory/PowerSeries/Substitution.lean 2 13 ['Ruben-VandeVelde', 'github-actions', 'mariainesdff', 'mattrobball'] mattrobball
assignee:mattrobball
21-24972
21 days ago
21-24972
21 days ago
68-44993
68 days
25831 ScottCarnahan
author:ScottCarnahan
feat (RingTheory/HahnSeries): Powers of a binomial This PR introduces powers of a binomial `single g 1 - single g' 1` in a Hahn series, where the powers take values in a binomial ring. These series behave as one would expect with respect to addition of powers, and comparison with natural number powers. They are often used in the theory of vertex algebras. --- - [x] depends on: #25830 - [x] depends on: #27497 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) --- *This PR continues the work from #24102.* *Original PR: https://github.com/leanprover-community/mathlib4/pull/24102* t-ring-theory 132/0 Mathlib.lean,Mathlib/RingTheory/HahnSeries/Addition.lean,Mathlib/RingTheory/HahnSeries/Binomial.lean,Mathlib/RingTheory/HahnSeries/HEval.lean,Mathlib/RingTheory/HahnSeries/Multiplication.lean 5 13 ['ScottCarnahan', 'github-actions', 'kbuzzard', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] kbuzzard
assignee:kbuzzard
20-84560
20 days ago
55-71951
1 month ago
55-73406
55 days
29761 bwangpj
author:bwangpj
feat: Chinese Remainder Theorem for `ZMod n` Define `ZMod.equivPi`, the Chinese Remainder Theorem for `ZMod n`, decomposing it as a product of `ZMod` over its prime power factors. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data 22/0 Mathlib/Data/Nat/Factorization/Basic.lean,Mathlib/Data/ZMod/QuotientRing.lean 2 8 ['Ruben-VandeVelde', 'bwangpj', 'github-actions', 'j-loreaux'] nobody
20-71161
20 days ago
20-71161
20 days ago
21-36145
21 days
26096 vasnesterov
author:vasnesterov
feat(Topology/Instances): Cantor set is the set of ternary numbers without `1`s * Prove `ofDigits_zero_two_sequence_mem_cantorSet`: If `x = 0.d₀d₁...` in base-3, and none of the digits `dᵢ` is `1`, then `x` belongs to the Cantor set. * Prove `ofDigits_zero_two_sequence_unique`: such a representation is uniquie. * Define `toTernary` which converts a real number from the Cantor set to its ternary representation without `1`s. * Prove `ofDigits_cantorToTernary : ofDigits (cantorToTernary x) = x`. --- This is a prerequisite for #26136. - [x] depends on: #26001 - [x] depends on: #26021 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) large-import t-topology 231/0 Mathlib/Topology/Instances/CantorSet.lean,scripts/noshake.json 2 3 ['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot'] jcommelin
assignee:jcommelin
20-62496
20 days ago
27-75035
27 days ago
27-75391
27 days
29530 ShreckYe
author:ShreckYe
feat(Dynamics/PeriodicPts): some theorems for `Pi.map` in `Dynamics/PeriodicPts` analogous to those for `Prod.map` Split from #29204. Some namespace prefixes are added in `GroupTheory/OrderOfElement.lean` to distinguish the extra imports introduced. - [ ] depends on: #29528 large-import 77/8 Mathlib/Dynamics/PeriodicPts/Defs.lean,Mathlib/Dynamics/PeriodicPts/Lemmas.lean,Mathlib/GroupTheory/OrderOfElement.lean 3 2 ['github-actions', 'mathlib4-dependent-issues-bot'] dupuisf
assignee:dupuisf
20-62490
20 days ago
28-1923
28 days ago
28-2576
28 days
29569 chrisflav
author:chrisflav
chore(RingTheory/LocalProperties): add algebra versions of exactness lemmas The module variants are less convenient to apply directly in the case of algebras. From Pi1. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory 67/0 Mathlib/RingTheory/LocalProperties/Exactness.lean 1 1 ['github-actions'] mattrobball
assignee:mattrobball
20-62485
20 days ago
27-68804
27 days ago
27-68923
27 days
27306 xyzw12345
author:xyzw12345
feat: `lie_ring` tactic and `LieReduce` command This PR continues the work from #22196. Original PR: https://github.com/leanprover-community/mathlib4/pull/22196 t-meta 810/2 Mathlib.lean,Mathlib/Algebra/Lie/Derivation/AdjointAction.lean,Mathlib/Tactic.lean,Mathlib/Tactic/LieAlgebra/Basic.lean,Mathlib/Tactic/LieAlgebra/LieRingNF.lean,Mathlib/Util/AtomM.lean,MathlibTest/lie_ring.lean,scripts/noshake.json 8 12 ['JovanGerb', 'github-actions', 'xyzw12345'] JovanGerb
assignee:JovanGerb
20-48504
20 days ago
30-53093
1 month ago
78-20171
78 days
26829 pechersky
author:pechersky
feat(RingTheory/Valuation): Valuation.leAddSubgroup and ideal/submodule versions of ltAddSubgroup Extracted from #25450 without changing how Valued works --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) @faenuccio hopefully this bypasses any wait on #14752 because I am not changing Valued files. t-ring-theory 173/0 Mathlib/RingTheory/Valuation/Basic.lean,Mathlib/RingTheory/Valuation/Integers.lean 2 7 ['JovanGerb', 'github-actions', 'mariainesdff', 'mathlib4-merge-conflict-bot', 'pechersky'] mariainesdff
assignee:mariainesdff
20-8050
20 days ago
61-84836
2 months ago
94-59348
94 days
29400 ShreckYe
author:ShreckYe
feat(`Algebra/BigOperators`): products of the results of insertion and removal on tuples and lists, and some needed lemmas large-import 102/0 Mathlib.lean,Mathlib/Algebra/BigOperators/Fin.lean,Mathlib/Algebra/BigOperators/Group/List/Basic.lean,Mathlib/Algebra/BigOperators/Group/List/Defs.lean,Mathlib/Algebra/BigOperators/Group/Vector/Basic.lean,Mathlib/Data/Fin/Tuple/Basic.lean 6 6 ['ShreckYe', 'bryangingechen', 'eric-wieser', 'github-actions'] bryangingechen
assignee:bryangingechen
19-74334
19 days ago
32-23886
1 month ago
32-23929
32 days
27429 smorel394
author:smorel394
feat(RepresentationTheory/FinGroupCharZero): applications of Maschke's theorem Prove some properties of representations that follow from Maschke's theorem: * If `G` is a finite group whose order is invertible in a field `k`, then every object of `Rep k G` (resp. `FDRep k G`) is injective and projective. * For an object `V` of `FDRep k G`, when `k` is an algebraically closed field in which the order of `G` is invertible: (1) `V` is simple if and only `V ⟶ V` is a `k`-vector space of dimension `1` (`FDRep.simple_iff_end_is_rank_one`); (2) When `k` is characteristic zero, `V` is simple if and only if `∑ g : G, V.character g * V.character g⁻¹ = Fintype.card G` (`FDRep.simple_iff_char_is_norm_one`). Note: This used to be #27165, but it was closed for some reason I don't understand. - [x] depends on: #27154 - [x] depends on: #27134 - [x] depends on: #27125 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
135/0 Mathlib.lean,Mathlib/RepresentationTheory/FinGroupCharZero.lean 2 4 ['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] jcommelin
assignee:jcommelin
19-62507
19 days ago
27-8244
27 days ago
27-8595
27 days
29562 ShreckYe
author:ShreckYe
feat(Analysis/SpecialFunctions/Trigonometric): tangent half-angle substitution t-analysis 82/0 Mathlib/Analysis/SpecialFunctions/Trigonometric/Complex.lean 1 1 ['github-actions'] urkud
assignee:urkud
19-62502
19 days ago
28-7344
28 days ago
28-7384
28 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 69/1 Mathlib/Topology/Algebra/Module/ClosedSubmodule.lean 1 2 ['github-actions', 'mathlib4-dependent-issues-bot'] fpvandoorn
assignee:fpvandoorn
18-72236
18 days ago
27-5650
27 days ago
27-7936
27 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 1 ['github-actions'] nobody
17-18567
17 days ago
22-25100
22 days ago
22-25146
22 days
22151 alreadydone
author:alreadydone
feat(RingTheory): a semiprimary ring is Noetherian/Artinian iff its Jacobson radical is fg A key fact used is `Module.FG.smul`: if `I` is a two-sided ideal of `R` that is f.g. as a left ideal and `N` is a f.g. `R`-module, then `I • M` is also a f.g. `R`-module. Many lemmas about coprimality of ideals are also generalized to the noncommutative, two-sided setting. --- - [x] depends on: #21904 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory 233/166 Mathlib/Algebra/Algebra/Operations.lean,Mathlib/AlgebraicGeometry/EllipticCurve/Affine/Point.lean,Mathlib/NumberTheory/RamificationInertia/Basic.lean,Mathlib/RingTheory/Extension/Basic.lean,Mathlib/RingTheory/Finiteness/Basic.lean,Mathlib/RingTheory/Finiteness/Ideal.lean,Mathlib/RingTheory/HopkinsLevitzki.lean,Mathlib/RingTheory/Ideal/Maps.lean,Mathlib/RingTheory/Ideal/Operations.lean 9 10 ['alreadydone', 'github-actions', 'leanprover-bot', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] eric-wieser
assignee:eric-wieser
16-79838
16 days ago
16-79904
16 days ago
196-78959
196 days
29497 xyzw12345
author:xyzw12345
feat(Counterexamples): A ring such that dim A = 1 but dim A[x] = 3 In this PR, we constructed an example of a commutative ring `A` that satisfies `ringKrullDim A = 1` but `ringKrullDim A[X] = 3`, following the construction of https://math.stackexchange.com/questions/1267419/examples-of-rings-whose-polynomial-rings-have-large-dimension --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
176/0 Counterexamples.lean,Counterexamples/DimensionPolynomial.lean,Mathlib.lean,Mathlib/Algebra/Ring/Subring/Basic.lean,Mathlib/FieldTheory/RatFunc/AsPolynomial.lean,Mathlib/RingTheory/KrullDimension/LocalRing.lean,Mathlib/RingTheory/LocalRing/MaximalIdeal/Basic.lean 7 15 ['github-actions', 'joelriou', 'kbuzzard', 'kckennylau', 'kim-em', 'xyzw12345'] joelriou
assignee:joelriou
16-64826
16 days ago
16-64826
16 days ago
28-8628
28 days
29626 themathqueen
author:themathqueen
chore(Algebra/Order/Module/PositiveLinearMap): generalize `OrderHomClass.ofLinear` Generalize `OrderHomClass.ofLinear` from linear maps to additive group homomorphisms. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra easy
label:t-algebra$
10/11 Mathlib/Algebra/Order/Module/PositiveLinearMap.lean,Mathlib/Analysis/CStarAlgebra/CompletelyPositiveMap.lean 2 5 ['Ruben-VandeVelde', 'github-actions', 'themathqueen'] Vierkantor
assignee:Vierkantor
16-62500
16 days ago
24-15659
24 days ago
25-80412
25 days
29688 tb65536
author:tb65536
feat(FieldTheory/IsGaloisGroup): prove the Galois correspondence for `IsGaloisGroup` This PR reproves the Galois correspondence for `IsGaloisGroup`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
89/0 Mathlib/FieldTheory/Galois/IsGaloisGroup.lean 1 1 ['github-actions'] joneugster
assignee:joneugster
16-62496
16 days ago
23-77212
23 days ago
23-77190
23 days
25799 dagurtomas
author:dagurtomas
feat(CategoryTheory): the universal property of localized monoidal categories This PR provides a monoidal structure on any functor out of a localized monoidal category whose precomposition with the localization functor is monoidal --- - [x] depends on: #29564 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) --- *This PR continues the work from #24727.* *Original PR: https://github.com/leanprover-community/mathlib4/pull/24727* file-removed t-category-theory 244/2 Mathlib.lean,Mathlib/CategoryTheory/Localization/Bifunctor.lean,Mathlib/CategoryTheory/Localization/Monoidal/Basic.lean,Mathlib/CategoryTheory/Localization/Monoidal/Functor.lean,Mathlib/CategoryTheory/Monoidal/Functor.lean,Mathlib/CategoryTheory/Monoidal/Multifunctor.lean,Mathlib/CategoryTheory/Monoidal/NaturalTransformation.lean,Mathlib/CategoryTheory/Sites/Monoidal.lean 8 20 ['dagurtomas', 'github-actions', 'joelriou', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] TwoFX
assignee:TwoFX
16-1840
16 days ago
16-4867
16 days ago
30-80941
30 days
29624 mcdoll
author:mcdoll
feat(LinearAlgebra/LinearPMap): add definition of resolvent and first resolvent identity --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
180/2 Mathlib/LinearAlgebra/LinearPMap.lean 1 2 ['github-actions', 'mcdoll'] kim-em
assignee:kim-em
15-76264
15 days ago
24-815
24 days ago
24-793
24 days
27887 JovanGerb
author:JovanGerb
feat: `to_dual` attribute This PR defines the `to_dual` attribute for translating lemmas to their dual. This is useful in order theory and in category theory. It is built on top of the `to_additive` machinery. This PR only adds `@[to_dual]` tags in files that directly need to import `ToDual`, namely `Order/Defs/PartialOrder`, `Order/Notation` and `Combinatorics/Quiver/Basic`. Further tagging is left for (many) future PRs. This PR continues the work from #21719 Related (mathlib3) issues: - https://github.com/leanprover-community/mathlib3/issues/13461 - https://github.com/leanprover-community/mathlib3/issues/7691 Co-authored-by: @bryangingechen --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) large-import t-meta 597/276 Mathlib.lean,Mathlib/Combinatorics/Quiver/Basic.lean,Mathlib/GroupTheory/Coset/Defs.lean,Mathlib/GroupTheory/FreeGroup/Basic.lean,Mathlib/GroupTheory/MonoidLocalization/Basic.lean,Mathlib/Order/Basic.lean,Mathlib/Order/Defs/PartialOrder.lean,Mathlib/Order/Notation.lean,Mathlib/Tactic.lean,Mathlib/Tactic/ToAdditive/Frontend.lean,Mathlib/Tactic/ToAdditive/GuessName.lean,Mathlib/Tactic/ToAdditive/ToDual.lean,Mathlib/Tactic/ToDual.lean,MathlibTest/toAdditive.lean,scripts/noshake.json 15 13 ['JovanGerb', 'bryangingechen', 'github-actions', 'mathlib4-merge-conflict-bot'] alexjbest
assignee:alexjbest
15-70118
15 days ago
15-70855
15 days ago
41-15025
41 days
29715 ADedecker
author:ADedecker
feat: generalize `IsClosed.vadd_right_of_isCompact` to proper actions I realized a few weeks after adding them to Mathlib that the more conceptual approach for lemmas of the form "`s • t` is closed when one of `s` and `t` is closed and the other is compact" is that of proper maps and proper actions. This PR switches to this approach. More precisely: - I refactored the proof [IsClosed.smul_left_of_isCompact](https://leanprover-community.github.io/mathlib4_docs/Mathlib/Topology/Algebra/Group/Pointwise.html#IsClosed.smul_left_of_isCompact) in terms of properness. The proof is essentially the same length, but conceptually simpler. - More importantly, I generalize [IsClosed.vadd_right_of_isCompact](https://leanprover-community.github.io/mathlib4_docs/Mathlib/Topology/Algebra/Group/AddTorsor.html#IsClosed.vadd_right_of_isCompact) from topological torsors to proper actions. Note that I do not assume separation, which creates some troubles as compact sets are not closed... - To support the above, I introduce a bit more API on proper maps - I also moved `isProperMap_iff_isClosedMap_filter` to `Topology/Maps/Proper/UniversallyClosed`, together with the ultrafilter analog. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) large-import t-topology 196/93 Mathlib/Topology/Algebra/Group/AddTorsor.lean,Mathlib/Topology/Algebra/Group/Pointwise.lean,Mathlib/Topology/Algebra/ProperAction/Basic.lean,Mathlib/Topology/Algebra/ProperAction/ProperlyDiscontinuous.lean,Mathlib/Topology/LocalAtTarget.lean,Mathlib/Topology/Maps/Proper/Basic.lean,Mathlib/Topology/Maps/Proper/UniversallyClosed.lean 7 2 ['ADedecker', 'github-actions'] grunweg
assignee:grunweg
15-62494
15 days ago
23-22111
23 days ago
23-22150
23 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 1310/0 Archive.lean,Archive/Imo/Imo2025Q1.lean 2 2 ['github-actions', 'mathlib4-merge-conflict-bot'] dwrensha
assignee:dwrensha
15-25618
15 days ago
20-45090
20 days ago
52-70196
52 days
27244 xroblot
author:xroblot
feat(RingTheory/DedekindDomain): lifting an ideal in an extension is injective This PR develops some API for [FractionalIdeal.extendedHomₐ](https://leanprover-community.github.io/mathlib4_docs/Mathlib/RingTheory/FractionalIdeal/Extended.html#FractionalIdeal.extendedHom%E2%82%90) and in particular proves when it is an injective map. As a consequence, it deduces the fact that lifting an integral ideal in an extension of Dedekind domains is an injective map. Note: the import increase happens in a leaf file `Mathlib.RingTheory.FractionalIdeal.Extended` --- - [x] depends on: #28800 t-ring-theory large-import 140/8 Mathlib/RingTheory/DedekindDomain/Ideal/Lemmas.lean,Mathlib/RingTheory/FractionalIdeal/Extended.lean,Mathlib/RingTheory/Localization/Basic.lean 3 5 ['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'xroblot'] kbuzzard
assignee:kbuzzard
15-22043
15 days ago
36-19011
1 month ago
72-23593
72 days
26396 xroblot
author:xroblot
feat(RingTheory): define the dual of a basis for the trace and prove basic properties Specialize the construction of `BilinForm.dualBasis` to the case of the trace and proves basic results about it. This will be useful for future works on the [Submodule.traceDual](https://leanprover-community.github.io/mathlib4_docs/Mathlib/RingTheory/DedekindDomain/Different.html#Submodule.traceDual) --- t-ring-theory 121/38 Mathlib/LinearAlgebra/BilinearForm/Properties.lean,Mathlib/RingTheory/DedekindDomain/Different.lean,Mathlib/RingTheory/Trace/Basic.lean 3 3 ['github-actions', 'mathlib4-merge-conflict-bot'] adomani
assignee:adomani
15-21815
15 days ago
24-15117
24 days ago
104-69139
104 days
26155 xroblot
author:xroblot
feat(DedekindDomain/Different): add the transitivity formula This PR proves the transitivity formula for the different ideal. The PR also adds one new instance: - `FiniteDimensional (FractionRing A) (FractionRing B)` deduced from `Module.Finite A B` when `B` is a Dedekind domain. --- t-algebra
label:t-algebra$
177/10 Mathlib/RingTheory/DedekindDomain/Different.lean,Mathlib/RingTheory/DedekindDomain/IntegralClosure.lean,Mathlib/RingTheory/FractionalIdeal/Extended.lean,Mathlib/RingTheory/Localization/Basic.lean 4 15 ['erdOne', 'github-actions', 'mathlib4-merge-conflict-bot', 'xroblot'] Vierkantor
assignee:Vierkantor
15-21779
15 days ago
35-37356
1 month ago
107-44204
107 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 62/0 Mathlib.lean,Mathlib/Combinatorics/Digraph/Orientation.lean,Mathlib/Combinatorics/Digraph/Tournament.lean 3 5 ['JaafarTanoukhi', 'NotWearingPants', 'Rida-Hamadani', 'github-actions'] kmill
assignee:kmill
15-5751
15 days ago
45-82388
1 month ago
45-82422
45 days
28967 utkuokur
author:utkuokur
refactor(Combinatorics/SimpleGraph/Walk): simplify proof of "support_tail_of_not_nil" The proof of the lemma named "support_tail_of_not_nil" is shortened. Since "support_tail" is not needed anymore, it is removed. @[deprecated (since := "2025-08-26")] sign is added for the removed "support_tail". The library references to "support_tail" are replaced with "support_tail_of_not_nil". To keep [@simp] on "cons_support_tail" and avoid the linter error, the [@simp] of "support_tail_of_not_nil" (previously on "support_tail") is removed. There might be a better way that I am missing, to deal with the linter error. --- Additionally, a merge conflict with `master` was resolved by keeping the generalized `support_tail_of_not_nil` and reintroducing `support_tail` as a deprecated alias for compatibility. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-combinatorics 7/10 Mathlib/Combinatorics/SimpleGraph/Hamiltonian.lean,Mathlib/Combinatorics/SimpleGraph/Walk.lean 2 3 ['github-actions', 'mathlib4-merge-conflict-bot', 'themathqueen'] awainverse
assignee:awainverse
14-83465
14 days ago
30-77637
1 month ago
44-7149
44 days
27307 xyzw12345
author:xyzw12345
feat(RingTheory/GradedAlgebra): homogeneous relation This PR continues the work from #22279. Original PR: https://github.com/leanprover-community/mathlib4/pull/22279 t-ring-theory 391/0 Mathlib.lean,Mathlib/Algebra/Algebra/Equiv.lean,Mathlib/Algebra/DirectSum/Basic.lean,Mathlib/Algebra/DirectSum/Module.lean,Mathlib/Algebra/Module/LinearMap/Defs.lean,Mathlib/Algebra/Ring/Equiv.lean,Mathlib/Algebra/RingQuot.lean,Mathlib/RingTheory/GradedAlgebra/Basic.lean,Mathlib/RingTheory/GradedAlgebra/HomogeneousRelation.lean 9 9 ['chrisflav', 'eric-wieser', 'github-actions', 'ocfnash', 'xyzw12345'] mattrobball
assignee:mattrobball
14-62498
14 days ago
66-2485
2 months ago
81-13801
81 days
29596 alreadydone
author:alreadydone
chore(Algebra): extract `Submonoid.IsLocalizationMap` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
282/119 Mathlib.lean,Mathlib/Algebra/Module/LocalizedModule/IsLocalization.lean,Mathlib/GroupTheory/MonoidLocalization/Basic.lean,Mathlib/GroupTheory/MonoidLocalization/Lemmas.lean,Mathlib/GroupTheory/MonoidLocalization/MonoidWithZero.lean,Mathlib/RingTheory/Extension/Presentation/Submersive.lean,Mathlib/RingTheory/Localization/Defs.lean 7 3 ['github-actions', 'mathlib4-merge-conflict-bot'] kim-em
assignee:kim-em
14-62494
14 days ago
22-16051
22 days ago
26-28973
26 days
29723 Ruben-VandeVelde
author:Ruben-VandeVelde
feat: add TensorProduct.piScalarRight_symm_algebraMap --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) FLT t-algebra
label:t-algebra$
5/0 Mathlib/LinearAlgebra/TensorProduct/Pi.lean 1 3 ['Ruben-VandeVelde', 'github-actions', 'themathqueen'] joneugster
assignee:joneugster
14-62491
14 days ago
23-9988
23 days ago
23-10023
23 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 476/0 Mathlib.lean,Mathlib/Combinatorics/Digraph/Maps.lean 2 1 ['github-actions'] nobody
14-32930
14 days ago
15-6033
15 days ago
15-6073
15 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 97/0 Mathlib/GroupTheory/DoubleCoset.lean 1 16 ['Ruben-VandeVelde', 'WilliamCoram', 'github-actions', 'mathlib4-merge-conflict-bot'] mariainesdff
assignee:mariainesdff
14-27131
14 days ago
21-2776
21 days ago
79-68652
79 days
26259 Raph-DG
author:Raph-DG
feat(Topology): Connecting different notions of locally finite In this PR we connect the notions of local finiteness of an indexed family of sets (as in LocallyFinite) and of a set of sets (as in Function.locallyFinsuppWithin) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) maintainer-merge t-topology 38/0 Mathlib/Topology/LocallyFinsupp.lean 1 18 ['Raph-DG', 'chrisflav', 'github-actions', 'jcommelin', 'kckennylau'] jcommelin
assignee:jcommelin
14-6773
14 days ago
14-32089
14 days ago
102-82478
102 days
29411 llllvvuu
author:llllvvuu
feat(LinearAlgebra/Matrix/Rank): rank factorization The rank factorization derived from `Module.finBasis`. Co-authored-by: Aristotle Harmonic --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
20/0 Mathlib/LinearAlgebra/Matrix/Rank.lean,Mathlib/LinearAlgebra/Matrix/ToLin.lean 2 1 ['github-actions'] jcommelin
assignee:jcommelin
14-5805
14 days ago
31-75133
1 month ago
31-75126
31 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 35/0 Mathlib/Data/Multiset/Fintype.lean 1 8 ['Ruben-VandeVelde', 'github-actions', 'llllvvuu', 'vihdzp', 'wwylele'] nobody
14-5473
14 days ago
28-60903
28 days ago
28-60897
28 days
29488 Timeroot
author:Timeroot
feat: 'said' tactic Functionally similar to `says`, but explicitly not for checking output or even saying there ever was output. `X said Y` just means that `X` was part of the process for (a human, or machine, or both) to generate `Y`. Based on this [#mathlib4 > noisy simp says in CI @ 💬](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/noisy.20simp.20says.20in.20CI/near/538443152) Zulip discussion --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-meta 40/0 Mathlib/Tactic/Linter/UnusedTactic.lean,Mathlib/Tactic/Linter/UnusedTacticExtension.lean,Mathlib/Tactic/Says.lean,MathlibTest/says.lean 4 3 ['JovanGerb', 'MichaelStollBayreuth', 'github-actions'] JovanGerb
assignee:JovanGerb
13-62495
13 days ago
21-34469
21 days ago
29-54017
29 days
29765 YaelDillies
author:YaelDillies
feat: commutative monoids are internal monoids From Toric --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) toric t-category-theory 76/6 Mathlib/CategoryTheory/Monoidal/Cartesian/Grp_.lean,Mathlib/CategoryTheory/Monoidal/Cartesian/Mon_.lean 2 3 ['YaelDillies', 'eric-wieser', 'github-actions'] kim-em
assignee:kim-em
13-62491
13 days ago
21-39054
21 days ago
21-39088
21 days
29769 Vierkantor
author:Vierkantor
CI: run a weekly linter workflow This PR adds a workflow analogous to the nightly regression lints, that reports possible refactors using the tactic analysis framework. Those would be too noisy or take too much time to run in regular CI. As a first linter, we have the `mergeWithGrind` linter that reports when a sequence of tactics followed by `grind` can become just `grind`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) CI 102/1 .github/workflows/weekly-lints.yml,Mathlib/Init.lean 2 1 ['github-actions'] bryangingechen
assignee:bryangingechen
13-62490
13 days ago
21-26999
21 days ago
21-26977
21 days
29771 Vierkantor
author:Vierkantor
refactor(TacticAnalysis): use full CommandElabM context in test Running the `rwMerge` linter on the whole of Mathlib reveals that the tactic analysis framework did not always correctly pass the environment to the test step of a pass. By running the test in a full `CommandElabM` and adding a `ContextInfo` and `TacticInfo`, we can access the right environment (using the `ctxI.runTacticCode` function). There are still a few subtle issues to do with notation but I would like to get this fix in first, since it involves some larger refactors. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-meta 44/17 Mathlib/Tactic/TacticAnalysis.lean,Mathlib/Tactic/TacticAnalysis/Declarations.lean,MathlibTest/TacticAnalysis.lean 3 7 ['adomani', 'bryangingechen', 'github-actions', 'leanprover-bot', 'leanprover-community-mathlib4-bot'] kim-em
assignee:kim-em
13-62489
13 days ago
21-10015
21 days ago
21-26544
21 days
29471 harahu
author:harahu
doc: use en dash instead of hyphen in Akra-Bazzi When joining two names, like is done here, the en dash is usually preferred over a regular hyphen. This also aligns the naming in mathlib with that of [Wikipedia](https://en.wikipedia.org/wiki/Akra%E2%80%93Bazzi_method). Some concern was raised [on Zulip](https://leanprover.zulipchat.com/#narrow/channel/144837-PR-reviews/topic/.23.2029464.20corrections.20to.20docs.20by.20way.20of.20LLM/near/538466767) regarding what this implies for code searches using `grep` and similar tools. Consequently, tags have been added to make sure searches using the regular hyphen will still hit the relevant files. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-computability 28/21 Mathlib/Computability/AkraBazzi/AkraBazzi.lean,Mathlib/Computability/AkraBazzi/GrowsPolynomially.lean,Mathlib/Computability/AkraBazzi/SumTransform.lean 3 6 ['github-actions', 'mathlib4-merge-conflict-bot'] nobody
13-42378
13 days ago
13-42403
13 days ago
29-58341
29 days
23920 YaelDillies
author:YaelDillies
feat: relation-separated sets Define a notion of separation of a set relative to a relation. This will be used to unify metric and dynamical separation. From MiscYD and LeanAPAP --- - [x] depends on: #26988 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data 66/0 Mathlib.lean,Mathlib/Data/Rel/Separated.lean 2 21 ['ADedecker', 'D-Thomine', 'YaelDillies', 'b-mehta', 'github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] ADedecker
assignee:ADedecker
13-7787
13 days ago
13-7809
13 days ago
43-71737
43 days
29354 themathqueen
author:themathqueen
refactor(Algebra/Algebra/Equiv): allow for non-unital `AlgEquiv` This refactors `AlgEquiv` to allow for non-unital algebras. More specifically, we weaken the type class assumptions from: ```lean structure AlgEquiv (R A B : Type*) [CommSemiring R] [Semiring A] [Semiring B] [Algebra R A] [Algebra R B] ``` to ```lean structure AlgEquiv (R A B : Type*) [Add A] [Add B] [Mul A] [Mul B] [SMul R A] [SMul R B] ``` Instead of a `commutes'` field, we now have a `map_smul'` field. We also include a definition `AlgEquiv.ofCommutes` which takes in a `RingEquiv` and a `commutes'` field to match before and for convenience. `StarAlgEquiv` now extends `AlgEquiv`. We also generalize a few files to allow for non-unital. I suspect there are a few more things to generalize, but will leave this for later. Co-authored-by: Jireh Loreaux --- Revives #8686. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
527/484 Mathlib/Algebra/Algebra/Equiv.lean,Mathlib/Algebra/Algebra/Opposite.lean,Mathlib/Algebra/Algebra/Pi.lean,Mathlib/Algebra/Algebra/Prod.lean,Mathlib/Algebra/Algebra/Subalgebra/Basic.lean,Mathlib/Algebra/Algebra/Subalgebra/MulOpposite.lean,Mathlib/Algebra/Algebra/Tower.lean,Mathlib/Algebra/Algebra/TransferInstance.lean,Mathlib/Algebra/Category/AlgCat/Basic.lean,Mathlib/Algebra/Category/CommAlgCat/Basic.lean,Mathlib/Algebra/Category/CommAlgCat/FiniteType.lean,Mathlib/Algebra/Category/Ring/Constructions.lean,Mathlib/Algebra/DualQuaternion.lean,Mathlib/Algebra/MonoidAlgebra/Basic.lean,Mathlib/Algebra/MonoidAlgebra/ToDirectSum.lean,Mathlib/Algebra/MvPolynomial/Equiv.lean,Mathlib/Algebra/MvPolynomial/Rename.lean,Mathlib/Algebra/Polynomial/AlgebraMap.lean,Mathlib/Algebra/Polynomial/Taylor.lean,Mathlib/Algebra/Quaternion.lean,Mathlib/Algebra/Star/Free.lean,Mathlib/Algebra/Star/StarAlgHom.lean,Mathlib/Analysis/CStarAlgebra/Spectrum.lean,Mathlib/Analysis/Normed/Algebra/GelfandFormula.lean,Mathlib/Analysis/Normed/Algebra/Spectrum.lean,Mathlib/Analysis/Normed/Algebra/UnitizationL1.lean,Mathlib/Analysis/Normed/Lp/LpEquiv.lean,Mathlib/Analysis/Normed/Module/Basic.lean,Mathlib/Analysis/RCLike/Basic.lean,Mathlib/Data/Matrix/Basic.lean,Mathlib/Data/Matrix/Composition.lean,Mathlib/Data/Matrix/DualNumber.lean,Mathlib/FieldTheory/Fixed.lean,Mathlib/FieldTheory/Galois/Basic.lean,Mathlib/FieldTheory/Galois/Profinite.lean,Mathlib/FieldTheory/IntermediateField/Adjoin/Basic.lean,Mathlib/FieldTheory/IntermediateField/Basic.lean,Mathlib/FieldTheory/Normal/Basic.lean,Mathlib/FieldTheory/PrimitiveElement.lean,Mathlib/FieldTheory/RatFunc/Basic.lean,Mathlib/FieldTheory/Separable.lean,Mathlib/LinearAlgebra/CliffordAlgebra/BaseChange.lean,Mathlib/LinearAlgebra/CliffordAlgebra/Conjugation.lean,Mathlib/LinearAlgebra/Complex/Module.lean,Mathlib/LinearAlgebra/Matrix/Basis.lean,Mathlib/LinearAlgebra/Matrix/Charpoly/Coeff.lean,Mathlib/LinearAlgebra/Matrix/Charpoly/LinearMap.lean,Mathlib/LinearAlgebra/Matrix/Reindex.lean,Mathlib/LinearAlgebra/Matrix/ToLin.lean,Mathlib/LinearAlgebra/Matrix/Unique.lean,Mathlib/LinearAlgebra/TensorProduct/Graded/Internal.lean,Mathlib/LinearAlgebra/TensorProduct/Subalgebra.lean,Mathlib/NumberTheory/NumberField/Discriminant/Defs.lean,Mathlib/RingTheory/AdjoinRoot.lean,Mathlib/RingTheory/Bialgebra/Equiv.lean,Mathlib/RingTheory/DedekindDomain/Different.lean,Mathlib/RingTheory/Etale/Field.lean,Mathlib/RingTheory/Finiteness/Basic.lean,Mathlib/RingTheory/Flat/Equalizer.lean,Mathlib/RingTheory/FractionalIdeal/Operations.lean,Mathlib/RingTheory/Frobenius.lean,Mathlib/RingTheory/GradedAlgebra/Basic.lean,Mathlib/RingTheory/HahnSeries/PowerSeries.lean,Mathlib/RingTheory/Ideal/Operations.lean,Mathlib/RingTheory/Ideal/Over.lean,Mathlib/RingTheory/Ideal/Quotient/Operations.lean,Mathlib/RingTheory/IntegralClosure/IntegrallyClosed.lean,Mathlib/RingTheory/Invariant/Basic.lean,Mathlib/RingTheory/Invariant/Profinite.lean,Mathlib/RingTheory/IsTensorProduct.lean,Mathlib/RingTheory/Jacobson/Artinian.lean,Mathlib/RingTheory/Jacobson/Ring.lean,Mathlib/RingTheory/Kaehler/Basic.lean,Mathlib/RingTheory/LaurentSeries.lean,Mathlib/RingTheory/Localization/Basic.lean,Mathlib/RingTheory/Localization/FractionRing.lean,Mathlib/RingTheory/MatrixAlgebra.lean,Mathlib/RingTheory/MvPolynomial/Localization.lean,Mathlib/RingTheory/Norm/Basic.lean,Mathlib/RingTheory/Polynomial/Quotient.lean,Mathlib/RingTheory/PolynomialAlgebra.lean,Mathlib/RingTheory/PowerSeries/WeierstrassPreparation.lean,Mathlib/RingTheory/RingHom/FiniteType.lean,Mathlib/RingTheory/SimpleModule/Isotypic.lean,Mathlib/RingTheory/Smooth/Basic.lean,Mathlib/RingTheory/Smooth/Pi.lean,Mathlib/RingTheory/Spectrum/Prime/Polynomial.lean,Mathlib/RingTheory/TensorProduct/Basic.lean,Mathlib/RingTheory/TensorProduct/MvPolynomial.lean,Mathlib/RingTheory/TensorProduct/Pi.lean,Mathlib/RingTheory/TensorProduct/Quotient.lean,Mathlib/RingTheory/Trace/Basic.lean,Mathlib/RingTheory/Unramified/Field.lean,Mathlib/Topology/Algebra/Algebra/Equiv.lean,Mathlib/Topology/Algebra/Module/FiniteDimension.lean,Mathlib/Topology/LocallyConstant/Algebra.lean 96 25 ['fpvandoorn', 'github-actions', 'leanprover-bot', 'leanprover-community-mathlib4-bot', 'mathlib4-merge-conflict-bot', 'themathqueen'] joelriou
assignee:joelriou
13-3873
13 days ago
13-6494
13 days ago
26-64269
26 days
29538 YaelDillies
author:YaelDillies
refactor(FractionalIdeal): use algebraic order theory API Instantiate instances earlier and use generic lemmas instead of the `FractionalIdeal`-specific ones. Also rename `_nonzero` in lemma names to `_ne_zero`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory 158/176 Mathlib/NumberTheory/NumberField/CanonicalEmbedding/Basic.lean,Mathlib/RingTheory/DedekindDomain/Different.lean,Mathlib/RingTheory/DedekindDomain/Factorization.lean,Mathlib/RingTheory/DedekindDomain/Ideal/Basic.lean,Mathlib/RingTheory/DedekindDomain/Ideal/Lemmas.lean,Mathlib/RingTheory/FractionalIdeal/Basic.lean,Mathlib/RingTheory/FractionalIdeal/Inverse.lean,Mathlib/RingTheory/FractionalIdeal/Operations.lean 8 1 ['github-actions'] chrisflav
assignee:chrisflav
11-62484
11 days ago
25-18194
25 days ago
25-18179
25 days
29791 llllvvuu
author:llllvvuu
feat(Order): lemmas about `iSupIndep` * generalize `Finset.SupIndep` "bind" operations from `DistribLattice` to `IsModularLattice` * new lemma `iSupIndep.iInf` * more characterizations of `iSupIndep` on submodules: * `iSupIndep_iff_finset_sum_eq_zero_imp_eq_zero` * `iSupIndep_iff_finset_sum_eq_imp_eq` * add `@[simp]` and `@[grind]` attributes which were helpful for these proofs Original motivation was to have the following fact: ```lean theorem iSupIndep_iInf_genEigenspace [NoZeroSMulDivisors R M] {α : Type*} (f : α → End R M) (k : ℕ∞) : iSupIndep fun μ : α → R ↦ ⨅ a : α, ((f a).genEigenspace (μ a)) k := .iInf (f · |>.genEigenspace · k) (f · |>.independent_genEigenspace k) ``` Co-authored-by: Aristotle Harmonic --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-order 166/62 Mathlib/Data/Finset/Disjoint.lean,Mathlib/Data/Finset/Lattice/Fold.lean,Mathlib/Data/Finset/Lattice/Union.lean,Mathlib/Data/Finset/Sigma.lean,Mathlib/GroupTheory/Perm/Cycle/Factors.lean,Mathlib/LinearAlgebra/DFinsupp.lean,Mathlib/LinearAlgebra/Eigenspace/Basic.lean,Mathlib/Logic/Embedding/Basic.lean,Mathlib/Order/CompactlyGenerated/Basic.lean,Mathlib/Order/Partition/Finpartition.lean,Mathlib/Order/SupIndep.lean 11 12 ['github-actions', 'leanprover-bot', 'llllvvuu'] bryangingechen
assignee:bryangingechen
11-62483
11 days ago
19-59072
19 days ago
19-82692
19 days
29512 grunweg
author:grunweg
feat: check for PR titles which do not start with "feat" etc. We ignore draft PRs and PRs with the WIP label. The set of checks is intentionally kept small, and could be expanded in the future. --- More basic version of #16303: given that mathlib's statistics will use the PR kind, let's make sure PR kinds are somewhat appropriate. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) 365/0 .github/build.in.yml,.github/workflows/bors.yml,.github/workflows/build.yml,.github/workflows/build_fork.yml,Mathlib.lean,Mathlib/Tactic.lean,Mathlib/Tactic/Linter/ValidatePRTitle.lean,lakefile.lean,scripts/README.md,scripts/check_title_labels.lean 10 17 ['bryangingechen', 'eric-wieser', 'github-actions', 'grunweg'] bryangingechen
assignee:bryangingechen
11-44020
11 days ago
29-6455
29 days ago
29-6432
29 days
28719 mitchell-horner
author:mitchell-horner
refactor: redefine `IsTuranMaximal` Redefined `IsTuranMaximal := G.IsExtremal (CliqueFree · (r + 1))` and - replaced `classical` in `IsTuranMaximal.le_iff_eq` with `DecidableRel` - refactored `turanGraph.instDecidableRelAdj`, `turanGraph_zero`, `exists_isTuranMaximal` - added `open Fintype` - replaced `simp only` with `rw` or `simp_rw` --- - [x] depends on: #28721 - [x] depends on: #29054 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-combinatorics 33/46 Mathlib/Combinatorics/SimpleGraph/Extremal/Turan.lean 1 8 ['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'mitchell-horner', 'vihdzp'] kmill
assignee:kmill
11-32765
11 days ago
11-36096
11 days ago
38-55219
38 days
25843 mitchell-horner
author:mitchell-horner
feat(Combinatorics/SimpleGraph): define `between` subgraphs The simple graph `G.between s t` is the subgraph of `G` containing edges that connect a vertex in the set `s` to a vertex in the set `t`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) --- *This PR continues the work from #24948.* *Original PR: https://github.com/leanprover-community/mathlib4/pull/24948* t-combinatorics 86/0 Mathlib/Combinatorics/SimpleGraph/Bipartite.lean 1 1 ['github-actions'] b-mehta
assignee:b-mehta
11-32741
11 days ago
118-16853
3 months ago
118-16829
118 days
29362 stepanholub
author:stepanholub
feat:(Data/List) add the notion of period of List and prove the Periodicity Lemma Add the concept of the period of a List (word, sequence) which is missing, and prove its basic nontrivial property describing under which conditions list can have two periods known as the Periodicity Lemma (aka Fine-Wilf Theorem). --- t-data new-contributor 227/0 Mathlib.lean,Mathlib/Data/List/PeriodicityLemma.lean 2 125 ['Ruben-VandeVelde', 'Timeroot', 'fpvandoorn', 'github-actions', 'madvorak', 'plp127', 'stepanholub', 'wwylele'] nobody
10-81131
10 days ago
14-83945
14 days ago
32-80142
32 days
29369 vlad902
author:vlad902
feat(SimpleGraph): `IsSubwalk` of common Walk decompositions Add some helper lemmas to show that decompositions of walks are sub-walks. t-combinatorics 61/17 Mathlib/Combinatorics/SimpleGraph/Connectivity/WalkDecomp.lean,Mathlib/Combinatorics/SimpleGraph/Walk.lean 2 1 ['github-actions'] awainverse
assignee:awainverse
10-62497
10 days ago
34-1574
1 month ago
34-1617
34 days
29121 Ruben-VandeVelde
author:Ruben-VandeVelde
feat: MvPolynomial.symmetricSubalgebra.{aevalMultiset,sumPolynomial} --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory 192/0 Mathlib.lean,Mathlib/RingTheory/MvPolynomial/Symmetric/Eval.lean 2 1 ['github-actions'] chrisflav
assignee:chrisflav
10-37035
10 days ago
40-62162
1 month ago
40-62195
40 days
29735 vihdzp
author:vihdzp
feat: order instances on quotients We define a `Preorder (Quotient s)` instance in the natural way, and prove that it can be strengthened to a `LinearOrder` when all equivalence classes are `OrdConnected`. --- See [Zulip](https://leanprover.zulipchat.com/#narrow/channel/217875-Is-there-code-for-X.3F/topic/Quotient.20of.20linear.20order.20is.20linear.20order/near/539915988) for some long-winded discussion about this. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-order 125/0 Mathlib.lean,Mathlib/Order/Quotient.lean 2 3 ['github-actions', 'plp127'] bryangingechen
assignee:bryangingechen
10-19290
10 days ago
22-46739
22 days ago
22-46774
22 days
25794 dagurtomas
author:dagurtomas
feat(CategoryTheory): localization preserves braided structure --- - [x] depends on: #29568 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) --- *This PR continues the work from #24485.* *Original PR: https://github.com/leanprover-community/mathlib4/pull/24485* file-removed t-category-theory 225/4 Mathlib.lean,Mathlib/CategoryTheory/Localization/Monoidal/Basic.lean,Mathlib/CategoryTheory/Localization/Monoidal/Braided.lean,Mathlib/CategoryTheory/Monoidal/Braided/Basic.lean,Mathlib/CategoryTheory/Monoidal/Braided/Multifunctor.lean,Mathlib/CategoryTheory/Sites/Monoidal.lean 6 15 ['dagurtomas', 'github-actions', 'joelriou', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] mattrobball
assignee:mattrobball
10-5529
10 days ago
10-6400
10 days ago
66-15551
66 days
27258 JovanGerb
author:JovanGerb
Imo2020 q6 Original PR: #23431 This PR adds a solution to IMO 2020 Q6. It follows the solution that I found when I was participating in the IMO. I used the statement formalization that was given by @jsm28. TODO: The function `project a b p` that is defined here should be replaced with `signedDist a p (b -ᵥ a)`. --- - [x] depends on: #27257 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) IMO 346/0 Archive.lean,Archive/Imo/Imo2020Q6.lean 2 2 ['github-actions', 'mathlib4-dependent-issues-bot'] dwrensha
assignee:dwrensha
9-62497
9 days ago
17-8184
17 days ago
17-9466
17 days
27416 joelriou
author:joelriou
feat(Algebra/Homology): Ext modules In this PR, we show that if `C` is a `R`-linear abelian category, then there is a `R`-module structure on the groups `Ext X Y n` for `X` and `Y` in `C` and `n : ℕ`. --- - [x] depends on: #26031 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) large-import t-algebra t-category-theory
label:t-algebra$
164/12 Mathlib.lean,Mathlib/Algebra/Homology/DerivedCategory/Ext/Basic.lean,Mathlib/Algebra/Homology/DerivedCategory/Ext/Linear.lean,Mathlib/Algebra/Homology/DerivedCategory/Linear.lean,Mathlib/CategoryTheory/Shift/ShiftedHom.lean 5 7 ['Thmoas-Guan', 'github-actions', 'joelriou', 'mathlib4-dependent-issues-bot'] dagurtomas
assignee:dagurtomas
0-24822
6 hours ago
17-8197
17 days ago
17-8318
17 days
27742 ChrisHughes24
author:ChrisHughes24
feat(Nat/nth): inequalities about Nat.nth --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data 51/0 Mathlib/Data/Nat/Nth.lean 1 3 ['ChrisHughes24', 'github-actions'] pechersky
assignee:pechersky
9-62494
9 days ago
70-26512
2 months ago
70-26550
70 days
27864 BoltonBailey
author:BoltonBailey
feat(Data/{Finset,Multiset}/Sort): give sort functions ≤ default argument Changes the `Finset.sort` and `Multiset.sort` functions to take `≤` as the default relation argument. Then removes this argument where possible through the rest of the library. This involves switching the order of arguments, but I think this is fine, as this function is mostly called by dot notation anyway, and I think it is more typical for the first argument of such functions to have the type that matches the namespace. Thanks to @eric-wieser for suggesting this approach Zulip discussion: [#mathlib4 > Redefine {Fin/Multi}set.sort to take linear order?](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Redefine.20.7BFin.2FMulti.7Dset.2Esort.20to.20take.20linear.20order.3F/with/532398325) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data 121/97 Mathlib/Algebra/Polynomial/Basic.lean,Mathlib/Data/Finset/Sort.lean,Mathlib/Data/Multiset/Sort.lean,Mathlib/Data/Nat/Nth.lean,Mathlib/GroupTheory/Perm/Cycle/Factors.lean,Mathlib/GroupTheory/Perm/Sign.lean,Mathlib/Logic/Equiv/Finset.lean,Mathlib/Logic/Equiv/Multiset.lean,Mathlib/NumberTheory/ADEInequality.lean 9 5 ['BoltonBailey', 'eric-wieser', 'github-actions', 'grunweg'] pechersky
assignee:pechersky
9-62493
9 days ago
68-10822
2 months ago
68-64354
68 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 28/0 Mathlib/Data/Rat/Lemmas.lean 1 14 ['github-actions', 'sinianluoye', 'themathqueen'] pechersky
assignee:pechersky
9-62492
9 days ago
64-62079
2 months ago
65-3725
65 days
28077 ShreckYe
author:ShreckYe
feat(Data/Finset/Card): add some more Pigeonhole Principle theorems `exists_ne_map_eq_of_card_image_lt` and `not_injOn_of_card_image_lt` `exists_ne_map_eq_of_card_image_lt` is a special case of `exists_ne_map_eq_of_card_lt_of_maps_to` where `t` is `s.image f`, and `not_injOn_of_card_image_lt` is its variant using `Set.InjOn`. I ran into some cases where such theorems would save me some time. t-data new-contributor 10/0 Mathlib/Data/Finset/Card.lean 1 4 ['ShreckYe', 'github-actions', 'themathqueen'] pechersky
assignee:pechersky
9-62491
9 days ago
63-28569
2 months ago
63-28609
63 days
28119 JasperMS
author:JasperMS
feat(Data/Set/Pairwise): prove pairwise results for Chains, move `Set.pairwise_iUnion₂` Initiate a new file `Data/Set/Pairwise/Chain.lean` which makes some `Pairwise` results available to the `IsChain` predicate. In the process, move `Set.pairwise_iUnion₂` to group it with similar results. Perform some variable harmonization. Part of Carleson, original result by Edward van de Meent. Moves: - Set.pairwise_iUnion₂: from Data.Set.Lattice to Data.Set.Pairwise.Lattice --- This PR was discussed and advice was given in [#mathlib4 > Novice questions on style and structure](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Novice.20questions.20on.20style.20and.20structure/with/533462814). Many thanks to those who helped me out! Mathlib PRs are still new to me, so please point out where I can improve! [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) carleson t-data new-contributor 56/12 Mathlib.lean,Mathlib/Data/Set/Lattice.lean,Mathlib/Data/Set/Pairwise/Chain.lean,Mathlib/Data/Set/Pairwise/Lattice.lean 4 11 ['JasperMS', 'Ruben-VandeVelde', 'edegeltje', 'github-actions'] pechersky
assignee:pechersky
9-62490
9 days ago
62-15294
2 months ago
62-15729
62 days
29351 staroperator
author:staroperator
feat(SetTheory/Cardinal): generalize and rename theorems on `Cardinal.sum` Some theorems on `Cardinal.sum f` are taking `f : ι → Cardinal.{max u v}`, which can be generalized to `f : ι → Cardinal.{v}`. Also rename `sum_le_iSup_lift`, `sum_lt_lift_of_isRegular`, `sum_eq_iSup_lift` etc. to reflect their signatures in names. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-set-theory 79/36 Mathlib/Data/W/Cardinal.lean,Mathlib/ModelTheory/Encoding.lean,Mathlib/SetTheory/Cardinal/Arithmetic.lean,Mathlib/SetTheory/Cardinal/Basic.lean,Mathlib/SetTheory/Cardinal/Cofinality.lean,Mathlib/SetTheory/Cardinal/Defs.lean,Mathlib/SetTheory/Cardinal/Order.lean,Mathlib/SetTheory/Cardinal/Ordinal.lean,Mathlib/SetTheory/Cardinal/Pigeonhole.lean,Mathlib/SetTheory/Cardinal/Regular.lean 10 5 ['github-actions', 'staroperator', 'vihdzp'] alreadydone
assignee:alreadydone
9-62488
9 days ago
34-68556
1 month ago
35-1343
35 days
29395 YaelDillies
author:YaelDillies
refactor: make `PosMulMono` and alike custom classes In the current setup, users get confusing non-beta-reduced goals involving a subtype when trying to provide an instance of `PosMulMono`. This PR changes it to be a custom structure with the expected fields. This follows `PosSMulMono` and alike. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-order t-algebra
label:t-algebra$
187/268 Counterexamples/CanonicallyOrderedCommSemiringTwoMul.lean,Mathlib/Algebra/Algebra/Operations.lean,Mathlib/Algebra/Order/GroupWithZero/Canonical.lean,Mathlib/Algebra/Order/GroupWithZero/Unbundled/Basic.lean,Mathlib/Algebra/Order/GroupWithZero/Unbundled/Defs.lean,Mathlib/Algebra/Order/GroupWithZero/WithZero.lean,Mathlib/Algebra/Order/Pi.lean,Mathlib/Algebra/Order/Ring/Canonical.lean,Mathlib/Algebra/Order/Ring/Defs.lean,Mathlib/Algebra/Order/Ring/InjSurj.lean,Mathlib/Algebra/Order/Ring/Nat.lean,Mathlib/Algebra/Order/Ring/Opposite.lean,Mathlib/Algebra/Order/Ring/Prod.lean,Mathlib/Algebra/Order/Ring/Star.lean,Mathlib/Algebra/Order/Ring/WithTop.lean,Mathlib/Data/NNRat/Defs.lean,Mathlib/Data/Num/Lemmas.lean,Mathlib/Order/Filter/FilterProduct.lean,Mathlib/Order/Filter/Ring.lean,Mathlib/SetTheory/Ordinal/Arithmetic.lean,Mathlib/SetTheory/Ordinal/NaturalOps.lean,MathlibTest/GRewrite.lean 22 4 ['github-actions', 'mathlib4-merge-conflict-bot'] Vierkantor
assignee:Vierkantor
9-62486
9 days ago
17-37715
17 days ago
27-327
27 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 37/10 Mathlib/Analysis/Calculus/Gradient/Basic.lean 1 1 ['github-actions'] hrmacbeth
assignee:hrmacbeth
9-62481
9 days ago
17-21345
17 days ago
17-21324
17 days
29888 mcdoll
author:mcdoll
feat(Analysis/Normed): Extend densely defined LinearMaps to CLM This PR both adds a new and more user-friendly way to extend a CLM defined on a dense subspace. It also moves the old definition to the same file and as a side effect, we reduce the import tree. The moved parts are not modified except for adapting the sections and imports. Original definition of `ContinuousLinearMap.extend` was by Zhouhang Zhou in 2019 (mathlib3 PR #1649) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-analysis 254/86 Mathlib.lean,Mathlib/Analysis/InnerProductSpace/LinearPMap.lean,Mathlib/Analysis/Normed/Operator/Completeness.lean,Mathlib/Analysis/Normed/Operator/Extend.lean,Mathlib/MeasureTheory/Integral/SetToL1.lean 5 2 ['github-actions', 'mcdoll'] hrmacbeth
assignee:hrmacbeth
9-62480
9 days ago
16-74948
16 days ago
17-6299
17 days
29550 Raph-DG
author:Raph-DG
feat(RingTheory): Order of vanishing in a discrete valuation ring In this PR we develop some API for working with the order of vanishing in a discrete valuation ring. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory file-removed 462/3 Mathlib.lean,Mathlib/RingTheory/DiscreteValuationRing/Basic.lean,Mathlib/RingTheory/OrderOfVanishing/Basic.lean,Mathlib/RingTheory/OrderOfVanishing/Properties.lean 4 2 ['github-actions', 'mathlib4-merge-conflict-bot'] erdOne
assignee:erdOne
9-13198
9 days ago
9-13225
9 days ago
25-25608
25 days
29341 joelriou
author:joelriou
feat(Topology): the topology generated by a family of spaces Some categories of topological spaces are "convenient" in the sense that they have nice categorical properties (e.g. they have limits, colimits and are cartesian closed). This PR is the first in a series towards showing that delta generated spaces form a cartesian closed monoidal category (see https://github.com/joelriou/topcat-model-category/blob/852a514c1d955ab586507bcd5a7b5efb99c6c3df/TopCatModelCategory/Convenient/CartesianClosed.lean#L92 for the general result), and this result is part of my formalization effort towards the Quillen model category structure on simplicial sets. In this PR, given a family `X` of topological spaces, and a topological space `Y`, we introduce the `X`-generated topology on `Y`, which is coinduced by all continuous maps `X i → Y`. (Eventually, this will generalize previous works by Dagur Asgeirsson and Ben Eltschig about compactly/delta generated spaces in mathlib. At some point, their definitions will be refactored as particular cases of the definitions in this PR series.) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-topology 291/0 Mathlib.lean,Mathlib/Topology/Convenient/GeneratedBy.lean,docs/references.bib 3 10 ['github-actions', 'joelriou', 'peabrainiac'] jcommelin
assignee:jcommelin
9-5679
9 days ago
35-31747
1 month ago
35-31723
35 days
29207 YaelDillies
author:YaelDillies
chore(MonoidAlgebra/Defs): reorder, rename variables Sort the declarations according to typeclass assumptions, *and* according to the order in which we need them to be for #25273. Rename the semiring variable to `R` and the monoid one to `M`. Simultaneously golf. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
461/588 Mathlib/Algebra/Category/Ring/Adjunctions.lean,Mathlib/Algebra/MonoidAlgebra/Basic.lean,Mathlib/Algebra/MonoidAlgebra/Defs.lean,Mathlib/Algebra/MonoidAlgebra/Division.lean,Mathlib/Algebra/MonoidAlgebra/Grading.lean,Mathlib/Algebra/MonoidAlgebra/MapDomain.lean,Mathlib/Algebra/MonoidAlgebra/Module.lean,Mathlib/Algebra/MvPolynomial/Basic.lean,Mathlib/Algebra/Polynomial/Laurent.lean 9 6 ['JovanGerb', 'YaelDillies', 'github-actions'] dagurtomas
assignee:dagurtomas
8-62479
8 days ago
16-5425
16 days ago
16-5408
16 days
29729 Ruben-VandeVelde
author:Ruben-VandeVelde
feat: Ideal.ramificationIdx_mul_inertiaDeg_of_isLocalRing --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) FLT t-number-theory 27/0 Mathlib/NumberTheory/RamificationInertia/Basic.lean,Mathlib/RingTheory/DedekindDomain/Basic.lean,Mathlib/RingTheory/DedekindDomain/Ideal/Lemmas.lean 3 8 ['Ruben-VandeVelde', 'github-actions', 'mathlib4-merge-conflict-bot', 'tb65536', 'xroblot'] MichaelStollBayreuth
assignee:MichaelStollBayreuth
8-62478
8 days ago
16-39548
16 days ago
22-33479
22 days
29772 ScottCarnahan
author:ScottCarnahan
feat (RingTheory/HahnSeries/Multiplication): Add group instances to HahnModule This PR adds `Zero` and `AddCommGroup` instances to `HahnModule` when appropriate. We also add comparison lemmas for subtraction in the `AddCommGroup` case, and reorganize some `variables`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory 18/9 Mathlib/RingTheory/HahnSeries/Multiplication.lean 1 1 ['github-actions'] erdOne
assignee:erdOne
8-62477
8 days ago
21-24263
21 days ago
21-24298
21 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 93/69 .github/workflows/daily.yml,.github/workflows/nightly-docgen.yml,.github/workflows/nightly-regression-report.yml,scripts/zulip_build_report.sh 4 1 ['github-actions'] robertylewis
assignee:robertylewis
8-62473
8 days ago
16-13848
16 days ago
16-13827
16 days
29253 FernandoChu
author:FernandoChu
feat(CategoryTheory): (Co)limits in preorders Characterize (co)limits in preorders as glbs/lubs, plus some other instances. new-contributor t-category-theory 151/13 Mathlib/CategoryTheory/Discrete/Basic.lean,Mathlib/CategoryTheory/Limits/Preorder.lean 2 12 ['FernandoChu', 'github-actions', 'joelriou'] joelriou
assignee:joelriou
8-33782
8 days ago
8-33786
8 days ago
35-32422
35 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 174/5 Mathlib/Topology/Compactness/CompactlyCoherentSpace.lean 1 4 ['github-actions', 'joelriou', 'scholzhannah'] ADedecker
assignee:ADedecker
8-32730
8 days ago
9-18452
9 days ago
107-85263
107 days
29306 YaelDillies
author:YaelDillies
chore(GroupTheory/GroupAction/Basic): don't import `Module` This is useful to be able to replace `NoZeroSMulDivisors` with `Module.IsTorsionFree` later. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
16/17 Mathlib/GroupTheory/GroupAction/Basic.lean,Mathlib/LinearAlgebra/Projectivization/Cardinality.lean 2 8 ['YaelDillies', 'eric-wieser', 'github-actions', 'riccardobrasca'] eric-wieser
assignee:eric-wieser
8-27861
8 days ago
32-39682
1 month ago
36-1025
36 days
29300 Louddy
author:Louddy
feat: SkewPolynomial ## Univariate skew polynomials Skew polynomials are represented as `SkewMonoidAlgebra R (Multiplicative ℕ)`, where `R` is usually at least a Semiring. In this file, we define `SkewPolynomial` and provide basic instances. The point if this PR is to introduce the very most basic definitions and API. From #23949. Co-authored-by: María Inés de Frutos Fernández <[mariaines.dff@gmail.com](mailto:mariaines.dff@gmail.com)> --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
178/0 Mathlib.lean,Mathlib/Algebra/SkewPolynomial/Basic.lean,docs/references.bib 3 1 ['github-actions'] riccardobrasca
assignee:riccardobrasca
8-27799
8 days ago
36-27887
1 month ago
36-27912
36 days
29314 Louddy
author:Louddy
feat(SkewMonoidAlgebra): Lifts for skew monoid algebras Lemmas about different kinds of "lifts" to `SkewMonoidAlgebra` - Similar in spirit to the MonoidAlgebra.Lift file. Co-authored-by: María Inés de Frutos Fernández <[mariaines.dff@gmail.com](mailto:mariaines.dff@gmail.com)> --- - [x] depends on: #29310 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) 238/2 Mathlib.lean,Mathlib/Algebra/SkewMonoidAlgebra/Basic.lean,Mathlib/Algebra/SkewMonoidAlgebra/Lift.lean 3 5 ['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] riccardobrasca
assignee:riccardobrasca
8-27751
8 days ago
9-81999
9 days ago
10-1017
10 days
29143 RemyDegenne
author:RemyDegenne
feat(Probability/Decision): basic properties of the Bayes risk - Comparison of the Bayes risk and the minimax risk - Maximal value of the Bayes risk and particular cases where it equals that value - Data-processing inequality --- - [x] depends on: #29137 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-measure-probability 262/1 Mathlib.lean,Mathlib/Probability/Decision/Risk/Basic.lean,Mathlib/Probability/Decision/Risk/Defs.lean 3 14 ['EtienneC30', 'RemyDegenne', 'github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] EtienneC30
assignee:EtienneC30
8-24992
8 days ago
8-24992
8 days ago
10-40884
10 days
28349 kckennylau
author:kckennylau
feat(Meta): add notation for naming stacked polynomials This PR changes the notation for naming formal variables associated to recursive polynomial-like objects. Registration is done only once per each polynomial-like functor. Usage: ```lean register_poly_vars "[" "]" Polynomial Polynomial.C Polynomial.X register_poly_vars (mv := true) "[" "]" MvPolynomial MvPolynomial.C MvPolynomial.X name_poly_vars R[a,b][C] name_poly_vars _[x,y,z] ``` `_[[x,y,z]]` allows for the hole to be substituted by any base ring, so `(x : R[[x,y,z]])` will be valid syntax. --- I have not mass deployed the new syntax at every possible location, I plan to do that in a future PR following this. Zulip: [#mathlib4 > Notation for polynomial variables](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Notation.20for.20polynomial.20variables) This is a refactor of the currently existing [Mathlib.Tactic.namePolyVarsOver](https://leanprover-community.github.io/mathlib4_docs/Mathlib/Tactic/Ring/NamePolyVars.html#Mathlib.Tactic.namePolyVarsOver). More explicitly, the current invocation `name_poly_vars x,y over R` is now `poly_variable R[x,y]`. The behaviours inherited from `name_poly_vars` are: * We do not synthesize the necessary instances (such as `[CommRing R]`) at the point of declaration, but only when the new notations are used. * We refer to an explicit term (`R` in the examples) which is "fixed", in the sense that: * it is only valid for `R` explicitly, and not any other `variable` such as `S`. * it has built-in hygiene, so if you shadow the variable by declaring a new `variable (R : Type*)`, it will still refer to the old one. And the new behaviours are: * Currently only `x` and `y` are new notations, but in the new tactic the whole ring `R[x,y]` is also available as notation. * Currently only the forward direction (i.e. elaboration, going from `x` to `MvPolynomial.X 0`) is implemented, but in the new tactic we also implement the backward direction, printing `MvPolynomial.X 0` back as `x` (and `MvPolynomial (Fin 2) R` is printed as `R[x,y]`). * Support beyond just `MvPolynomial`. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-meta 652/88 Counterexamples/CliffordAlgebraNotInjective.lean,Mathlib.lean,Mathlib/Algebra/MvPolynomial/Basic.lean,Mathlib/AlgebraicGeometry/EllipticCurve/Jacobian/Basic.lean,Mathlib/AlgebraicGeometry/EllipticCurve/Projective/Basic.lean,Mathlib/Tactic.lean,Mathlib/Tactic/PolyVariable.lean,Mathlib/Tactic/Ring/NamePolyVars.lean,MathlibTest/PolyVariable.lean,scripts/noshake.json 10 80 ['JovanGerb', 'adamtopaz', 'eric-wieser', 'github-actions', 'j-loreaux', 'kckennylau', 'kim-em', 'plp127', 'robertmaxton42', 'sgouezel'] adamtopaz
assignee:adamtopaz
8-20352
8 days ago
16-12665
16 days ago
55-78988
55 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 145/0 Mathlib/Data/Rel.lean,Mathlib/ModelTheory/Definability.lean,scripts/noshake.json 3 28 ['Timeroot', 'github-actions', 'mathlib4-merge-conflict-bot', 'staroperator'] fpvandoorn
assignee:fpvandoorn
8-16994
8 days ago
24-8079
24 days ago
105-56267
105 days
26287 mbkybky
author:mbkybky
feat(Data/ENat/Lattice): coercion to `WithBot ℕ∞` commutes with `biSup` The coercion from `ℕ∞` to `WithBot ℕ∞` commutes with `biSup` and `biInf`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data 24/0 Mathlib/Data/ENat/Lattice.lean 1 5 ['github-actions', 'kckennylau', 'mbkybky'] ericrbg
assignee:ericrbg
8-12823
8 days ago
8-12823
8 days ago
88-14047
88 days
25969 101damnations
author:101damnations
feat(RepresentationTheory/Homological/GroupHomology/Functoriality): the degree 1 part of the corestriction-coinflation exact sequence Given a `G`-representation `A` and a normal subgroup `S` of `G`, this PR defines the corestriction-coinflation short complex `H₁(S, A) ⟶ H₁(G, A) ⟶ H₁(G ⧸ S, A_S)` induced by the natural inclusion `S → G` and projections `G → G / S, A → A_S`. We prove it's exact, and that the righthand map is an epimorphism. --- - [x] depends on: #21652 - [x] depends on: #21732 - [x] depends on: #21733 - [x] depends on: #21735 - [x] depends on: #21736 - [x] depends on: #21738 - [x] depends on: #25868 - [x] depends on: #25873 - [x] depends on: #25880 - [x] depends on: #25884 - [x] depends on: #25888 - [x] depends on: #25939 - [x] depends on: #25952 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) --- *Earlier version at #22656.* t-algebra
label:t-algebra$
262/9 Mathlib/Algebra/Homology/ShortComplex/ModuleCat.lean,Mathlib/RepresentationTheory/Coinvariants.lean,Mathlib/RepresentationTheory/Homological/GroupHomology/Basic.lean,Mathlib/RepresentationTheory/Homological/GroupHomology/Functoriality.lean,Mathlib/RepresentationTheory/Homological/GroupHomology/LowDegree.lean 5 n/a ['101damnations', 'github-actions', 'jcommelin', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] nobody
7-80098
7 days ago
unknown
unknown
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 391/68 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 14 ['fweth', 'github-actions', 'joelriou', 'leanprover-community-bot-assistant', 'mathlib4-merge-conflict-bot'] joelriou
assignee:joelriou
7-62509
7 days ago
32-13272
1 month ago
51-71833
51 days
27978 smmercuri
author:smmercuri
feat: `InfinitePlace.Extension` API for extensions of infinite places. If `L / K` are fields and `v : InfinitePlace K`, then we define and add basic API for `v.Extension L` : the subtype of `w : InfinitePlace L` whose restriction to `K` matches `v`. This PR continues the work from #24881. Original PR: https://github.com/leanprover-community/mathlib4/pull/24881 --- - [x] depends on: #27977 FLT t-number-theory 49/0 Mathlib/NumberTheory/NumberField/InfinitePlace/Ramification.lean 1 3 ['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] MichaelStollBayreuth
assignee:MichaelStollBayreuth
7-62507
7 days ago
15-7284
15 days ago
15-35185
15 days
29941 themathqueen
author:themathqueen
feat(Algebra/Star): define the convolution star on linear maps This pr defines the _convolution_ star operation on linear maps `E →ₗ F` where `(star f) x = star (f (star x))`. This corresponds to a map being star-preserving, i.e., a map is self-adjoint iff it is star-preserving. The name "convolution star" is just to match the naming of the _convolution_ product in #25183. This is scoped to `ConvolutionStar` as to not conflict with the global instance on `E →ₗ[𝕜] E` on finite-dimensional Hilbert spaces, where `star` is defined as `LinearMap.adjoint`. In a finite-dimensional C⋆-algebra with a positive linear functional, which induces the GNS Hilbert space (TODO) and a coalgebra given by the adjoint of the multiplication map and the algebra unit map (TODO), we get a star ring where multiplication is given by the convolution product and star is given by the convolution star. In such a space, we can then define the isomorphism `(E →ₗ[ℂ] F) ≃⋆ₐ (F ⊗[ℂ] Eᵐᵒᵖ)`, which is an important identification in the theory of non-commutative graphs. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
94/0 Mathlib.lean,Mathlib/Algebra/Star/Convolution.lean 2 1 ['github-actions'] ocfnash
assignee:ocfnash
7-62499
7 days ago
15-19723
15 days ago
15-20484
15 days
26464 joelriou
author:joelriou
feat(LinearAlgebra): generators of pi tensor products In this PR, we show that the `R`-module `⨂[R] i, M i` is finitely generated if the index type is finite and all `M i` are finitely generated. This follows from a more precise result about generators of `⨂[R] i, M i`. --- This PR continues the work from #18725. Original PR: https://github.com/leanprover-community/mathlib4/pull/18725 file-removed t-algebra
label:t-algebra$
270/5 Mathlib.lean,Mathlib/Analysis/NormedSpace/PiTensorProduct/ProjectiveSeminorm.lean,Mathlib/Data/SubtypeNeLift.lean,Mathlib/LinearAlgebra/PiTensorProduct/Basic.lean,Mathlib/LinearAlgebra/PiTensorProduct/Finite.lean,Mathlib/LinearAlgebra/PiTensorProduct/Generators.lean,Mathlib/LinearAlgebra/TensorPower/Basic.lean,Mathlib/LinearAlgebra/TensorPower/Symmetric.lean,Mathlib/RingTheory/PiTensorProduct.lean,Mathlib/SetTheory/Cardinal/Finite.lean 10 21 ['eric-wieser', 'github-actions', 'joelriou', 'leanprover-community-bot-assistant', 'mathlib4-merge-conflict-bot'] mattrobball
assignee:mattrobball
7-41163
7 days ago
18-84385
18 days ago
85-47358
85 days
30119 Ruben-VandeVelde
author:Ruben-VandeVelde
feat: WithTop/Bot.mapD To replace Option.elim; working towards #27918 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-order 32/4 Mathlib/Order/Hom/WithTopBot.lean,Mathlib/Order/WithBot.lean 2 1 ['github-actions'] nobody
7-35723
7 days ago
7-35907
7 days ago
7-35950
7 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 401/0 Mathlib.lean,Mathlib/Dynamics/BirkhoffSum/Pointwise.lean 2 13 ['D-Thomine', 'github-actions', 'leanprover-community-bot-assistant', 'lua-vr', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] urkud
assignee:urkud
7-30007
7 days ago
44-48850
1 month ago
51-18318
51 days
30123 erdOne
author:erdOne
feat(Topology): add `IsCompact.closure_eq_nhdsKer` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-topology 11/0 Mathlib/Topology/Separation/Regular.lean 1 1 ['github-actions'] nobody
7-26562
7 days ago
7-26572
7 days ago
7-26606
7 days
30124 erdOne
author:erdOne
feat(RingTheory): `IsAdicComplete I R ↔ CompleteSpace R ∧ T2Space R` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra t-topology
label:t-algebra$
40/0 Mathlib/Order/Filter/Bases/Basic.lean,Mathlib/RingTheory/AdicCompletion/Basic.lean,Mathlib/RingTheory/AdicCompletion/Topology.lean,Mathlib/Topology/Algebra/FilterBasis.lean,Mathlib/Topology/Separation/Basic.lean 5 1 ['github-actions'] nobody
7-25509
7 days ago
7-25509
7 days ago
7-25613
7 days
29935 ineol
author:ineol
fix: cache fails when Mathlib is a nightly dependency Cache should on check for the nightly-testing remote when it is run from the Mathlib root and not from a repo which depends on Mathlib. Fixes #28594 --- I don't know how to test this fix since it would need to be in a nightly release, but at least it is working when ran from from tip of master. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor CI 3/3 Cache/Requests.lean 1 3 ['github-actions', 'ineol', 'robin-carlier'] kim-em
assignee:kim-em
7-20167
7 days ago
7-20167
7 days ago
15-30810
15 days
27364 101damnations
author:101damnations
feat(RepresentationTheory/Homological/GroupCohomology): cohomology of finite cyclic groups Let `k` be a commutative ring, `G` a group and `A` a `k`-linear `G`-representation. Given endomorphisms `φ, ψ : A ⟶ A` such that `φ ∘ ψ = ψ ∘ φ = 0`. Denote by `Chains(A, φ, ψ)` the periodic chain complex `... ⟶ A --φ--> A --ψ--> A --φ--> A --ψ--> A ⟶ 0` and by `Cochains(A, φ, ψ)` the periodic cochain complex `0 ⟶ A --ψ--> A --φ--> A --ψ--> A --φ--> A ⟶ ...`. When `G` is finite and generated by `g : G`, then `P := Chains(k[G], N, ρ(g) - Id)` (with `ρ` the left regular representation) is a projective resolution of `k` as a trivial representation. In this PR we show that for `A : Rep k G`, `Hom(P, A)` is isomorphic to `Cochains(A, N, ρ_A(g) - Id)` as a complex of `k`-modules, and hence the cohomology of this complex computes group cohomology. --- - [x] depends on: #27362 - [x] depends on: #27361 - [x] depends on: #27363 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
142/1 Mathlib.lean,Mathlib/RepresentationTheory/Homological/FiniteCyclic.lean,Mathlib/RepresentationTheory/Homological/GroupCohomology/FiniteCyclic.lean 3 5 ['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] nobody
7-9186
7 days ago
7-9520
7 days ago
7-12089
7 days
27365 101damnations
author:101damnations
feat(RepresentationTheory/Homological/GroupHomology): homology of finite cyclic groups Let `k` be a commutative ring, `G` a group and `A` a `k`-linear `G`-representation. Given endomorphisms `φ, ψ : A ⟶ A` such that `φ ∘ ψ = ψ ∘ φ = 0`. Denote by `Chains(A, φ, ψ)` the periodic chain complex `... ⟶ A --φ--> A --ψ--> A --φ--> A --ψ--> A ⟶ 0`. When `G` is finite and generated by `g : G`, then `P := Chains(k[G], N, ρ(g) - Id)` (with `ρ` the left regular representation) is a projective resolution of `k` as a trivial representation. In this PR we show that for `A : Rep k G`, `(A ⊗ P)_G` is isomorphic to `Chains(A, N, ρ_A(g) - Id)` as a complex of `k`-modules, and hence the homology of this complex computes group homology. --- - [x] depends on: #27362 - [x] depends on: #27361 - [x] depends on: #27363 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
142/1 Mathlib.lean,Mathlib/RepresentationTheory/Homological/FiniteCyclic.lean,Mathlib/RepresentationTheory/Homological/GroupHomology/FiniteCyclic.lean 3 5 ['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] nobody
7-9178
7 days ago
7-9406
7 days ago
7-11855
7 days
26975 Whysoserioushah
author:Whysoserioushah
feat: a norm_num extension for complex numbers co-authored-by : @thefundamentaltheor3m, @hrmacbeth --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-meta 350/0 Mathlib.lean,Mathlib/Analysis/RCLike/Basic.lean,Mathlib/Tactic.lean,Mathlib/Tactic/NormNum/NormNumI.lean,MathlibTest/norm_numI.lean 5 47 ['Whysoserioushah', 'dupuisf', 'eric-wieser', 'github-actions', 'hrmacbeth'] robertylewis
assignee:robertylewis
7-8417
7 days ago
84-223
2 months ago
84-4532
84 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 93/0 Mathlib.lean,Mathlib/Util/AliasIn.lean,MathlibTest/Util/AliasIn.lean 3 1 ['github-actions'] nobody
7-6084
7 days ago
7-6084
7 days ago
7-6063
7 days
30130 Bergschaf
author:Bergschaf
feat(GroupTheory/FreeGroup/Orbit): The orbit of a point generated by parts of a free group can be "duplicated" Applying `w⁻¹` to the orbit generated by all elements of a free group that start with `w` yields the orbit generated by all the words that start with every letter execpt `w⁻` (and the original point) The orbit of a point `x` generated by a set of group elements `s` defined as all the points that can be reached by applying the elements of `s` to `x`. A special case of this result is needed for the banach tarski theorem. --- I tried my best to shorten the proof of orbit.duplicate, but is quite long. There are some aspects that are duplicated due to case splits but I don't konw if it is possible to avoid that. I'd apprectiate some tips on that. And I'm not quite sure about the naming of the theorems and definitions, please let me know if you have other (better) ideas! [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-group-theory 135/0 Mathlib.lean,Mathlib/GroupTheory/FreeGroup/Orbit.lean 2 1 ['github-actions'] nobody
6-80495
6 days ago
7-9303
7 days ago
7-9346
7 days
30141 shalliso
author:shalliso
fix(Topology/Baire/Lemmas): fix index type in isMeagre_iUnion The index set ι needs to be of type Sort* instead of type Type* in isMeagre_iUnion otherwise I get the following message when I try to use it: typeclass instance problem is stuck, it is often due to metavariables Countable ?m.27 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-topology 1/1 Mathlib/Topology/GDelta/Basic.lean 1 1 ['github-actions'] nobody
6-75215
6 days ago
6-75228
6 days ago
6-75263
6 days
30140 chrisflav
author:chrisflav
feat(AlgebraicGeometry): locally directed colimits in `P.Over ⊤ S` We lift the colimit properties of `Scheme` to `P.Over ⊤ S` if `IsLocalAtSource P`. In particular, `P.Over ⊤ S` has pushouts along open immersions and (small) coproducts. We also add two instances, that make ``` example [IsLocalAtSource P] {U X Y : Scheme.{u}} (f : U ⟶ X) (g : U ⟶ Y) [IsOpenImmersion f] [IsOpenImmersion g] : HasPushout f g := inferInstance ``` work. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebraic-geometry 164/0 Mathlib.lean,Mathlib/AlgebraicGeometry/Limits.lean,Mathlib/AlgebraicGeometry/LimitsOver.lean,Mathlib/CategoryTheory/Limits/MorphismProperty.lean,Mathlib/CategoryTheory/MorphismProperty/Comma.lean 5 1 ['github-actions'] nobody
6-73114
6 days ago
6-76412
6 days ago
6-76390
6 days
29728 ADA-Projects
author:ADA-Projects
feat(Topology/KrullDimension): add subspace dimension inequality This PR extends topological Krull dimension theory with basic results about subspaces. - Add mapIrreducibleClosed function for canonical maps between irreducible closed sets - Prove injectivity and strict monotonicity of these maps - Establish partial order structure on IrreducibleCloseds - Prove topKrullDim_subspace_le theorem showing dim(Y) ≤ dim(X) for subspaces **Update (per reviewer feedback):** Reorganized code structure as requested: - Moved `IrreducibleCloseds` extensions from `KrullDimension.lean` to `Sets/Closeds.lean` - This includes `PartialOrder` instance, `map` functions, and embedding lemmas - Better modularity: other files can now use `IrreducibleCloseds` without importing Krull dimension theory The main result `topologicalKrullDim_subspace_le` remains the same - any subspace Y has dim(Y) ≤ dim(X). Some sections of this code (and documentation) were generated with the help of Gemini. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-topology 146/20 Mathlib/Topology/KrullDimension.lean,Mathlib/Topology/Sets/Closeds.lean 2 9 ['ADA-Projects', 'fpvandoorn', 'github-actions', 'kim-em'] PatrickMassot
assignee:PatrickMassot
6-62505
6 days ago
14-31945
14 days ago
14-48666
14 days
29964 Vierkantor
author:Vierkantor
feat(TacticAnalysis): check if we are in a `try`/`anyGoals` context This PR adds a check if the tactic is being run in a `try` or `anyGoals` call, so that we do not add a warning for the original tactic failing in this context. This was the source of a few "original tactic failed" in the `grind` regression reports. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-meta 71/31 Mathlib/Tactic/TacticAnalysis.lean,Mathlib/Tactic/TacticAnalysis/Declarations.lean,MathlibTest/TacticAnalysis.lean 3 1 ['github-actions'] adamtopaz
assignee:adamtopaz
6-62498
6 days ago
14-34894
14 days ago
14-34873
14 days
29967 kim-em
author:kim-em
chore: fix longest pole utilities, and verify in CI We should consider outright deleting these. The fact that they were broken is good evidence they haven't been used recently. Sebastian also has a good replacement available (that is aware of the module system), although I'm not sure it's deployed yet. CI 26/22 .github/build.in.yml,.github/workflows/bors.yml,.github/workflows/build.yml,.github/workflows/build_fork.yml,LongestPole/Main.lean,LongestPole/Unused.lean 6 2 ['bryangingechen', 'github-actions'] bryangingechen
assignee:bryangingechen
6-62497
6 days ago
14-26099
14 days ago
14-26136
14 days
29976 AntoineChambert-Loir
author:AntoineChambert-Loir
feat(Topology/Semicontinuous): lower bounds on compact sets Prove that lower semicontinuous functions attain their lower bound on nonempty compact sets, and the analogous lemma for upper semicontinuous functions. By the way, add several basic results for semicontinuous functions, relating the WithinAt, At, On versions. Co-authored with @ADedecker --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) 300/1 Mathlib/Order/Filter/Extr.lean,Mathlib/Topology/Semicontinuous.lean 2 1 ['github-actions'] TwoFX
assignee:TwoFX
6-62495
6 days ago
13-81860
13 days ago
13-81837
13 days
26219 Thmoas-Guan
author:Thmoas-Guan
feat(RingTheory/KrullDimension): Krull Dimension of quotient regular sequence We show that if M is a finite module over a Noetherian local ring R, [r₁, …, rₙ] is an M-sequence, then dim M⧸(r₁, …, rₙ)M + n = dim M. Co-authored-by: Yongle Hu @mbkybky --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory 225/15 Mathlib.lean,Mathlib/LinearAlgebra/Quotient/Basic.lean,Mathlib/RingTheory/Ideal/MinimalPrime/Localization.lean,Mathlib/RingTheory/Jacobson/Ideal.lean,Mathlib/RingTheory/KrullDimension/Module.lean,Mathlib/RingTheory/KrullDimension/Regular.lean,Mathlib/RingTheory/LocalRing/MaximalIdeal/Basic.lean,Mathlib/RingTheory/Nakayama.lean,Mathlib/RingTheory/Support.lean 9 n/a ['Thmoas-Guan', 'chrisflav', 'github-actions', 'leanprover-community-bot-assistant', 'mbkybky'] chrisflav
assignee:chrisflav
6-58329
6 days ago
unknown
unknown
28241 alreadydone
author:alreadydone
chore(Data): `SetLike Finset` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data 56/65 Counterexamples/AharoniKorman.lean,Mathlib/Algebra/BigOperators/Finprod.lean,Mathlib/Algebra/Group/Pointwise/Finset/Basic.lean,Mathlib/Algebra/Module/FinitePresentation.lean,Mathlib/Algebra/Squarefree/Basic.lean,Mathlib/Combinatorics/Additive/RuzsaCovering.lean,Mathlib/Combinatorics/SimpleGraph/Connectivity/WalkCounting.lean,Mathlib/Data/DFinsupp/Defs.lean,Mathlib/Data/Finset/Attach.lean,Mathlib/Data/Finset/Defs.lean,Mathlib/Data/Finset/Insert.lean,Mathlib/Data/Finset/Union.lean,Mathlib/FieldTheory/Finite/GaloisField.lean,Mathlib/FieldTheory/Perfect.lean,Mathlib/GroupTheory/Perm/Centralizer.lean,Mathlib/GroupTheory/Perm/Cycle/Basic.lean,Mathlib/LinearAlgebra/Finsupp/Supported.lean,Mathlib/LinearAlgebra/LinearIndependent/Basic.lean,Mathlib/LinearAlgebra/LinearIndependent/Defs.lean,Mathlib/MeasureTheory/Integral/IntegrableOn.lean,Mathlib/ModelTheory/Semantics.lean,Mathlib/Order/CountableDenseLinearOrder.lean,Mathlib/Probability/Independence/Kernel.lean,Mathlib/RingTheory/Ideal/Quotient/Index.lean,Mathlib/RingTheory/IntegralClosure/IsIntegral/Basic.lean,Mathlib/RingTheory/Spectrum/Prime/Polynomial.lean,Mathlib/Topology/Separation/Basic.lean 27 5 ['alreadydone', 'github-actions', 'j-loreaux', 'mathlib4-merge-conflict-bot'] nobody
6-57571
6 days ago
6-57571
6 days ago
39-44543
39 days
29558 Thmoas-Guan
author:Thmoas-Guan
feat(Algebra): definition of global dimension In this PR, we define projective dimension and global dimension using `CategoryTheory.HasProjectiveDimensionLT` --- - [ ] depends on: #29882 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory 212/0 Mathlib.lean,Mathlib/RingTheory/GlobalDimension.lean 2 7 ['Thmoas-Guan', 'erdOne', 'github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] erdOne
assignee:erdOne
6-56136
6 days ago
15-20233
15 days ago
16-22490
16 days
30148 mbkybky
author:mbkybky
chore(RingTheory/Spectrum/Prime/Module): golf `stableUnderSpecialization_support` using `mem_support_mono` Golf [Module.stableUnderSpecialization_support](https://leanprover-community.github.io/mathlib4_docs/Mathlib/RingTheory/Spectrum/Prime/Module.html#Module.stableUnderSpecialization_support) using [Module.mem_support_mono](https://leanprover-community.github.io/mathlib4_docs/Mathlib/RingTheory/Support.html#Module.mem_support_mono). --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory 2/6 Mathlib/RingTheory/Spectrum/Prime/Module.lean 1 1 ['github-actions'] nobody
6-53791
6 days ago
6-53804
6 days ago
6-53840
6 days
30003 vlad902
author:vlad902
feat(Order): helper lemmas for `IsChain`/`IsAntichain` These were useful in formalizing Dilworth's theorem. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-order 16/0 Mathlib/Order/Antichain.lean,Mathlib/Order/Preorder/Chain.lean 2 6 ['github-actions', 'mathlib4-merge-conflict-bot', 'plp127', 'vlad902'] nobody
6-43562
6 days ago
6-43591
6 days ago
12-86334
12 days
29835 vlad902
author:vlad902
feat(Order): add `IsMaxAntichain` and some lemmas for `IsMaxChain` Define `IsMaxAntichain` to be the antichain analogue of `IsMaxChain` and add some useful lemmas to both that I needed for proving Mirsky's theorem. - [ ] depends on: #29834 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-order 51/0 Mathlib/Order/Antichain.lean,Mathlib/Order/Preorder/Chain.lean 2 3 ['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] nobody
6-43099
6 days ago
6-79199
6 days ago
6-79526
6 days
30069 IvanRenison
author:IvanRenison
feat(Combinatorics/SimpleGraph): add lemma `IsTree.dist_ne_of_adj` and necessary lemmas This contribution was created as part of the Utrecht Summerschool "Formalizing Mathematics in Lean" in July 2025. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-combinatorics 34/0 Mathlib/Combinatorics/SimpleGraph/Acyclic.lean 1 7 ['github-actions', 'themathqueen', 'vlad902'] nobody
6-36197
6 days ago
10-9292
10 days ago
10-15044
10 days
30120 FernandoChu
author:FernandoChu
feat(CategoryTheory): Pullback of equalizer is an equalizer We show that the pullback of an equalizer (seen as a subobject) along some morphism `h` is the subobject that comes from the equalizer of the two original arrows precomposed with `h`. A `TODO` was completed in the process. This is a prerequisite of the [MTT project](https://github.com/kyoDralliam/model-theory-topos), which aims to use the internal language of toposes to reason about e.g. sheaves. large-import t-category-theory 112/2 Mathlib/CategoryTheory/Limits/Shapes/Equalizers.lean,Mathlib/CategoryTheory/Limits/Shapes/Pullback/PullbackCone.lean,Mathlib/CategoryTheory/Subobject/Basic.lean,Mathlib/CategoryTheory/Subobject/FactorThru.lean,Mathlib/CategoryTheory/Subobject/Limits.lean 5 3 ['FernandoChu', 'github-actions', 'joelriou'] nobody
6-29490
6 days ago
6-29490
6 days ago
6-35129
6 days
30152 YaelDillies
author:YaelDillies
feat(Filter): a finite set is eventually a subset of any exhaustion This will be used to prove a sort of compactness result for finite minors of a graph. From the ProofBench workshop --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-order 4/0 Mathlib/Order/Filter/Finite.lean 1 2 ['github-actions', 'kckennylau'] nobody
6-28755
6 days ago
6-38813
6 days ago
6-38808
6 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 9/4 Mathlib/Combinatorics/SimpleGraph/Basic.lean 1 1 ['github-actions'] nobody
6-28239
6 days ago
6-28247
6 days ago
6-28282
6 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 227/0 Mathlib.lean,Mathlib/Geometry/Manifold/PrincipalFiberBundle/PrincipalGBundle.lean 2 5 ['github-actions', 'grunweg'] nobody
6-27187
6 days ago
6-40161
6 days ago
7-33114
7 days
29734 bwangpj
author:bwangpj
feat(Probability/Kernel): \phi-irreducibility of kernels Define powers of kernels, the Chapman-Kolmogorov equations, as well as \phi-irreducibility of kernels, following Robert-Casella, "Monte Carlo Statistical Methods", Definition 6.13. Co-authored-by: Matteo Cipollina @or4nge19 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-measure-probability 160/8 Mathlib.lean,Mathlib/Probability/Kernel/Composition/Comp.lean,Mathlib/Probability/Kernel/Composition/CompMap.lean,Mathlib/Probability/Kernel/Irreducible.lean,docs/references.bib 5 6 ['RemyDegenne', 'bwangpj', 'github-actions'] RemyDegenne
assignee:RemyDegenne
6-22034
6 days ago
16-11192
16 days ago
22-50231
22 days
30163 NotWearingPants
author:NotWearingPants
feat(Data/Set/Lattice): useful equivalences of `biUnion` and `biInter` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data new-contributor 25/0 Mathlib/Data/Set/Lattice.lean 1 1 ['github-actions'] nobody
6-17353
6 days ago
6-17353
6 days ago
6-17404
6 days
27400 dleijnse
author:dleijnse
feat: define geometrically reduced algebras Define geometrically reduced algebras, and prove that if all finitely generated subalgebras of an algebra `A` are geometrically reduced, then `A` is geometrically reduced. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-algebra
label:t-algebra$
117/0 Mathlib.lean,Mathlib/RingTheory/Adjoin/FG.lean,Mathlib/RingTheory/Flat/Basic.lean,Mathlib/RingTheory/Nilpotent/Defs.lean,Mathlib/RingTheory/Nilpotent/GeometricallyReduced.lean,Mathlib/RingTheory/TensorProduct/Basic.lean 6 72 ['dleijnse', 'github-actions', 'joelriou', 'kckennylau'] joelriou
assignee:joelriou
6-16458
6 days ago
6-16495
6 days ago
73-28308
73 days
29759 NotWearingPants
author:NotWearingPants
feat(Analysis/SpecificLimits/Fibonacci): prove that the ratio of consecutive Fibonacci numbers tends to the golden ratio --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) maintainer-merge new-contributor t-analysis 36/0 Mathlib.lean,Mathlib/Analysis/SpecificLimits/Fibonacci.lean 2 7 ['NotWearingPants', 'Ruben-VandeVelde', 'github-actions', 'kckennylau'] nobody
6-13196
6 days ago
6-13197
6 days ago
13-68574
13 days
30004 luigi-massacci
author:luigi-massacci
feat(MeasureTheory/Integral/TestAgainst): integrating BCFs against a finite measure or an L1Loc map as CLMs This PR merges #29511 and #29748. Create a new file `TestAgainst.lean` with definitions wrapping integration against a finite measure or a locally integrable map as continuous linear maps on bounded continuous functions. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-measure-probability t-analysis 113/1 Mathlib.lean,Mathlib/MeasureTheory/Integral/BoundedContinuousFunction.lean,Mathlib/MeasureTheory/Integral/TestAgainst.lean 3 38 ['EtienneC30', 'github-actions', 'j-loreaux', 'luigi-massacci'] EtienneC30
assignee:EtienneC30
6-9632
6 days ago
6-9813
6 days ago
12-28164
12 days
26267 vasnesterov
author:vasnesterov
feat(Analysis/Calculus): Taylor series converges to function on whole ball * Prove `FormalMultilinearSeries.AnalyticOnNhd`: the sum of series is analytic on its ball of convergence. * Prove `AnalyticOn.hasFPowerSeriesOnBall`: a variant of `AnalyticAt.hasFPowerSeriesAt` which gives convergence to the function on the ball of convergence. --- - [x] depends on: #23745 - [x] depends on: #23747 - [x] depends on: #23748 - [x] depends on: #26247 This PR continues the work from #23749. Original PR: https://github.com/leanprover-community/mathlib4/pull/23749 t-analysis 65/0 Mathlib.lean,Mathlib/Analysis/Analytic/ChangeOrigin.lean,Mathlib/Analysis/Calculus/IteratedDeriv/ConvergenceOnBall.lean 3 5 ['github-actions', 'grunweg', 'mathlib4-dependent-issues-bot', 'vasnesterov'] urkud
assignee:urkud
6-8736
6 days ago
50-13295
1 month ago
96-84564
96 days
30180 mcdoll
author:mcdoll
feat(Analysis/Calculus): add a version of bounding iterated derivatives of compositions with fewer assumptions on differentiability --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-analysis 17/3 Mathlib/Analysis/Calculus/ContDiff/Bounds.lean 1 1 ['github-actions'] nobody
6-2131
6 days ago
6-2137
6 days ago
6-2176
6 days
30137 vlad902
author:vlad902
feat(SimpleGraph): subsingleton/nontrivial helper lemmas Helper lemmas I found useful in mutliple PRs for dispatching trivial cases. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-combinatorics 22/0 Mathlib/Combinatorics/SimpleGraph/Basic.lean 1 1 ['github-actions'] nobody
5-82002
5 days ago
6-79592
6 days ago
6-79628
6 days
30173 kckennylau
author:kckennylau
chore: generalise extensionality lemmas for localization This PR generalises some extensionality lemmas for morphisms from localization. The codomains are generalised from `CommMonoid` to `Monoid`, and from `CommSemiring` to `Semiring`. Then two new extensionality lemmas for algebra morphisms are added. Currently `Submonoid.LocalizationMap.epic_of_localizationMap` says that if `M` and `P` are commutative monoids, and `f : M →* N` is a localization map for a submonoid `S`, then two monoid homs `j k : N →* P` are equal if they are equal after composing with `f`. This PR relaxes the assumption on `P` from `CommMonoid` to `Monoid`. Similar generalisations are made in other places, and then two new lemmas for `AlgHom` are added. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
37/18 Mathlib/Algebra/Category/Ring/Instances.lean,Mathlib/AlgebraicGeometry/StructureSheaf.lean,Mathlib/GroupTheory/MonoidLocalization/Basic.lean,Mathlib/RingTheory/Localization/Basic.lean,Mathlib/RingTheory/Localization/Defs.lean 5 1 ['github-actions'] nobody
5-81786
5 days ago
6-4485
6 days ago
6-4471
6 days
29705 llllvvuu
author:llllvvuu
feat(LinearAlgebra/Matrix): formula for charpoly of an inverse matrix Co-authored-by: Aristotle Harmonic --- - [x] depends on: #29709 to re-organized some imports [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
14/0 Mathlib/LinearAlgebra/Matrix/Charpoly/Coeff.lean 1 7 ['github-actions', 'llllvvuu', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'themathqueen'] Vierkantor
assignee:Vierkantor
5-80669
5 days ago
14-8897
14 days ago
14-18455
14 days
29284 Jlh18
author:Jlh18
feat(CategoryTheory): naturality lemmas for Core construction Lemmas for PR #29283 to prove that `Core` is the right adjoint to the forgetful functor from `Cat` to `Grpd`. These lemmas are more general than that setting, and need not be stated in the bundled format. - [ ] depends on: #29250 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-category-theory 62/0 Mathlib/CategoryTheory/Core.lean 1 14 ['Jlh18', 'adomani', 'github-actions', 'joelriou', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] nobody
5-75640
5 days ago
5-75640
5 days ago
20-3061
20 days
29004 euprunin
author:euprunin
chore: change from `:= by rfl` to `:= rfl` For `@[simp]` lemmas this makes them usable by `dsimp`; others are stylistic cleanup (but they're now "`dsimp`-ready" if tagged later). --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) 138/242 Mathlib/Algebra/Algebra/NonUnitalHom.lean,Mathlib/Algebra/Category/ModuleCat/Presheaf.lean,Mathlib/Algebra/DirectSum/Module.lean,Mathlib/Algebra/DirectSum/Ring.lean,Mathlib/Algebra/Group/AddChar.lean,Mathlib/Algebra/Group/Subgroup/Defs.lean,Mathlib/Algebra/GroupWithZero/ProdHom.lean,Mathlib/Algebra/Homology/HomotopyCategory/HomComplex.lean,Mathlib/Algebra/Homology/ShortComplex/LeftHomology.lean,Mathlib/Algebra/Homology/Single.lean,Mathlib/Algebra/Lie/Basic.lean,Mathlib/Algebra/Lie/OfAssociative.lean,Mathlib/Algebra/Lie/Submodule.lean,Mathlib/Algebra/Order/Hom/MonoidWithZero.lean,Mathlib/Algebra/Order/Hom/Ring.lean,Mathlib/Algebra/Polynomial/AlgebraMap.lean,Mathlib/Algebra/Polynomial/Derivation.lean,Mathlib/Algebra/Polynomial/Module/Basic.lean,Mathlib/Algebra/Ring/Hom/Defs.lean,Mathlib/Algebra/RingQuot.lean,Mathlib/Algebra/Vertex/HVertexOperator.lean,Mathlib/Algebra/Vertex/VertexOperator.lean,Mathlib/AlgebraicTopology/SimplicialSet/StdSimplex.lean,Mathlib/Analysis/Asymptotics/ExpGrowth.lean,Mathlib/Analysis/CStarAlgebra/GelfandDuality.lean,Mathlib/Analysis/Calculus/FDeriv/Prod.lean,Mathlib/Analysis/Complex/UpperHalfPlane/Basic.lean,Mathlib/Analysis/Distribution/SchwartzSpace.lean,Mathlib/Analysis/Normed/Affine/Isometry.lean,Mathlib/Analysis/Normed/Group/Seminorm.lean,Mathlib/Analysis/Normed/Module/Span.lean,Mathlib/Analysis/SpecialFunctions/Complex/CircleAddChar.lean,Mathlib/Analysis/SpecialFunctions/Stirling.lean,Mathlib/CategoryTheory/Closed/Monoidal.lean,Mathlib/CategoryTheory/Distributive/Monoidal.lean,Mathlib/CategoryTheory/Limits/Presheaf.lean,Mathlib/CategoryTheory/Limits/Shapes/Pullback/Cospan.lean,Mathlib/CategoryTheory/Monoidal/Comon_.lean,Mathlib/CategoryTheory/Monoidal/Mod_.lean,Mathlib/CategoryTheory/Yoneda.lean,Mathlib/Combinatorics/SimpleGraph/Walk.lean,Mathlib/Computability/AkraBazzi/AkraBazzi.lean,Mathlib/Computability/AkraBazzi/SumTransform.lean,Mathlib/Data/Matrix/Basic.lean,Mathlib/Data/Nat/Factorization/PrimePow.lean,Mathlib/Data/Nat/PartENat.lean,Mathlib/Data/PFunctor/Multivariate/Basic.lean,Mathlib/Data/Real/Embedding.lean,Mathlib/Data/Rel.lean,Mathlib/Data/Seq/Basic.lean,Mathlib/Data/Set/Lattice.lean,Mathlib/Data/Set/Pairwise/Lattice.lean,Mathlib/Data/Subtype.lean,Mathlib/Geometry/Manifold/Bordism.lean,Mathlib/GroupTheory/Coxeter/Basic.lean,Mathlib/GroupTheory/GroupAction/Hom.lean,Mathlib/GroupTheory/SpecificGroups/Quaternion.lean,Mathlib/LinearAlgebra/AffineSpace/Simplex/Basic.lean,Mathlib/LinearAlgebra/Dual/Defs.lean,Mathlib/LinearAlgebra/Lagrange.lean,Mathlib/LinearAlgebra/Matrix/GeneralLinearGroup/Defs.lean,Mathlib/LinearAlgebra/Multilinear/TensorProduct.lean,Mathlib/LinearAlgebra/Projectivization/Action.lean,Mathlib/LinearAlgebra/RootSystem/Hom.lean,Mathlib/LinearAlgebra/RootSystem/Reduced.lean,Mathlib/LinearAlgebra/Span/Basic.lean,Mathlib/LinearAlgebra/TensorProduct/Pi.lean,Mathlib/MeasureTheory/MeasurableSpace/Embedding.lean,Mathlib/ModelTheory/Semantics.lean,Mathlib/NumberTheory/FLT/Polynomial.lean,Mathlib/NumberTheory/FactorisationProperties.lean,Mathlib/NumberTheory/Harmonic/ZetaAsymp.lean,Mathlib/NumberTheory/Padics/WithVal.lean,Mathlib/Order/BoundedOrder/Basic.lean,Mathlib/RepresentationTheory/Coinvariants.lean,Mathlib/RepresentationTheory/Homological/GroupCohomology/Functoriality.lean,Mathlib/RepresentationTheory/Homological/GroupHomology/LowDegree.lean,Mathlib/RingTheory/AlgebraTower.lean,Mathlib/RingTheory/Bialgebra/Hom.lean,Mathlib/RingTheory/HahnSeries/Addition.lean,Mathlib/RingTheory/Ideal/Norm/AbsNorm.lean,Mathlib/RingTheory/Ideal/Quotient/Operations.lean,Mathlib/SetTheory/Surreal/Basic.lean,Mathlib/SetTheory/ZFC/Class.lean,Mathlib/Tactic/Module.lean,Mathlib/Tactic/NormNum/PowMod.lean,Mathlib/Topology/Algebra/Algebra/Equiv.lean,Mathlib/Topology/Algebra/Module/WeakDual.lean,Mathlib/Topology/Category/Profinite/Nobeling/Basic.lean,Mathlib/Topology/Category/Profinite/Nobeling/ZeroLimit.lean,Mathlib/Topology/Category/TopCat/Opens.lean,Mathlib/Topology/ContinuousMap/Units.lean,Mathlib/Topology/LocallyFinsupp.lean,Mathlib/Topology/PartitionOfUnity.lean,Mathlib/Topology/Sets/Closeds.lean 95 21 ['eric-wieser', 'euprunin', 'github-actions', 'leanprover-bot', 'leanprover-community-mathlib4-bot', 'mathlib4-merge-conflict-bot'] TwoFX
assignee:TwoFX
5-74905
5 days ago
5-74928
5 days ago
15-61195
15 days
29356 Paul-Lez
author:Paul-Lez
feat(Mathlib/FieldTheory/RatFunc/Basic): add characteristic instances for `RatFunc` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
63/17 Mathlib.lean,Mathlib/Algebra/Algebra/Basic.lean,Mathlib/Algebra/Algebra/Field.lean,Mathlib/Algebra/Algebra/IsSimpleRing.lean,Mathlib/Algebra/CharP/Algebra.lean,Mathlib/Analysis/RCLike/Basic.lean,Mathlib/FieldTheory/Differential/Liouville.lean,Mathlib/FieldTheory/Finite/Basic.lean,Mathlib/FieldTheory/Finite/GaloisField.lean,Mathlib/FieldTheory/RatFunc/Basic.lean,Mathlib/RingTheory/Localization/FractionRing.lean 11 8 ['Paul-Lez', 'eric-wieser', 'github-actions'] kim-em
assignee:kim-em
5-62510
5 days ago
34-72355
1 month ago
34-72385
34 days
29863 FernandoChu
author:FernandoChu
feat(CategoryTheory): Colimits in `Subobject X` Adds colimits to `Subobject X`. Together with https://github.com/leanprover-community/mathlib4/pull/29253, this will show existence of lubs in the poset of subobjects. This is a prerequisite of the [MTT project](https://github.com/kyoDralliam/model-theory-topos), which aims to use the internal language of toposes to reason about e.g. sheaves. t-category-theory 71/0 Mathlib/CategoryTheory/Subobject/Basic.lean,Mathlib/CategoryTheory/Subobject/MonoOver.lean 2 2 ['github-actions', 'mathlib4-merge-conflict-bot'] riccardobrasca
assignee:riccardobrasca
5-62508
5 days ago
13-37780
13 days ago
18-4949
18 days
29982 hrmacbeth
author:hrmacbeth
feat: new `isolate` tactic This PR adds a new tactic, `isolate`, which "solves for x" in an equation or relation. For example: ```lean example (a b : ℝ) (f : ℝ → ℝ) : 5 * f a - 3 < b := by isolate f a -- new goal: `⊢ f a < (b + 3) / 5` ``` The `isolate` tactic may generate side goals, if these are necessary to justify the transformation. The tactic will attempt to justify such side goals using `positivity` (as in the above example), unification, or type class inference, but if unsuccessful will present them to the user. For example: ```lean example (a b c : ℝ) (f : ℝ → ℝ) : c * f a - 3 < b := by isolate f a -- new goal: `⊢ f a < (b + 3) / c` -- second (side) new goal: `⊢ 0 < c` ``` The `isolate` tactic is extensible. Coverage may be extended to new relations and new operations-to-be-undone by tagging appropriate lemmas with the new `@[isolate]` attribute. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) large-import t-meta 863/3 Mathlib.lean,Mathlib/Analysis/SpecialFunctions/Log/Basic.lean,Mathlib/Analysis/SpecialFunctions/Pow/Real.lean,Mathlib/Data/Real/Sqrt.lean,Mathlib/Tactic.lean,Mathlib/Tactic/Isolate.lean,Mathlib/Tactic/Isolate/Core.lean,Mathlib/Tactic/Isolate/Tagging.lean,Mathlib/Tactic/Relation/Symm.lean,MathlibTest/Isolate/Heavyweight.lean,MathlibTest/Isolate/Lightweight.lean,scripts/noshake.json 12 23 ['JovanGerb', 'PatrickMassot', 'github-actions', 'hrmacbeth', 'kim-em'] JovanGerb
assignee:JovanGerb
5-62504
5 days ago
12-74647
12 days ago
12-74631
12 days
29999 jeremypparker
author:jeremypparker
chore(Analysis/Fourier/AddCircle): remove stale comment --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-analysis 0/1 Mathlib/Analysis/Fourier/AddCircle.lean 1 2 ['Ruben-VandeVelde', 'github-actions', 'jeremypparker'] sgouezel
assignee:sgouezel
5-62502
5 days ago
13-31250
13 days ago
13-31284
13 days
29788 robertmaxton42
author:robertmaxton42
feat (Topology): adds bundled continuous maps for sum, sigma, subtype, mapsto, inclusion Adds a collection of bundled continuous maps and homeomorphisms, and helper lemmas for working with their compositions. Bundling of existing continuity lemmas: * `ContinuousMap.subtypeVal` * `ContinuousMap.inl` and `.inr`; `ContinuousMap.sum` bundles `Continuous.sumElim`; `ContinuousMap.sumMap`, which is a quotient map when both components are quotient maps * `ContinuousMap.sigmaMap`, which is a quotient map when given a family of quotient maps * `ContinuousMap.mapsTo` bundles `ContinuousOn.restrict_mapsTo` New functions: * `ContinuousMap.preimageValIncl : C(s ↓∩ t, t)` and `.inclPreimageVal C(s, t ↓∩ s)`, and their unbundled functions in `Set` * `Homeomorph.Set.preimageVal` witnesses that the two are opposite directions of a homeomorphism * Descending from a coherent set of subspaces is a quotient map The primary use for these bundled maps is easy composition and the ability to introduce them by rewriting right-to-left: it is much more convenient to write `subtypeVal.comp _` than to use either the anonymous constructor (which doesn't work in any position without an expected type) or `ContinuousMap.mk` (which will disappear as soon as it is coerced to a function, making it difficult to use in mixed-categorical contexts where many maps can only be reduced by introducing a composition with some other map.) This PR is part of a family of PRs that ultimately construct transformations in both directions between the concrete `Topology.RelCWComplex` and abstract `TopCat.RelativeCWComplex`. `.mapsTo` in particular bundles together a couple of potentially nontrivial proofs in a way that makes them easy to refer to later; I use it and `.subtypeVal` particularly heavily later in a dependent PR to build the cell inclusion maps on both sides of the equivalence. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) large-import 226/3 Mathlib/Data/Set/Subset.lean,Mathlib/Topology/Category/TopCat/Limits/Products.lean,Mathlib/Topology/Coherent.lean,Mathlib/Topology/Constructions.lean,Mathlib/Topology/Constructions/SumProd.lean,Mathlib/Topology/ContinuousMap/Basic.lean,scripts/noshake.json 7 6 ['adamtopaz', 'github-actions', 'robertmaxton42'] adamtopaz
assignee:adamtopaz
5-59985
5 days ago
5-60005
5 days ago
20-56086
20 days
30187 CoolRmal
author:CoolRmal
chore(Topology/MeasureTheory/Probability): Rename the file for compactly supported continuous functions. Move two lemmas `essSup_uniformOn_eq_ciSup` and `essInf_cond_count_eq_ciInf` from Mathlib/MeasureTheory/Function/EssSup.lean to Mathlib/Probability/UniformOn.lean in order to avoid warnings for import in the PR [feat(MeasureTheory): Uniqueness of Measures in the Riesz–Markov–Kakutani Representation Theorem](https://github.com/leanprover-community/mathlib4/pull/28061#top). Create a new folder named CompactlySupported and moved two related files into this folder. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) file-removed new-contributor 17/15 Mathlib.lean,Mathlib/MeasureTheory/Function/EssSup.lean,Mathlib/MeasureTheory/Integral/RieszMarkovKakutani/Basic.lean,Mathlib/Probability/Distributions/Fernique.lean,Mathlib/Probability/Moments/IntegrableExpMul.lean,Mathlib/Probability/UniformOn.lean,Mathlib/Topology/ContinuousMap/CompactlySupported/Basic.lean,Mathlib/Topology/ContinuousMap/CompactlySupported/Bounded.lean 8 1 ['github-actions'] nobody
5-39424
5 days ago
5-41391
5 days ago
5-41437
5 days
29136 YaelDillies
author:YaelDillies
feat(CategoryTheory/Monoidal): `mapMon` of a lax-braided functor is lax-braided Also move the `BraidedCategory (Mon_ C)` instance earlier in the file to avoid splitting up the functor material. I think it makes more sense like this (defining `Mon_Class`, then `Mon_`, then `Functor.mapMon`). From Toric --- - [x] depends on: #30157 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) toric t-category-theory 71/9 Mathlib/Algebra/Category/CoalgCat/ComonEquivalence.lean,Mathlib/CategoryTheory/Monoidal/Grp_.lean,Mathlib/CategoryTheory/Monoidal/Mon_.lean 3 12 ['YaelDillies', 'github-actions', 'joelriou', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] joelriou
assignee:joelriou
5-34134
5 days ago
5-34541
5 days ago
35-24947
35 days
29719 kim-em
author:kim-em
feat(Topology/Algebra/Group/Units): add topological properties of units ## Summary Add lemmas about units in topological monoids: - `Submonoid.units_isOpen`: units of open submonoids are open in the units topology - `ContinuousMulEquiv.piUnits`: homeomorphism between units of a product and product of units This content was prepared by Claude from the FLT project. Source file: `/Users/kim/projects/lean/flt/FLT/Mathlib/Topology/Algebra/Group/Units.lean` GitHub source: https://github.com/ImperialCollegeLondon/FLT/blob/main/FLT/Mathlib/Topology/Algebra/Group/Units.lean 🤖 Generated with [Claude Code](https://claude.ai/code) FLT t-topology 53/0 Mathlib.lean,Mathlib/Topology/Algebra/Group/Units.lean 2 7 ['Ruben-VandeVelde', 'github-actions', 'kim-em', 'plp127'] ADedecker
assignee:ADedecker
5-32667
5 days ago
5-32667
5 days ago
12-75836
12 days
29376 vlad902
author:vlad902
feat(SimpleGraph): helper lemmas for `Walk.IsSubwalk` t-combinatorics 29/0 Mathlib/Combinatorics/SimpleGraph/Walk.lean 1 1 ['github-actions'] awainverse
assignee:awainverse
5-32279
5 days ago
33-40196
1 month ago
33-40230
33 days
25814 vlad902
author:vlad902
feat(SimpleGraph): weaker condition for paths in acyclic graphs `IsAcyclic.isPath_iff_chain'` defines a weaker condition for proving that a walk is a path, in particular it shows that rather than proving that all vertices in the support of a walk are distinct, one must only show that consecutive edges are distinct (e.g. every other vertex must be distinct.) This leads to a simple corollary that trails are also paths in acyclic graphs. I had a need for this when formalizing Cayley graphs, since this condition maps cleanly onto words in free groups being reduced. --- *This PR continues the work from #25630.* *Original PR: https://github.com/leanprover-community/mathlib4/pull/25630* t-combinatorics 38/0 Mathlib/Combinatorics/SimpleGraph/Acyclic.lean,Mathlib/Combinatorics/SimpleGraph/Paths.lean 2 2 ['github-actions', 'vlad902'] kmill
assignee:kmill
5-31275
5 days ago
119-14688
3 months ago
119-14663
119 days
29164 vlad902
author:vlad902
feat(SimpleGraph): Hall's Marriage Theorem for bipartite graphs Derive the graph theoretic proof of Hall's marriage theorem from the combinatorial version. Note that I specifically implement this for the more general case of infinite graphs that are locally finite (e.g. every vertex has only finite neighbors.) As a result, the theorem depends on some category theoretic infrastructure required for the infinite combinatorial formulation of Hall's Marriage Theorem and hence I've placed the theorems into their own file to avoid requiring it in `Matching.lean` - [ ] depends on: #29162 t-combinatorics 130/7 Mathlib.lean,Mathlib/Combinatorics/Hall/Basic.lean,Mathlib/Combinatorics/SimpleGraph/Hall.lean,Mathlib/Combinatorics/SimpleGraph/Matching.lean,docs/1000.yaml 5 2 ['github-actions', 'mathlib4-dependent-issues-bot'] b-mehta
assignee:b-mehta
5-22560
5 days ago
25-51505
25 days ago
25-54729
25 days
30200 yonggyuchoimath
author:yonggyuchoimath
feat(CategoryTheory/Limits/Opposites) : add opposites of coforks and forks This PR adds missing definitions surrounding `op` and `unop` of coforks and forks. In `CategoryTheory/Limits/Shapes/Equalizers.lean`: - `CoforkOfπ.ext` : Adds an extensionality `def` corresponding to theexisting `ForkOfι.ext` In `CategoryTheory/Limits/Opposites.lean`: - `parallelPairOp`: the dual behavior for `parallelPair` (similar to `spanOp`, `cospanOp`) - `pullbackIsoOpPushout`: the dual version of the existing `pullbackIsoUnopPushout` - `Cofork.unop`, `Cofork.op`, `Fork.unop`, `Fork.op`: define `unop` and `op` of `Cofork` and `Fork` - `isColimitEquivIsLimitOp`: A cofork in `C` is a colimit if and only if its opposite is limit in `Cᵒᵖ` - `isColimitOfπEquivIsLimitOp`: `Cofork.ofπ π` is colimit in `C` if and only if `Fork.ofι π.op` is limit in `Cᵒᵖ` Relevant dual statements have also been added. Further notes: - line 1187, 1215 : I was not able to remove the lengthy `simp only` - The file length is now almost 1500. t-category-theory 365/0 Mathlib/CategoryTheory/Limits/Opposites.lean,Mathlib/CategoryTheory/Limits/Shapes/Equalizers.lean 2 1 ['github-actions'] nobody
5-5574
5 days ago
5-5880
5 days ago
5-5914
5 days
29365 staroperator
author:staroperator
feat(SetTheory/ZFC): add `ZFSet.card` The same as `ZFSet.rank`, we define `ZFSet.card` as `ZFSet.{u} → Cardinal.{u}` and prove some basic properties. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-set-theory 123/4 Mathlib.lean,Mathlib/SetTheory/Cardinal/Basic.lean,Mathlib/SetTheory/ZFC/Basic.lean,Mathlib/SetTheory/ZFC/Cardinal.lean 4 21 ['YaelDillies', 'github-actions', 'staroperator', 'vihdzp'] YaelDillies
assignee:YaelDillies
5-177
5 days ago
5-177
5 days ago
33-79681
33 days
30206 NotWearingPants
author:NotWearingPants
feat(Combinators/SimpleGraph/Hamiltonian): `p.support.length = Fintype.card α` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-combinatorics easy 8/0 Mathlib/Combinatorics/SimpleGraph/Hamiltonian.lean 1 2 ['NotWearingPants', 'github-actions'] nobody
4-86343
4 days ago
4-86354
4 days ago
4-86396
4 days
30209 Ruben-VandeVelde
author:Ruben-VandeVelde
feat: some TwoSidedIdeal.span lemmas --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory FLT 16/0 Mathlib/RingTheory/TwoSidedIdeal/Operations.lean 1 1 ['github-actions'] nobody
4-81391
4 days ago
4-81483
4 days ago
4-81519
4 days
27107 AntoineChambert-Loir
author:AntoineChambert-Loir
feat(GroupTheory/GroupAction/SubMulAction/Combination) : combinations and group actions `Nat.Combination X n` is the type all `s : Finset X` such that `s.card = n`. This PR provides some API for this subtype and the `SubMulAction` it inherits when a group acts on `X`. It will be used in conjunction with the description of some maximal subgroups of `Equiv.Perm X` to construct primitive actions. Question on the names: when `X` is a fintype, there is `Finset.powersetCard` that gives the same object, as a `Finset`. But the present PR also applies when `X` is infinite. Then maybe `Nat.Combination` should be renamed as `Set.powersetCard`? --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-group-theory 324/0 Mathlib.lean,Mathlib/Data/Fintype/EquivFin.lean,Mathlib/Data/Nat/Choose/Basic.lean,Mathlib/GroupTheory/GroupAction/SubMulAction/Combination.lean 4 39 ['AntoineChambert-Loir', 'alreadydone', 'github-actions', 'tb65536'] alreadydone
assignee:alreadydone
4-79958
4 days ago
65-30936
2 months ago
87-60676
87 days
30215 NotWearingPants
author:NotWearingPants
feat(Data/List/NodupEquivFin): add equiv with `count = 1` hypothesis --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data new-contributor easy 7/2 Mathlib/Data/List/NodupEquivFin.lean 1 2 ['NotWearingPants', 'github-actions'] nobody
4-73164
4 days ago
4-73164
4 days ago
4-73549
4 days
30214 NotWearingPants
author:NotWearingPants
feat(Data/List/Basic): add `Fin` variants of `*mem_iff_getElem` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data new-contributor easy 11/0 Mathlib/Data/List/Basic.lean 1 2 ['NotWearingPants', 'github-actions'] nobody
4-73093
4 days ago
4-73093
4 days ago
4-73846
4 days
30144 alreadydone
author:alreadydone
feat(Data/Nat): reducible binaryRec + Redefine `Nat.binaryRec` to allow kernel reduction. + Move some lemmas from Data/Nat/Bitwise to Data/Nat/BinaryRec. + Use `nsmulBinRec` for nsmul/zsmul on elliptic curves. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data t-algebra
label:t-algebra$
77/56 Mathlib/Algebra/Group/Defs.lean,Mathlib/Algebra/Group/Prod.lean,Mathlib/AlgebraicGeometry/EllipticCurve/Affine/Point.lean,Mathlib/Data/Nat/BinaryRec.lean,Mathlib/Data/Nat/BitIndices.lean,Mathlib/Data/Nat/Bits.lean,Mathlib/Data/Nat/Bitwise.lean,Mathlib/Data/Nat/Size.lean 8 4 ['github-actions', 'leanprover-bot', 'leanprover-community-mathlib4-bot'] nobody
4-71320
4 days ago
5-14858
5 days ago
5-62362
5 days
30217 NotWearingPants
author:NotWearingPants
feat(Data/List/GetD): `getD` is surjective iff every element is in the list --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data new-contributor 19/0 Mathlib/Data/List/GetD.lean 1 2 ['github-actions', 'themathqueen'] nobody
4-67995
4 days ago
4-72910
4 days ago
4-72947
4 days
30213 NotWearingPants
author:NotWearingPants
feat(Data/List/GetD): golf and add lemmas for `get` and `getElem?.get` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data new-contributor easy 18/16 Mathlib/Data/List/GetD.lean 1 8 ['NotWearingPants', 'github-actions', 'themathqueen'] nobody
4-66231
4 days ago
4-75372
4 days ago
4-75570
4 days
28893 joelriou
author:joelriou
refactor(AlgebraicTopology): redefine the topological simplex using the convexity API Before this PR, the n-dimensional topological simplex (in the `AlgebraicTopology` hierarchy) was defined as a subtype of `Fin (n + 1) → ℝ≥0`, which did not interact well with the convexity API which assumes the ambient type is a vector space. In this PR, we redefine the topological simplex functor (as a cosimplicial object in `TopCat`) using the already existing `stdSimplex` from `Analysis.Convex`. --- - [x] depends on: #28891 - [x] depends on: #28869 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebraic-topology t-convex-geometry large-import 91/108 Mathlib/AlgebraicTopology/SimplexCategory/Basic.lean,Mathlib/AlgebraicTopology/SingularSet.lean,Mathlib/AlgebraicTopology/TopologicalSimplex.lean,Mathlib/Analysis/Convex/StdSimplex.lean 4 5 ['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] robin-carlier
assignee:robin-carlier
4-62477
4 days ago
40-7776
1 month ago*
0-2609
43 minutes*
29501 Vierkantor
author:Vierkantor
test(TacticAnalysis): ensure `classical`'s effects are picked up This test case used to fail, and needed a fix to the `classical` tactic in the standard library: - [x] depends on: https://github.com/leanprover/lean4/pull/10332 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) maintainer-merge t-meta 10/0 MathlibTest/TacticAnalysis.lean 1 6 ['Vierkantor', 'github-actions', 'grunweg', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] adamtopaz
assignee:adamtopaz
4-62475
4 days ago
12-27893
12 days ago
14-34787
14 days
29513 grunweg
author:grunweg
fix(lint-style): parse linter options and load environment extensions correctly Parse options and load linter set extension correctly. This fixes two issues: - We never called the `toOptions` function that parses Lakefile options into a `Lean.Options` structure: the function we use instead is only meant for command-line options and doesn't handle the `weak.` prefix correctly. - The way we load linter sets was incorrect: `withImportModules` stopped updating environment extensions since [lean4#6325](https://github.com/leanprover/lean4/pull/6325), and that is exactly what we use to store linter sets. At the time of writing, `importModules` might be a suitable replacement (but this is not very safe, and not documented to be stable). Instead, write a small elaborator returning the environment at the point of elaboration, and use that instead. --- - [x] depends on: #29584 - [x] depends on: #29585 - [x] depends on: #29586 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) maintainer-merge t-meta 28/12 scripts/lint-style.lean 1 13 ['Vierkantor', 'adomani', 'github-actions', 'grunweg', 'mathlib4-dependent-issues-bot'] dwrensha
assignee:dwrensha
4-62474
4 days ago
12-30065
12 days ago
21-16466
21 days
30038 JovanGerb
author:JovanGerb
feat(push): `@[push]` annotations for `fun` This PR adds the annotations for the tactics `push fun _ ↦ _` and `pull fun _ ↦ _` and the simprocs `pushFun` and `pullFun`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) 28/6 Mathlib/Algebra/Notation/Pi/Defs.lean,Mathlib/Data/Nat/Cast/Basic.lean,Mathlib/Order/Lattice.lean,MathlibTest/push.lean 4 1 ['github-actions'] j-loreaux
assignee:j-loreaux
4-62470
4 days ago
11-66515
11 days ago
11-66492
11 days
30042 JovanGerb
author:JovanGerb
feat(push): `@[push]` attributes for `∈` in `Set`, `Finset` and `Multiset` This PR adds `@[push]` annotations for the membership relations, for `Set`, `Finset` and `Multiset`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) 169/104 Mathlib/Algebra/BigOperators/Group/Finset/Basic.lean,Mathlib/Algebra/Group/Pointwise/Finset/Basic.lean,Mathlib/Algebra/Group/Pointwise/Set/Basic.lean,Mathlib/Algebra/Group/Pointwise/Set/ListOfFn.lean,Mathlib/Algebra/Order/Group/Multiset.lean,Mathlib/Data/DFinsupp/Interval.lean,Mathlib/Data/Finmap.lean,Mathlib/Data/Finset/BooleanAlgebra.lean,Mathlib/Data/Finset/Dedup.lean,Mathlib/Data/Finset/Defs.lean,Mathlib/Data/Finset/Disjoint.lean,Mathlib/Data/Finset/Filter.lean,Mathlib/Data/Finset/Image.lean,Mathlib/Data/Finset/Insert.lean,Mathlib/Data/Finset/Lattice/Basic.lean,Mathlib/Data/Finset/Lattice/Fold.lean,Mathlib/Data/Finset/Pi.lean,Mathlib/Data/Finset/Powerset.lean,Mathlib/Data/Finset/Range.lean,Mathlib/Data/Finset/SDiff.lean,Mathlib/Data/Finset/Sigma.lean,Mathlib/Data/Finset/Sum.lean,Mathlib/Data/Finset/Sups.lean,Mathlib/Data/Finset/Union.lean,Mathlib/Data/Fintype/Defs.lean,Mathlib/Data/Multiset/AddSub.lean,Mathlib/Data/Multiset/Antidiagonal.lean,Mathlib/Data/Multiset/Bind.lean,Mathlib/Data/Multiset/Dedup.lean,Mathlib/Data/Multiset/Defs.lean,Mathlib/Data/Multiset/Filter.lean,Mathlib/Data/Multiset/FinsetOps.lean,Mathlib/Data/Multiset/MapFold.lean,Mathlib/Data/Multiset/Pi.lean,Mathlib/Data/Multiset/Range.lean,Mathlib/Data/Multiset/Replicate.lean,Mathlib/Data/Multiset/Sort.lean,Mathlib/Data/Multiset/Sum.lean,Mathlib/Data/Multiset/UnionInter.lean,Mathlib/Data/Multiset/ZeroCons.lean,Mathlib/Data/Set/Basic.lean,Mathlib/Data/Set/Insert.lean,Mathlib/Data/Set/Operations.lean,Mathlib/Order/Interval/Finset/Defs.lean,Mathlib/Order/Interval/Multiset.lean,Mathlib/Order/Interval/Set/Defs.lean,Mathlib/Order/SetNotation.lean,MathlibTest/push.lean 48 1 ['github-actions'] EtienneC30
assignee:EtienneC30
4-62469
4 days ago
11-63561
11 days ago
11-63538
11 days
30225 NotWearingPants
author:NotWearingPants
feat(Combinatorics/SimpleGraph/Walk): `p.getVert` and `p.support.get` have the same range --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-combinatorics 8/0 Mathlib/Combinatorics/SimpleGraph/Walk.lean 1 1 ['github-actions'] nobody
4-61649
4 days ago
4-61663
4 days ago
4-61704
4 days
30232 NotWearingPants
author:NotWearingPants
feat(Combinatorics/SimpleGraph/Connectivity/Subgraph): add `ConnectedComponent.toSubgraph` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-combinatorics easy 17/0 Mathlib/Combinatorics/SimpleGraph/Connectivity/Subgraph.lean 1 2 ['NotWearingPants', 'github-actions'] nobody
4-40494
4 days ago
4-54177
4 days ago
4-54217
4 days
25183 YaelDillies
author:YaelDillies
feat: convolution product on linear maps from a coalgebra to an algebra Construct the ring structure on linear maps `C → A` where `C` is a coalgebra and `A` an algebra, where multiplication is given by `(f * g)(x) = ∑ f x₍₁₎ * g x₍₂₎` in Sweedler notation or ``` | μ | | / \ f * g = f g | | \ / δ | ``` diagrammatically, where `μ` stands for multiplication and `δ` for comultiplication. [Zulip](https://leanprover.zulipchat.com/#narrow/channel/217875-Is-there-code-for-X.3F/topic/.60Mul.60.20instance.20on.20algebra.20homomorphisms.20from.20monoid.20algebra) From Toric Co-authored-by: Michał Mrugała Co-authored-by: Yunzhou Xie --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) toric t-algebra
label:t-algebra$
261/10 Mathlib.lean,Mathlib/Algebra/Algebra/Bilinear.lean,Mathlib/Algebra/Algebra/Defs.lean,Mathlib/LinearAlgebra/TensorProduct/Basic.lean,Mathlib/RingTheory/Coalgebra/Basic.lean,Mathlib/RingTheory/Coalgebra/Convolution.lean,Mathlib/RingTheory/Regular/RegularSequence.lean 7 88 ['YaelDillies', 'erdOne', 'eric-wieser', 'github-actions', 'kbuzzard', 'smorel394', 'themathqueen'] kbuzzard
assignee:kbuzzard
4-40383
4 days ago
42-31240
1 month ago
136-83687
136 days
26457 AntoineChambert-Loir
author:AntoineChambert-Loir
feat(Mathlib/GroupTheory/Perm/MaximalSubgroups): maximal subgroups of the permutation group * `Equiv.Perm.isCoatom_stabilizer`: when `s : Set α` is not empty, nor its complementary subset, and if the cardinality of `s` is not half of that of `α`, then `MulAction.stabilizer (Equiv.Perm α) s` is a maximal subgroup of the symmetric group `Equiv.Perm α`. This is the *intransitive case* of the O'Nan-Scott classification. ## TODO * Appplication to primitivity of the action of `Equiv.Perm α` on finite combinations of `α`. * Finish the classification --- - [ ] depends on: #26282 - [x] depends on: #26281 - [x] depends on: #26280 - [x] depends on: #26279 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-group-theory 525/2 Mathlib.lean,Mathlib/GroupTheory/GroupAction/Jordan.lean,Mathlib/GroupTheory/GroupAction/MultiplePrimitivity.lean,Mathlib/GroupTheory/GroupAction/SubMulAction/OfFixingSubgroup.lean,Mathlib/GroupTheory/GroupAction/SubMulAction/OfStabilizer.lean,Mathlib/GroupTheory/Perm/Cycle/Basic.lean,Mathlib/GroupTheory/Perm/MaximalSubgroups.lean,docs/references.bib 8 n/a ['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] nobody
4-34534
4 days ago
unknown
unknown
26720 vlad902
author:vlad902
feat(SimpleGraph): lemmas relating edges and darts to the support Useful lemmas to make it easier to pass between the support/edges/darts of a walk. - [x] depends on: #25812 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-combinatorics 27/0 Mathlib/Combinatorics/SimpleGraph/Walk.lean 1 9 ['b-mehta', 'github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'vlad902'] b-mehta
assignee:b-mehta
4-24208
4 days ago
4-24208
4 days ago
27-50724
27 days
30085 riccardobrasca
author:riccardobrasca
feat: add Mathlib.RingTheory.RootsOfUnity.Units We abb basic results about cyclotomic units. From `flt-regular`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory t-algebra t-number-theory
label:t-algebra$
124/0 Mathlib.lean,Mathlib/RingTheory/RootsOfUnity/CyclotomicUnits.lean 2 18 ['faenuccio', 'github-actions', 'riccardobrasca'] faenuccio
assignee:faenuccio
4-21655
4 days ago
4-22131
4 days ago
5-13782
5 days
30136 vlad902
author:vlad902
feat(SimpleGraph): lemmas characterizing graphs that are not complete/empty Two helper lemmas that I've found useful in several other PRs that characterize graphs that are neither complete nor empty. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-combinatorics 8/0 Mathlib/Combinatorics/SimpleGraph/Basic.lean 1 1 ['github-actions'] nobody
4-13659
4 days ago
6-81816
6 days ago
6-81853
6 days
29833 vlad902
author:vlad902
feat(Set): helper lemmas about set cardinality A few lemmas I needed in formalizing Dilworth's theorem and vertex covers. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data 19/0 Mathlib/Data/Set/Card.lean 1 13 ['Ruben-VandeVelde', 'github-actions', 'j-loreaux', 'mathlib4-merge-conflict-bot', 'themathqueen', 'vlad902'] nobody
4-13657
4 days ago
4-72969
4 days ago
19-22899
19 days
30245 vlad902
author:vlad902
feat(Set): finite cardinality iff `[Finite]` Add a lemma making it easy to derive `Finite α` from `ENat.card α < ⊤`. Note that immediately above, the following three lemmas are defined: ```lean @[simp high] theorem card_eq_top_of_infinite [Infinite α] : card α = ⊤ := by ... @[simp] lemma card_eq_top : card α = ⊤ ↔ Infinite α := by ... @[simp] theorem card_lt_top_of_finite [Finite α] : card α < ⊤ := by ... ``` `card_lt_top` is the analog of `card_eq_top`, so symmetry implies that `card_lt_top_of_finite` should be marked `@[simp high]` and `card_lt_top` should be marked `@[simp]`. I find this use of `@[simp]` a bit surprising so I wanted to highlight this to reviewers. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-set-theory 3/1 Mathlib/SetTheory/Cardinal/Finite.lean 1 1 ['github-actions'] nobody
4-12818
4 days ago
4-12820
4 days ago
4-12860
4 days
30047 ooovi
author:ooovi
feat(Combinatorics/SimpleGraph): edge labellings Add edge labellings for `SimpleGraph` as well as some basic lemmata. --- This is mostly a cleaned up part of @b-mehta's lean4 port of their [formalisation of an exponentially better upper bound on Ramsey numbers ](https://github.com/b-mehta/ExponentialRamsey/). I need these definitions for another project on Ramsey theory. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-combinatorics 234/3 Mathlib.lean,Mathlib/Combinatorics/SimpleGraph/Basic.lean,Mathlib/Combinatorics/SimpleGraph/EdgeLabelling.lean,Mathlib/Combinatorics/SimpleGraph/Regularity/Increment.lean,Mathlib/Combinatorics/SimpleGraph/Triangle/Counting.lean 5 45 ['YaelDillies', 'b-mehta', 'github-actions', 'ooovi', 'vlad902'] nobody
4-10798
4 days ago
4-10798
4 days ago
9-21259
9 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 30/0 Mathlib.lean,Mathlib/Algebra/Order/Group/Unbundled/Abs.lean,Mathlib/Data/Finset/RangeDistance.lean 3 2 ['github-actions', 'mans0954'] alreadydone
assignee:alreadydone
4-2846
4 days ago
66-29478
2 months ago
107-38884
107 days
30248 dwrensha
author:dwrensha
chore: remove obsolete NormDigits namespace In Lean 3, `nat.digits m n` with concrete numbers `m` `n` could be normalized via `norm_num`. [The logic enabling that](https://github.com/leanprover-community/mathlib3/blob/65a1391a0106c9204fe45bc73a039f056558cb83/src/data/nat/digits.lean#L599-L678) was partially ported over to Lean 4 in the `NormDigits` namespace, but never was completed. Independently, simprocs as introduced in Lean v4.6.0 made it so that `simp [Nat.digits, Nat.digitsAux]` could normalize `Nat.digits m n` without any need for the special `NormDigits` code. More recently, #25864 made it so that just plain `rfl` can normalize `Nat.digits m n` (but note that a revert PR has been proposed in #30246). Therefore, the `NormDigits` namespace is no longer relevent and should be deleted. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data 0/102 Mathlib/Data/Nat/Digits/Defs.lean 1 1 ['github-actions'] nobody
4-441
4 days ago
4-451
4 days ago
4-490
4 days
26885 pechersky
author:pechersky
feat(Topology/ValuativeRel): ValuativeTopology 𝒪[K] and even when not a field, `ValuativeRel 𝒪[K]` This is an example of something achievable with the new declarations that wasn't possible with Valued Such that we can discuss the valuations on the subring without always using coercions But to achieve this, one needs some juggling of the value groups --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) - [x] depends on: #26834 - [ ] depends on : #30135 t-algebra t-topology t-number-theory
label:t-algebra$
73/0 Mathlib/RingTheory/Valuation/ValuativeRel/Basic.lean,Mathlib/Topology/Algebra/Valued/ValuativeRel.lean 2 9 ['erdOne', 'github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'pechersky'] alreadydone
assignee:alreadydone
3-80099
3 days ago
42-82842
1 month ago
92-67849
92 days
30244 harahu
author:harahu
feat: misc. generalizations by LLM All found by asking Codex to search for low-hanging generalization opportunities. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
77/70 Mathlib/Algebra/Algebra/Operations.lean 1 13 ['github-actions', 'harahu', 'kckennylau', 'themathqueen'] nobody
3-70468
3 days ago
4-13568
4 days ago
4-13607
4 days
29758 NotWearingPants
author:NotWearingPants
feat(RingTheory/RootsOfUnity): exp(pi * i * q) is a root of unity for rational q --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory new-contributor 28/1 Mathlib/RingTheory/RootsOfUnity/Complex.lean 1 5 ['NotWearingPants', 'Ruben-VandeVelde', 'github-actions', 'kckennylau'] chrisflav
assignee:chrisflav
3-69006
3 days ago
20-67311
20 days ago
20-74312
20 days
30252 harahu
author:harahu
feat(Algebra): generalize isSMulRegular_iff_torsionBy_eq_bot Relax an assumption. --- Found by asking OpenAI Codex to search for low-hanging generalization opportunities. I don't have any usage in mind. Just wanted to explore what Codex would find. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
4/2 Mathlib/Algebra/Module/Torsion.lean 1 2 ['github-actions', 'themathqueen'] nobody
3-68136
3 days ago
3-82934
3 days ago
3-82978
3 days
30259 erdOne
author:erdOne
feat(Valuation): uniformizer of discrete valuation --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory 31/0 Mathlib/RingTheory/Valuation/ValuativeRel/Basic.lean 1 2 ['github-actions', 'pechersky'] nobody
3-63826
3 days ago
3-65187
3 days ago
3-65226
3 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
label:t-algebra$
211/27 Mathlib.lean,Mathlib/Analysis/Normed/ValuativeRel.lean,Mathlib/Topology/Algebra/Valued/ValuativeRel.lean 3 33 ['ADedecker', 'adamtopaz', 'erdOne', 'github-actions', 'kbuzzard', 'kckennylau', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'pechersky'] kbuzzard
assignee:kbuzzard
3-62674
3 days ago
57-8991
1 month ago
93-74707
93 days
27290 themathqueen
author:themathqueen
feat: `Star`, `StarAddMonoid`, and `StarModule` instances for tensor products This pr defines the `Star`, `StarAddMonoid` and `StarModule` instances on tensor product spaces. And the `StarRing` instance. --- - [x] depends on: #27288 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
55/0 Mathlib.lean,Mathlib/LinearAlgebra/TensorProduct/Star.lean,Mathlib/RingTheory/TensorProduct/Basic.lean 3 3 ['github-actions', 'mathlib4-dependent-issues-bot', 'themathqueen'] alreadydone
assignee:alreadydone
3-62503
3 days ago
11-7112
11 days ago
11-7927
11 days
29589 grunweg
author:grunweg
feat: add mfderiv_prod and mfderiv_prodMap Part of my bordism theory project: these will be needed for https://github.com/leanprover-community/mathlib4/pull/22059. Updated version of #22642. --- - [x] depends on: #30049 for ease of reviewing [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-differential-geometry 81/0 Mathlib/Analysis/Calculus/FDeriv/Prod.lean,Mathlib/Geometry/Manifold/IsManifold/ExtChartAt.lean,Mathlib/Geometry/Manifold/MFDeriv/SpecificFunctions.lean 3 2 ['github-actions', 'mathlib4-dependent-issues-bot'] hrmacbeth
assignee:hrmacbeth
3-62501
3 days ago
11-21499
11 days ago
11-21506
11 days
30009 ADedecker
author:ADedecker
chore: rename `IsTopologicalGroup.toUniformSpace` to `IsTopologicalGroup.rightUniformSpace` I have plans to finally do left and right uniformities properly, but I'd like to do some of the remaining before the fact to ease review. I also take this opportunity to remove a duplication of private lemmas `extend_Z_bilin_aux` and `extend_Z_bilin_key`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-topology 104/184 Mathlib/Analysis/CStarAlgebra/Matrix.lean,Mathlib/Analysis/LocallyConvex/Bounded.lean,Mathlib/Analysis/LocallyConvex/WithSeminorms.lean,Mathlib/Analysis/Normed/Group/Quotient.lean,Mathlib/Analysis/Normed/Operator/Compact.lean,Mathlib/Analysis/NormedSpace/Multilinear/Basic.lean,Mathlib/Analysis/Seminorm.lean,Mathlib/Analysis/SpecialFunctions/Bernstein.lean,Mathlib/Topology/Algebra/Group/Defs.lean,Mathlib/Topology/Algebra/InfiniteSum/Group.lean,Mathlib/Topology/Algebra/InfiniteSum/NatInt.lean,Mathlib/Topology/Algebra/IsUniformGroup/Basic.lean,Mathlib/Topology/Algebra/IsUniformGroup/Defs.lean,Mathlib/Topology/Algebra/Module/Alternating/Topology.lean,Mathlib/Topology/Algebra/Module/FiniteDimension.lean,Mathlib/Topology/Algebra/Module/LocallyConvex.lean,Mathlib/Topology/Algebra/Module/Multilinear/Topology.lean,Mathlib/Topology/Algebra/Module/StrongTopology.lean,Mathlib/Topology/Algebra/Nonarchimedean/AdicTopology.lean,Mathlib/Topology/Algebra/UniformFilterBasis.lean,Mathlib/Topology/Algebra/Valued/ValuationTopology.lean,Mathlib/Topology/Algebra/Valued/ValuativeRel.lean,Mathlib/Topology/ContinuousMap/Algebra.lean 23 3 ['github-actions', 'mathlib4-merge-conflict-bot', 'plp127'] PatrickMassot
assignee:PatrickMassot
3-62499
3 days ago
10-85289
10 days ago
12-12295
12 days
30029 ADedecker
author:ADedecker
feat: define IsRightUniformGroup and IsLeftUniformGroup This mostly contains the definition and additional documentation. Future PRs will take care of expanding the theory, and proving in particular that `IsUniformGroup` is precisely the conjuction of these two typeclasses. --- - [x] depends on: #30025 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-topology 199/36 Mathlib/Topology/Algebra/IsUniformGroup/Basic.lean,Mathlib/Topology/Algebra/IsUniformGroup/Defs.lean 2 9 ['ADedecker', 'github-actions', 'leanprover-bot', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] PatrickMassot
assignee:PatrickMassot
3-62498
3 days ago
10-85167
10 days ago
11-9999
11 days
30039 JovanGerb
author:JovanGerb
feat(push): `@[push]` annotations for `Real.log` This PR adds `push` annotations, and tests for `Real.log`. It also updates the `#push` and `#pull` commands so that they can take a discharger, and can take any head. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) 45/18 Mathlib/Analysis/SpecialFunctions/Log/Basic.lean,Mathlib/Analysis/SpecialFunctions/Pow/Real.lean,Mathlib/Tactic/Push.lean,MathlibTest/push.lean 4 1 ['github-actions'] kex-y
assignee:kex-y
3-62497
3 days ago
11-66452
11 days ago
11-66429
11 days
30246 dwrensha
author:dwrensha
make Nat.digits use well-founded recursion once again #25864 made `Nat.digits` structurally recursive, which has some benefits. In doing so, however, it added significant complexity. As brought up in [this zulip thread](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/structural.20recursion.20instead.20of.20well.20founded/near/543172385), on the balance that PR might not be considered an improvement. The present PR reverts that change (but keeps a code golf that was bundled with it). Note that recent improvements to core Lean mean that `simp` can handle the structurally recursive version without a problem: ```lean example : digits 10 123456789 = [9,8,7,6,5,4,3,2,1] := by simp [digits, digitsAux] ``` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data 7/45 Mathlib/Data/Nat/Digits/Defs.lean 1 7 ['alreadydone', 'dwrensha', 'github-actions', 'plp127'] nobody
3-62301
3 days ago
4-4430
4 days ago
4-4463
4 days
30261 NotWearingPants
author:NotWearingPants
feat(Algebra/Ring/Basic): add `a / -b = -a / b` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-algebra
label:t-algebra$
5/3 Mathlib/Algebra/Ring/Basic.lean 1 1 ['github-actions'] nobody
3-61855
3 days ago
3-61867
3 days ago
3-61905
3 days
28557 ShreckYe
author:ShreckYe
feat(Data/Nat/Factorization): some results on equality of powers of naturals proved from factorization I came across some math olympiad problems in number theory that could benefit from these theorems, expecially those on the prime power equality `p ^ m = a ^ n`. A specialized `eq_of_factorization_eq'` is added BTW to help with proof search. t-data 100/0 Mathlib/Data/Nat/Factorization/Basic.lean,Mathlib/Data/Nat/Factorization/Defs.lean,Mathlib/Data/Nat/Factorization/PrimePow.lean 3 13 ['Ruben-VandeVelde', 'ShreckYe', 'github-actions'] pechersky
assignee:pechersky
3-50606
3 days ago
3-52290
3 days ago
50-46437
50 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 45/5 Mathlib/NumberTheory/ArithmeticFunction.lean 1 13 ['MichaelStollBayreuth', 'NotWearingPants', 'b-mehta', 'eric-wieser', 'github-actions', 'sun123zxy'] MichaelStollBayreuth
assignee:MichaelStollBayreuth
3-24187
3 days ago
50-49666
1 month ago
50-50630
50 days
30264 pechersky
author:pechersky
feat(RingTheory/RootsOfUnity): `rootsOfUnity_inf_rootsOfUnity` towards torsion subgroup as union of roots of unity of prime powers --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory easy 12/0 Mathlib/RingTheory/RootsOfUnity/Basic.lean 1 1 ['github-actions'] nobody
3-18487
3 days ago
3-58395
3 days ago
3-58436
3 days
30273 NotWearingPants
author:NotWearingPants
feat(NumberTheory/SumTwoSquares): it is decidable whether a number is the sum of two squares Add a `Decidable` instance for the already proven theorem of being the sum of two squares. Try `#eval Finset.range 50 |>.filter (∃ x y, · = x ^ 2 + y ^ 2)` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-number-theory 7/0 Mathlib/NumberTheory/SumTwoSquares.lean 1 1 ['github-actions'] nobody
3-9506
3 days ago
3-9518
3 days ago
3-9560
3 days
28484 euprunin
author:euprunin
chore(Data): deprecate `toReal_eq_toReal`, `count_eq_of_nodup` and `smul_mat_cons` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data 16/25 Archive/Wiedijk100Theorems/BallotProblem.lean,Mathlib/Data/ENNReal/Real.lean,Mathlib/Data/List/Dedup.lean,Mathlib/Data/List/FinRange.lean,Mathlib/Data/List/Nodup.lean,Mathlib/LinearAlgebra/Matrix/Notation.lean,Mathlib/MeasureTheory/Function/ConditionalExpectation/Real.lean,Mathlib/MeasureTheory/Function/L2Space.lean,Mathlib/MeasureTheory/Integral/Layercake.lean,Mathlib/Probability/Distributions/Exponential.lean,Mathlib/Probability/Independence/Integration.lean,Mathlib/Probability/Kernel/Condexp.lean,Mathlib/Topology/Instances/ENNReal/Lemmas.lean 13 13 ['b-mehta', 'bryangingechen', 'euprunin', 'github-actions', 'leanprover-bot', 'leanprover-community-mathlib4-bot', 'mathlib4-merge-conflict-bot', 'pechersky', 'qawbecrdtey'] pechersky
assignee:pechersky
3-5280
3 days ago
3-5280
3 days ago
52-35150
52 days
28950 Vierkantor
author:Vierkantor
fix(TacticAnalysis): remove syntax range check In #28802 we discovered the tactic analysis framework does not fire on declarations using `where` clauses. The reason is that `def foo where ...` gets turned into `def foo := { ... }`, and the `{ ... }` syntax is assigned a range outside of the `where ...` syntax; this causes the syntax range check to omit the whole declaration body. Moreover, [Verso involves pieces of syntax without any range at all](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Possible.20Verso.E2.80.93Mathlib.20conflict/with/543352839). So the range of a piece of syntax is essentially meaningless and we should not check it at all. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-meta 18/11 Mathlib/Tactic/TacticAnalysis.lean,MathlibTest/TacticAnalysis.lean 2 3 ['Vierkantor', 'github-actions', 'thorimur'] robertylewis
assignee:robertylewis
3-4781
3 days ago
44-30554
1 month ago
44-30531
44 days
30223 NotWearingPants
author:NotWearingPants
feat(Data/List/Nodup): `get` is bijective iff `count = 1` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data maintainer-merge new-contributor 9/0 Mathlib/Data/List/Nodup.lean 1 2 ['Ruben-VandeVelde', 'github-actions'] nobody
2-85736
2 days ago
2-85736
2 days ago
4-64595
4 days
30212 tb65536
author:tb65536
feat(Algebra/Polynomial/Factors): Introduce predicate and basic API This PR introduces a predicate `Polynomial.Factors` that generalizes `Polynomial.Splits` beyond fields. This PR contains the definition of `Polynomial.Factors` along with most of API for `Polynomial.Splits`. The end goal is to either redefine `Polynomial.Splits` in terms of `Polynomial.Factors` or deprecate `Polynomial.Splits` entirely. Zulip discussion: https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Generalizing.20.60Polynomial.2ESplits.60.20to.20rings --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory t-algebra
label:t-algebra$
293/1 Mathlib.lean,Mathlib/Algebra/Polynomial/Factors.lean,Mathlib/Algebra/Polynomial/Monic.lean,Mathlib/Algebra/Polynomial/Splits.lean 4 26 ['github-actions', 'kckennylau', 'tb65536'] nobody
2-83909
2 days ago
4-71966
4 days ago
4-71945
4 days
29517 pechersky
author:pechersky
feat(RingTheory/Torsion): torsion = union of roots of unity with additional API for Associates and rootsOfUnity sups --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) - [x] depends on: #29988 - [x] depends on: #29989 - [x] depends on: #29990 - [x] depends on: #29991 t-algebra
label:t-algebra$
156/8 Mathlib.lean,Mathlib/RingTheory/RootsOfUnity/Basic.lean,Mathlib/RingTheory/RootsOfUnity/PrimitiveRoots.lean,Mathlib/RingTheory/Torsion.lean 4 10 ['chrisflav', 'github-actions', 'kckennylau', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'pechersky'] chrisflav
assignee:chrisflav
2-77981
2 days ago
2-78002
2 days ago
15-42822
15 days
28389 euprunin
author:euprunin
chore(Algebra/Group/Subgroup): deprecate `sup_subgroupOf_eq` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
9/13 Mathlib/Algebra/Group/Subgroup/Ker.lean,Mathlib/GroupTheory/PGroup.lean 2 4 ['Ruben-VandeVelde', 'chrisflav', 'euprunin', 'github-actions'] chrisflav
assignee:chrisflav
2-77410
2 days ago
2-77869
2 days ago
26-28767
26 days
28422 euprunin
author:euprunin
chore(Data/Fin): deprecate `Fin.mul_one'`, `Fin.one_mul'`, `Fin.mul_zero'` and `Fin.zero_mul'` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data 8/15 Mathlib/Data/Fin/Basic.lean,Mathlib/Data/ZMod/Defs.lean 2 3 ['eric-wieser', 'euprunin', 'github-actions'] nobody
2-77351
2 days ago
2-82659
2 days ago
11-7036
11 days
30285 kckennylau
author:kckennylau
chore: document Spec(R) notation in docstring of Spec #30272 changed the `Spec(R)` notation to scoped, so I am including this new information in the docstring of `AlgebraicGeometry.Spec`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebraic-geometry 13/0 Mathlib/AlgebraicGeometry/Scheme.lean 1 1 ['github-actions'] nobody
2-69408
2 days ago
2-70665
2 days ago
2-70701
2 days
29507 zhuyizheng
author:zhuyizheng
feat(MeasureTheory): derivative integrable functions Part of originally planned #29092. We prove that: * If `f` is monotone on `a..b`, then `f'` is interval integrable on `a..b`. * If `f` has bounded variation on `a..b`, then `f'` is interval integrable on `a..b`. * If `f` is absolutely continuous on `a..b`, then `f'` exists a.e. on `a..b` and is interval integrable on `a..b`. --- - [x] depends on: #29504 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-measure-probability 172/1 Mathlib.lean,Mathlib/Analysis/Calculus/Deriv/Slope.lean,Mathlib/MeasureTheory/Function/AbsolutelyContinuous.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral/DerivIntegrable.lean,Mathlib/MeasureTheory/Integral/Lebesgue/Add.lean 5 3 ['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] nobody
2-65993
2 days ago
3-16811
3 days ago
3-17112
3 days
26985 agjftucker
author:agjftucker
feat(Analysis/Calculus/Implicit): define implicitFunOfProdDomain This PR continues the work from #16743. Original PR: https://github.com/leanprover-community/mathlib4/pull/16743 --- - [x] depends on: #28352 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-analysis 107/4 Mathlib/Analysis/Calculus/Implicit.lean 1 3 ['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] hrmacbeth
assignee:hrmacbeth
2-62502
2 days ago
10-36590
10 days ago
10-38169
10 days
27228 themathqueen
author:themathqueen
feat: defining the inner product on tensor products This defines the inner product on tensor product spaces. Also defines `OrthonormalBasis.tensorProduct`. The implementation is based on [here](https://github.com/ocfnash/lean-shannon-lovasz/blob/e63e535599ffb3c2a7e995e1621847693dd68fab/src/to_mathlib/analysis/inner_product_space/tensor_product.lean#L404) (by @jjaassoonn), which defines the inner product on real tensor product spaces. The exact same implementation also applies for the general case. Closes #6020 --- - [x] depends on: #27288 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra t-analysis
label:t-algebra$
281/0 Mathlib.lean,Mathlib/Analysis/InnerProductSpace/TensorProduct.lean,Mathlib/LinearAlgebra/FiniteDimensional/Basic.lean,Mathlib/LinearAlgebra/TensorProduct/Basis.lean 4 5 ['eric-wieser', 'github-actions', 'mathlib4-dependent-issues-bot', 'themathqueen'] YaelDillies
assignee:YaelDillies
2-62501
2 days ago
11-2912
11 days ago
11-4212
11 days
28812 yury-harmonic
author:yury-harmonic
feat(PNat/Factors): add attrs and lemmas --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data new-contributor 42/0 Mathlib/Data/PNat/Factors.lean 1 1 ['github-actions'] pechersky
assignee:pechersky
2-62499
2 days ago
47-11865
1 month ago
47-11898
47 days
29309 LLaurance
author:LLaurance
feat(Combinatorics/SimpleGraph): Nontrivial connected graph contains a vertex that leaves the graph connected if removed This shows that any nontrivial connected graph contains a vertex that, when removed, leaves the graph connected. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) large-import new-contributor t-combinatorics 156/10 Mathlib/Combinatorics/SimpleGraph/Acyclic.lean,Mathlib/Combinatorics/SimpleGraph/Connectivity/Connected.lean,Mathlib/Combinatorics/SimpleGraph/Connectivity/Subgraph.lean,Mathlib/Combinatorics/SimpleGraph/Subgraph.lean,Mathlib/Combinatorics/SimpleGraph/Walk.lean 5 2 ['github-actions', 'mathlib4-merge-conflict-bot'] YaelDillies
assignee:YaelDillies
2-62498
2 days ago
10-24449
10 days ago
31-29066
31 days
29425 pechersky
author:pechersky
feat(NumberTheory/Padics/Torsion): `HasEnoughRootsOfUnity ℤ_[p] (p - 1)` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) - [x] depends on: #29403 - [x] depends on: #29404 - [x] depends on: #29405 - [x] depends on: #29408 - [x] depends on: #29424 t-ring-theory 179/0 Mathlib.lean,Mathlib/NumberTheory/Padics/Torsion.lean,Mathlib/RingTheory/ZMod/Torsion.lean 3 3 ['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] erdOne
assignee:erdOne
2-62497
2 days ago
10-7367
10 days ago
10-8000
10 days
29642 pechersky
author:pechersky
chore(RingTheory/AdicValuation,LaurentSeries): switch to `WithZero.exp` instead of coercions of `Multiplicative.ofAdd` as requested at https://github.com/leanprover-community/mathlib4/pull/27339#issuecomment-3285102305 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory 58/68 Mathlib/FieldTheory/RatFunc/AsPolynomial.lean,Mathlib/NumberTheory/NumberField/FinitePlaces.lean,Mathlib/RingTheory/DedekindDomain/AdicValuation.lean,Mathlib/RingTheory/DedekindDomain/SelmerGroup.lean,Mathlib/RingTheory/LaurentSeries.lean 5 3 ['github-actions', 'mathlib4-merge-conflict-bot'] mattrobball
assignee:mattrobball
2-62496
2 days ago
10-15291
10 days ago
18-25661
18 days
29706 kim-em
author:kim-em
feat: add piCongrSigmaFiber and piCongrFiberwise equivalences ## Summary Add two new equivalence functions for working with fibers and sigma types: - `Equiv.piCongrSigmaFiber`: transforms between functions on sigma fibers and regular pi types - `Equiv.piCongrFiberwise`: lifts fiber-wise equivalences to product equivalences These functions are from the FLT (Fermat's Last Theorem) project and are useful for manipulating dependent function types indexed by fibers of a function. ## Details The new definitions allow for elegant transformations between: 1. Functions defined on sigma types representing fibers of a function 2. Regular dependent functions These are particularly useful in algebraic contexts where one needs to work with products indexed by fibers. ## Context This PR was prepared by Claude (Claude Code) based on the following prompt: > "Please read FLT/Mathlib/Logic/Equiv/Basic.lean, and also the corresponding file in the Mathlib repository. Please prepare a PR to Mathlib containing this content, putting it at an appropriate point in the corresponding Mathlib file. Make sure the PR is label FLT, and write in the PR comment an explanation that the PR was prepared by Claude, including quoting the prompting." The content is sourced from `/Users/kim/projects/lean/FLT/FLT/Mathlib/Logic/Equiv/Basic.lean` in the FLT project repository. 🤖 Generated with [Claude Code](https://claude.ai/code) FLT t-logic 39/0 Mathlib/Logic/Equiv/Basic.lean 1 5 ['Ruben-VandeVelde', 'github-actions', 'kim-em'] fpvandoorn
assignee:fpvandoorn
2-62495
2 days ago
23-17831
23 days ago
23-34039
23 days
29969 smmercuri
author:smmercuri
refactor: use isometry extensions for completions at infinite places of number fields The API for `InfinitePlace.Completion` currently makes use of abstract results defined on absolute values, which all depend on the hypothesis of the form `∀ x, ‖f x‖ = v x`. This is equivalent to `f` being an isometry, and so many of these results can be bypassed and deprecated by using `Isometry.completion_extension` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) 72/47 Mathlib/Analysis/Normed/Field/WithAbs.lean,Mathlib/NumberTheory/NumberField/AdeleRing.lean,Mathlib/NumberTheory/NumberField/InfinitePlace/Completion.lean,Mathlib/Topology/MetricSpace/Completion.lean 4 1 ['github-actions'] TwoFX
assignee:TwoFX
2-62493
2 days ago
14-7735
14 days ago
14-7720
14 days
30037 linesthatinterlace
author:linesthatinterlace
feat: Fin.find update We currently define `Fin.find` in a way that is redundant (in the sense that it is just equivalent to `Fin.find?` in batteries). This PR replaces it with a definition that works closer to `Nat.find`, and links the new definition of `Fin.find` to `Fin.find?` in the natural way. --- - [ ] depends on: batteries#1431 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) 137/103 Mathlib/Data/Fin/Tuple/Basic.lean,lake-manifest.json 2 6 ['github-actions', 'linesthatinterlace', 'llllvvuu', 'mathlib4-merge-conflict-bot'] adamtopaz
assignee:adamtopaz
2-62491
2 days ago
10-3342
10 days ago
11-59248
11 days
29449 mitchell-horner
author:mitchell-horner
feat(Combinatorics/SimpleGraph): add Turán density related theorems Refactors `tendsto_turanDensity` and implements `turanDensity_eq_sInf` and `isContained_of_card_edgeFinset` (theorems that are common in proofs involving Turán density). --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-combinatorics 51/14 Mathlib/Combinatorics/SimpleGraph/Extremal/TuranDensity.lean 1 12 ['YaelDillies', 'github-actions', 'mitchell-horner'] YaelDillies
assignee:YaelDillies
2-57935
2 days ago
3-47365
3 days ago
29-65439
29 days
27974 smmercuri
author:smmercuri
feat: `Field`, `FiniteDimensional` and `Algebra.IsSeparable` instances for `WithAbs` This PR continues the work from #24870. Original PR: https://github.com/leanprover-community/mathlib4/pull/24870 large-import t-analysis 14/1 Mathlib/Analysis/Normed/Field/WithAbs.lean 1 3 ['github-actions', 'j-loreaux', 'smmercuri'] j-loreaux
assignee:j-loreaux
2-34921
2 days ago
2-34921
2 days ago
13-15062
13 days
29556 joelriou
author:joelriou
feat(CategoryTheory): functors that are dense at an object Given a functor `F : C ⥤ D` and `Y : D`, we say that `F` is dense at `Y` if `Y` identifies to the colimit of all `F.obj X` for `X : C` and `f : F.obj X ⟶ Y`, i.e. the obvious natural transformation makes the identity functor of `D` a pointwise left Kan extension of `F` along `F` at `Y`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-category-theory 129/1 Mathlib.lean,Mathlib/CategoryTheory/Functor/KanExtension/DenseAt.lean,Mathlib/CategoryTheory/Functor/KanExtension/Pointwise.lean 3 4 ['github-actions', 'joelriou', 'robin-carlier'] joneugster
assignee:joneugster
2-16704
2 days ago
2-16704
2 days ago
28-4647
28 days
30238 kebekus
author:kebekus
feat: behavior of divisors when taking powers of meromorphic functions Establish the behavior of divisors when taking powers of meromorphic functions. For consistency, provide `_fun`-versions of several simple lemmas. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-analysis 119/3 Mathlib/Analysis/Meromorphic/Divisor.lean,Mathlib/Analysis/Meromorphic/FactorizedRational.lean,Mathlib/Analysis/Meromorphic/Order.lean 3 14 ['YaelDillies', 'github-actions', 'kebekus'] nobody
2-14969
2 days ago
3-29505
3 days ago
4-20210
4 days
30147 NotWearingPants
author:NotWearingPants
feat(NumberTheory/ArithmeticFunction): add some lemmas --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-number-theory 23/1 Mathlib/NumberTheory/ArithmeticFunction.lean 1 3 ['github-actions', 'kckennylau'] nobody
2-12982
2 days ago
6-59121
6 days ago
6-59154
6 days
30216 NotWearingPants
author:NotWearingPants
feat(Data/List/Basic): `get` is surjective iff every element is in the list --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data new-contributor easy 13/0 Mathlib/Data/List/Basic.lean 1 6 ['NotWearingPants', 'github-actions', 'themathqueen'] nobody
2-12181
2 days ago
4-73157
4 days ago
4-73192
4 days
30219 NotWearingPants
author:NotWearingPants
feat(Combinatorics/SimpleGraph/Paths): path iff `p.support.get` is injective --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-combinatorics easy 4/0 Mathlib/Combinatorics/SimpleGraph/Paths.lean 1 3 ['NotWearingPants', 'github-actions', 'themathqueen'] nobody
2-11408
2 days ago
4-70220
4 days ago
4-70254
4 days
30282 NotWearingPants
author:NotWearingPants
chore(Algebra/Order/Ring/Unbundled/Rat): golf --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-algebra
label:t-algebra$
10/26 Mathlib/Algebra/Order/Ring/Unbundled/Rat.lean 1 7 ['Ruben-VandeVelde', 'github-actions', 'kckennylau', 'themathqueen'] nobody
2-10858
2 days ago
2-74203
2 days ago
2-74244
2 days
30293 vlad902
author:vlad902
feat(SimpleGraph): there exists a maximal path/trail in a graph with finite edges Inspired by [this Zulip thread](https://leanprover.zulipchat.com/#narrow/channel/252551-graph-theory/topic/Help.20me.20learn.20good.20style.3A.20IsTree/near/543395218) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-combinatorics 27/1 Mathlib/Combinatorics/SimpleGraph/Paths.lean 1 2 ['github-actions', 'vlad902'] nobody
2-10808
2 days ago
2-31677
2 days ago
2-31710
2 days
30182 urkud
author:urkud
feat(Calculus): derivative of `ContinuousMultilinearMap.compContinuousLinearMap` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-analysis 136/1 Mathlib.lean,Mathlib/Analysis/Calculus/FDeriv/ContinuousMultilinearMap.lean,Mathlib/Analysis/NormedSpace/Multilinear/Basic.lean 3 1 ['github-actions'] nobody
2-6876
2 days ago
5-75128
5 days ago
5-75165
5 days
26398 ChrisHughes24
author:ChrisHughes24
feat(ModelTheory): definable functions --- Possibly this should be generalized to partial functions. I migrated the PR by hand instead of using the script. - [x] depends on: #20166 - [x] depends on: #20161 - [x] depends on: #20115 - [x] depends on: #20174 - [x] depends on: #20175 - [x] depends on: #21948 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-logic 618/0 Mathlib.lean,Mathlib/ModelTheory/FunctionalFormula.lean 2 9 ['ChrisHughes24', 'github-actions', 'kckennylau', 'mathlib4-dependent-issues-bot', 'staroperator'] fpvandoorn
assignee:fpvandoorn
2-5302
2 days ago
106-33367
3 months ago
106-33618
106 days
29352 fpvandoorn
author:fpvandoorn
refactor: simplify dictionary in fixAbbreviation * Improve capitalization algorithm: you now don't have to give entries twice in `fixAbbreviation` (now `abbreviationDict`). * The new algorithm uses the fact that we can easily find the `lowerCamelCase` name from the `UpperCamelCase` name, namely by applying `String.decapitalizeSeq`. This means that both `nameDict` and `abbreviationDict` have as input `lowerCamelCase` and as output `UpperCamelCase`. * This removes the need to especially fix `NSMul`/`ZSMul` and similar. * `abbreviationDict` still needs two entries if both `snake_case` and either `camelCase` need to be translated. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-meta 151/163 Mathlib/Tactic/ToAdditive/GuessName.lean,MathlibTest/toAdditive.lean 2 22 ['JovanGerb', 'fpvandoorn', 'github-actions', 'leanprover-bot', 'leanprover-community-mathlib4-bot'] bryangingechen
assignee:bryangingechen
2-4431
2 days ago
3-12060
3 days ago
15-9255
15 days
26909 gasparattila
author:gasparattila
feat(LinearAlgebra/Projectivization/Subspace): correspondence between linear and projective subspaces --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-algebra
label:t-algebra$
65/3 Mathlib/LinearAlgebra/Projectivization/Subspace.lean 1 9 ['Vierkantor', 'eric-wieser', 'gasparattila', 'github-actions'] Vierkantor
assignee:Vierkantor
2-4057
2 days ago
2-7027
2 days ago
92-56148
92 days
30280 NotWearingPants
author:NotWearingPants
chore(Algebra/Order/Monoid/Unbundled/MinMax): golf three lemmas using `grind` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-algebra
label:t-algebra$
3/6 Mathlib/Algebra/Order/Monoid/Unbundled/MinMax.lean 1 1 ['euprunin', 'github-actions'] nobody
2-3353
2 days ago
2-76977
2 days ago
2-77010
2 days
29795 Jlh18
author:Jlh18
refactor: weaken HasPullbacks to HasPullback in Over.Pullback Add an abbreviation `HasPullbackAlong f` to mean that all maps into the codomain of `f` have pullbacks along `f`. As discussed in zulip [#mathlib4 > Hom.HasPullback](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Hom.2EHasPullback/with/541055666) The `HasPullbacks` instance on a category `C` for defining the pullback functor along a map `f : X -> Y` between their over categories can be weakened to just a `HasPullbackAlong` condition on `f`. Dually, for `HasPushout` and undercategories. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-category-theory 35/18 Mathlib/CategoryTheory/Comma/Over/Pullback.lean,Mathlib/CategoryTheory/Limits/Shapes/Pullback/HasPullback.lean 2 22 ['Jlh18', 'chrisflav', 'github-actions', 'kckennylau', 'leanprover-bot', 'mathlib4-merge-conflict-bot', 'peabrainiac'] kim-em
assignee:kim-em
2-2992
2 days ago
5-75109
5 days ago
20-15816
20 days
30302 kckennylau
author:kckennylau
feat(AlgebraicGeometry): generalise Proj to graded rings This PR generalises `AlgebraicGeometry.Proj` to take in a graded ring (with an arbitrary `AddSubgroupClass` in a `CommRing`). Currently it takes in a `GradedAlgebra`. Zulip discussion: [#mathlib4 >Proj should take GradedRing](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Proj.20should.20take.20GradedRing/near/543071427) --- Preamble to #26061. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) 125/101 Mathlib/Algebra/DirectSum/Internal.lean,Mathlib/AlgebraicGeometry/ProjectiveSpectrum/Basic.lean,Mathlib/AlgebraicGeometry/ProjectiveSpectrum/Proper.lean,Mathlib/AlgebraicGeometry/ProjectiveSpectrum/Scheme.lean,Mathlib/AlgebraicGeometry/ProjectiveSpectrum/StructureSheaf.lean,Mathlib/AlgebraicGeometry/ProjectiveSpectrum/Topology.lean,Mathlib/RingTheory/GradedAlgebra/FiniteType.lean,Mathlib/RingTheory/GradedAlgebra/HomogeneousLocalization.lean 8 6 ['github-actions', 'kckennylau', 'leanprover-bot'] nobody
1-85619
1 day ago
2-6752
2 days ago
2-6775
2 days
30108 EtienneC30
author:EtienneC30
refactor: generalize LinearMap.toMatrix₂ and Matrix.toLinearMap₂ to sesquilinear forms Generalize [LinearMap.toMatrix₂](https://leanprover-community.github.io/mathlib4_docs/Mathlib/LinearAlgebra/Matrix/SesquilinearForm.html#LinearMap.toMatrix%E2%82%82) to take a sesquilinear map as input. Create `Matrix.toLinearMapₛₗ₂` to generalize [Matrix.toLinearMap₂](https://leanprover-community.github.io/mathlib4_docs/Mathlib/LinearAlgebra/Matrix/SesquilinearForm.html#Matrix.toLinearMap%E2%82%82) to sesquilinear maps, while still keeping [Matrix.toLinearMap₂](https://leanprover-community.github.io/mathlib4_docs/Mathlib/LinearAlgebra/Matrix/SesquilinearForm.html#Matrix.toLinearMap%E2%82%82) to avoid specifying `RingHom.id R` in the bilinear case. Only do so for maps which are semilinear in the first coordinate to avoid specifying `RingHom.id R` for the second homomorphism. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
56/13 Mathlib/LinearAlgebra/Matrix/SesquilinearForm.lean 1 4 ['EtienneC30', 'github-actions', 'themathqueen'] nobody
1-82078
1 day ago
3-4089
3 days ago
8-31268
8 days
30263 NotWearingPants
author:NotWearingPants
feat(Algebra/Order/Ring/Unbundled/Rat): exact form for `|q|` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-algebra
label:t-algebra$
12/1 Mathlib/Algebra/Order/Ring/Unbundled/Rat.lean 1 7 ['NotWearingPants', 'github-actions', 'themathqueen', 'wwylele'] nobody
1-81890
1 day ago
3-59283
3 days ago
3-59317
3 days
30205 NotWearingPants
author:NotWearingPants
feat(Combinatorics/SimpleGraph/Walk): `p.getVert` is `p.support.get` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) maintainer-merge new-contributor t-combinatorics easy 10/0 Mathlib/Combinatorics/SimpleGraph/Walk.lean 1 5 ['NotWearingPants', 'Ruben-VandeVelde', 'github-actions', 'themathqueen'] nobody
1-79227
1 day ago
4-29145
4 days ago
5-294
5 days
30220 NotWearingPants
author:NotWearingPants
chore(Data/List/Nodup): golf `nodup_iff_injective_get` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data new-contributor easy 2/5 Mathlib/Data/List/Nodup.lean 1 4 ['NotWearingPants', 'euprunin', 'github-actions'] nobody
1-78573
1 day ago
4-68618
4 days ago
4-68655
4 days
30275 staroperator
author:staroperator
feat(Order/WellFoundedSet): `partiallyWellOrderedOn_univ_iff` and `Pi.wellQuasiOrderedLE` Connect `Set.PartiallyWellOrderedOn` with `WellQuasiOrdered` and `Set.IsPWO` with `WellQuasiOrderedLE`. Add an instance `Pi.wellQuasiOrderedLE` for Dickson's lemma. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-order 30/0 Mathlib/Order/RelIso/Set.lean,Mathlib/Order/WellFoundedSet.lean,Mathlib/Order/WellQuasiOrder.lean 3 1 ['github-actions'] nobody
1-76098
1 day ago
3-5710
3 days ago
3-5744
3 days
28488 euprunin
author:euprunin
chore(SetTheory): deprecate `mk_multiset_of_countable` and `iSup_succ`. remove `cast_succ`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-set-theory easy 3/13 Mathlib/SetTheory/Cardinal/Basic.lean,Mathlib/SetTheory/Cardinal/Finsupp.lean,Mathlib/SetTheory/Ordinal/Family.lean,Mathlib/SetTheory/Ordinal/NaturalOps.lean 4 13 ['euprunin', 'github-actions', 'mathlib4-merge-conflict-bot', 'vihdzp'] nobody
1-74210
1 day ago
1-74210
1 day ago
16-24548
16 days
30313 chenson2018
author:chenson2018
feat(Data/List/Sigma): grind annotations, some missing API - `grind` annotations for `List.keys`, `List.NodupKeys`, and `List.lookup`, with some shortening of proofs - upstream `keys_append`, `sublist_dlookup`, and `nodupKeys_middle` from https://github.com/leanprover/cslib/pull/68 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data new-contributor 57/62 Mathlib/Data/List/Sigma.lean 1 5 ['chenson2018', 'eric-wieser', 'github-actions'] nobody
1-68030
1 day ago
1-71358
1 day ago
1-71398
1 day
28818 NotWearingPants
author:NotWearingPants
feat(Data/Setoid/Basic): add theorems about lifting a function to its kernel Currently `ker_lift_injective` and `quotientKerEquivOfRightInverse` lift `f` to `ker f` in their definition. This PR makes this function available as `Setoid.ker_lift f` and adds a few more theorems about it. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data new-contributor easy 29/15 Counterexamples/AharoniKorman.lean,Mathlib/Data/Setoid/Basic.lean,Mathlib/NumberTheory/NumberField/CanonicalEmbedding/FundamentalCone.lean,Mathlib/Topology/Separation/Hausdorff.lean 4 18 ['NotWearingPants', 'eric-wieser', 'github-actions', 'kckennylau', 'mathlib4-merge-conflict-bot'] pechersky
assignee:pechersky
1-62506
1 day ago
26-85996
26 days ago
45-14535
45 days
30030 JonBannon
author:JonBannon
feat(MeasureTheory): add `MemLp.Const` class and instances to unify `p = ∞` and `μ.IsFiniteMeasure` cases Although it is possible to ensure that, for example, the `One` instances for `p=∞` and `μ.IsFiniteMeasure` are defeq, introducing an `MemLp.Const` typeclass removes the need to unfold extensively to check this definitional equality, improving performance. cf. https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Lp.20constant.20function.20issue/with/537563137 This PR introduces the requisite class and associated instances. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-measure-probability 85/55 Mathlib/MeasureTheory/Function/ContinuousMapDense.lean,Mathlib/MeasureTheory/Function/L1Space/Integrable.lean,Mathlib/MeasureTheory/Function/LocallyIntegrable.lean,Mathlib/MeasureTheory/Function/LpSeminorm/Basic.lean,Mathlib/MeasureTheory/Function/LpSpace/Basic.lean,Mathlib/MeasureTheory/Function/LpSpace/Indicator.lean 6 13 ['JonBannon', 'github-actions', 'j-loreaux'] urkud
assignee:urkud
1-62502
1 day ago
9-62826
9 days ago
11-69282
11 days
30315 NotWearingPants
author:NotWearingPants
feat(Topology/Connected/LocPathConnected): instance for `LocPathConnected` + `ConnectedSpace` → `PathConnectedSpace` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) awaiting-bench new-contributor t-topology 4/2 Mathlib/Topology/Connected/LocPathConnected.lean 1 7 ['NotWearingPants', 'github-actions', 'j-loreaux', 'leanprover-bot', 'leanprover-community-mathlib4-bot'] nobody
1-50496
1 day ago
1-50496
1 day ago
1-54114
1 day
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 71/0 Mathlib.lean,Mathlib/RingTheory/PowerSeries/Catalan.lean 2 4 ['Ruben-VandeVelde', 'github-actions', 'wwylele'] kbuzzard
assignee:kbuzzard
1-39099
1 day ago
34-35174
1 month ago
34-35204
34 days
28497 euprunin
author:euprunin
chore(RingTheory/LocalRing/ResidueField): deprecate`isLocalHom_residue` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) easy 3/8 Mathlib/RingTheory/LocalRing/ResidueField/Basic.lean,Mathlib/RingTheory/Valuation/ValuationSubring.lean 2 5 ['Ruben-VandeVelde', 'euprunin', 'github-actions', 'mathlib4-merge-conflict-bot'] nobody
1-38374
1 day ago
1-74187
1 day ago
5-6693
5 days
30062 plp127
author:plp127
chore(Order/Defs/PartialOrder): golf non-instance Golf `decidableLTOfDecidableLE` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-order easy 2/6 Mathlib/Order/Defs/PartialOrder.lean 1 1 ['Bergschaf', 'github-actions'] nobody
1-37211
1 day ago
10-70707
10 days ago
10-70696
10 days
28699 chrisflav
author:chrisflav
feat(RingTheory/Cotangent): cotangent of composition with localization away from an element Let `R → S → T` be algebras such that `T` is the localization of `S` away from one element, where `S` is generated over `R` by `P : R[X] → S` with kernel `I` and `Q : S[Y] → T` is the canonical `S`-presentation of `T` with kernel `K`. Denote by `J` the kernel of the composition `R[X,Y] → T`. We deduce `J/J² ≃ₗ[T] T ⊗[S] (I/I²) × K/K²` from the Jacobi Zariski sequence. From Pi1. --- - [x] depends on: #28697 The import increase is expected: This file was PRed in two steps and only the second one depends on more imports. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory large-import 157/4 Mathlib/RingTheory/Extension/Cotangent/LocalizationAway.lean,Mathlib/RingTheory/Extension/Generators.lean,Mathlib/RingTheory/Extension/Presentation/Basic.lean,Mathlib/RingTheory/Smooth/StandardSmoothCotangent.lean 4 5 ['chrisflav', 'erdOne', 'github-actions', 'mathlib4-dependent-issues-bot'] erdOne
assignee:erdOne
1-36440
1 day ago
49-17910
1 month ago
49-19319
49 days
29781 chrisflav
author:chrisflav
feat(RingTheory/Finiteness): a finite and finitely presented algebra is finitely presented We show that if `S` is finite as a module over `R` and finitely presented as an algebra over `R`, then it is finitely presented as a module over `R`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory 136/0 Mathlib.lean,Mathlib/Algebra/Polynomial/AlgebraMap.lean,Mathlib/RingTheory/Finiteness/ModuleFinitePresentation.lean,Mathlib/RingTheory/Ideal/Quotient/Operations.lean,Mathlib/RingTheory/Polynomial/Basic.lean 5 9 ['chrisflav', 'erdOne', 'github-actions'] erdOne
assignee:erdOne
1-35915
1 day ago
21-4745
21 days ago
21-4724
21 days
30000 themathqueen
author:themathqueen
refactor(Analysis/InnerProductSpace/Positive): generalize definition to use `IsSymmetric` instead of `IsSelfAdjoint` and `CompleteSpace` The definition remains the same in complete spaces, but this allows us to use positivity and the partial order without needing completeness. To use the old definition (i.e., `IsSelfAdjoint` and ...), instead of unfolding, use `ContinuousLinearMap.isPositive_def`. `isPositive_iff` is renamed to `isPositive_iff'`, and `isPositive_iff` points to the same thing but with `IsSymmetric` instead of `IsSelfAdjoint`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-analysis 64/54 Mathlib/Analysis/InnerProductSpace/Positive.lean,Mathlib/Analysis/InnerProductSpace/StarOrder.lean 2 3 ['github-actions', 'themathqueen'] j-loreaux
assignee:j-loreaux
1-34930
1 day ago
13-25469
13 days ago
13-31217
13 days
29237 harahu
author:harahu
doc: capitalize archimedean Adjectives derived from the name of a mathematician are ordinarily capitalized in English. The sole exception to this rule that I know of is "abelian". Wikipedia follows this pattern for the [Archimedean property](https://en.wikipedia.org/wiki/Archimedean_property), and when searching Google Scholar for "archimedean" I also mostly get results with a capital A. Consequently, I think it makes sense for mathlib to follow this convention as well. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) 339/338 Counterexamples/MapFloor.lean,Mathlib/Algebra/ContinuedFractions/Computation/ApproximationCorollaries.lean,Mathlib/Algebra/Order/Archimedean/Basic.lean,Mathlib/Algebra/Order/Archimedean/Class.lean,Mathlib/Algebra/Order/Archimedean/Hom.lean,Mathlib/Algebra/Order/Archimedean/Submonoid.lean,Mathlib/Algebra/Order/CompleteField.lean,Mathlib/Algebra/Order/Hom/Basic.lean,Mathlib/Algebra/Order/Module/Archimedean.lean,Mathlib/Algebra/Order/Module/HahnEmbedding.lean,Mathlib/Algebra/Order/Nonneg/Floor.lean,Mathlib/Algebra/Order/Ring/Archimedean.lean,Mathlib/Algebra/Order/Ring/Basic.lean,Mathlib/Algebra/Order/Ring/IsNonarchimedean.lean,Mathlib/Analysis/Calculus/UniformLimitsDeriv.lean,Mathlib/Analysis/Normed/Algebra/Ultra.lean,Mathlib/Analysis/Normed/Field/Ultra.lean,Mathlib/Analysis/Normed/Group/Seminorm.lean,Mathlib/Analysis/Normed/Group/Ultra.lean,Mathlib/Analysis/Normed/Order/Hom/Basic.lean,Mathlib/Analysis/Normed/Order/Hom/Ultra.lean,Mathlib/Analysis/Normed/Ring/Ultra.lean,Mathlib/Analysis/Normed/Unbundled/FiniteExtension.lean,Mathlib/Analysis/Normed/Unbundled/InvariantExtension.lean,Mathlib/Analysis/Normed/Unbundled/SeminormFromBounded.lean,Mathlib/Analysis/Normed/Unbundled/SeminormFromConst.lean,Mathlib/Analysis/Normed/Unbundled/SmoothingSeminorm.lean,Mathlib/Analysis/Normed/Unbundled/SpectralNorm.lean,Mathlib/Analysis/SpecialFunctions/Gamma/Deligne.lean,Mathlib/Data/Fin/SuccPredOrder.lean,Mathlib/Data/Int/SuccPred.lean,Mathlib/Data/NNReal/Defs.lean,Mathlib/Data/Nat/SuccPred.lean,Mathlib/Data/Real/Embedding.lean,Mathlib/GroupTheory/Archimedean.lean,Mathlib/GroupTheory/ArchimedeanDensely.lean,Mathlib/NumberTheory/FunctionField.lean,Mathlib/NumberTheory/LSeries/DirichletContinuation.lean,Mathlib/NumberTheory/LocalField/Basic.lean,Mathlib/NumberTheory/NumberField/FinitePlaces.lean,Mathlib/NumberTheory/Ostrowski.lean,Mathlib/NumberTheory/Padics/Complex.lean,Mathlib/NumberTheory/Padics/MahlerBasis.lean,Mathlib/NumberTheory/Padics/PadicIntegers.lean,Mathlib/NumberTheory/Padics/PadicNorm.lean,Mathlib/NumberTheory/Padics/ValuativeRel.lean,Mathlib/Order/Filter/AtTopBot/Archimedean.lean,Mathlib/Order/Interval/Finset/Box.lean,Mathlib/Order/SuccPred/Archimedean.lean,Mathlib/Order/SuccPred/Basic.lean,Mathlib/Order/SuccPred/IntervalSucc.lean,Mathlib/Order/SuccPred/LinearLocallyFinite.lean,Mathlib/Order/SuccPred/Tree.lean,Mathlib/RingTheory/DedekindDomain/AdicValuation.lean,Mathlib/RingTheory/HahnSeries/Lex.lean,Mathlib/RingTheory/Valuation/Archimedean.lean,Mathlib/RingTheory/Valuation/Basic.lean,Mathlib/RingTheory/Valuation/ValuativeRel/Basic.lean,Mathlib/Topology/Algebra/InfiniteSum/Nonarchimedean.lean,Mathlib/Topology/Algebra/Nonarchimedean/AdicTopology.lean,Mathlib/Topology/Algebra/Nonarchimedean/Bases.lean,Mathlib/Topology/Algebra/Nonarchimedean/Basic.lean,Mathlib/Topology/Algebra/Nonarchimedean/Completion.lean,Mathlib/Topology/Algebra/Nonarchimedean/TotallyDisconnected.lean,Mathlib/Topology/Algebra/OpenSubgroup.lean,Mathlib/Topology/Algebra/Order/Archimedean.lean,Mathlib/Topology/Algebra/Valued/LocallyCompact.lean,Mathlib/Topology/Algebra/Valued/NormedValued.lean,Mathlib/Topology/Connected/Basic.lean,Mathlib/Topology/MetricSpace/BundledFun.lean,Mathlib/Topology/MetricSpace/Ultra/Basic.lean,Mathlib/Topology/MetricSpace/Ultra/Pi.lean,Mathlib/Topology/MetricSpace/Ultra/TotallySeparated.lean,Mathlib/Topology/UniformSpace/Ultra/Basic.lean,Mathlib/Topology/UniformSpace/Ultra/Completion.lean,Mathlib/Topology/UniformSpace/Ultra/Constructions.lean 76 5 ['euprunin', 'github-actions', 'mathlib4-merge-conflict-bot'] dwrensha
assignee:dwrensha
1-32275
1 day ago
24-30832
24 days ago
35-31976
35 days
28546 Sfgangloff
author:Sfgangloff
feat(SymbolicDynamics): basic setup of Zd, full shift, cylinders, pat… # Symbolic dynamics on groups: core API and entropy along finite shapes This PR adds a **group-generic** foundation for symbolic dynamics over an arbitrary group `G`, together with convenient specializations for `ℤ` and `ℤ^d`. ## Summary of additions - **Full shift and shift action** - `abbrev FullShift (A G) := G → A` (inherits product topology from the Π-type). - Right shift `shift g x` with convention `(shift g x) h = x (h * g)`. - **Cylinders and topology** - `cylinder U x : Set (G → A)` for finite `U : Finset G`. - Cylinders are open under `[DiscreteTopology A]`; with a finite alphabet they are also closed. - Equality with dependent products: `cylinder U x = Set.pi (↑U) (fun i => ({x i} : Set A))`, enabling use of the `Set.pi` API. - **Patterns, occurrences, and subshifts** - `Pattern A G` with finite `support : Finset G` and `data : support → A`. - `Pattern.occursIn p x g` (occurrence at translate `g`) and the expected shift law. - `forbids F` and `Subshift A G` (closed, shift-invariant subsets). - `FixedSupport A G U` with an equivalence to `(U → A)` to obtain finiteness. - **Language on finite shapes and counting** - `languageOn X U`, `languageCardOn X U`, and `patternCountOn Y U`. - **Entropy along a shape sequence** - `limsupAtTop` (as an `sInf` of eventual upper bounds). - `entropyAlong X F hF := limsup (log (patternCountOn X (F n) + 1) / |F n|)` for any nonempty finite shapes `F : ℕ → Finset G` (the `+ 1` avoids `log 0`). - **Specializations** - `IntShapes`: segments `[-n,n]` on `Multiplicative ℤ`, with `entropy_Z`. - `ZdShapes`: boxes `[-n,n]^d` on `ℤ^d` (as functions `Fin d → ℤ`), with `entropy_Zd`. ## Mathematical remarks - The API is **shape-parametric**: entropy is defined along user-provided finite shapes. - On **amenable** groups, using a **Følner** sequence yields a canonical value (Ornstein–Weiss). This PR does not assume amenability; the family of shapes is an explicit input. ## Motivation Provide a clean, reusable base for symbolic dynamics on groups in mathlib. ## Future work - Add a Følner predicate and prove shape-independence / limit existence on amenable groups. - Expand the `ℤ`/`ℤ^d` toolkit (alternative shapes, mixing, factors). - Develop 1D theory and, longer-term, multidimensional SFT results (e.g. along the lines of Hochman–Meyerovitch). new-contributor t-dynamics 747/0 Mathlib.lean,Mathlib/Dynamics/SymbolicDynamics/Basic.lean 2 80 ['Sfgangloff', 'eric-wieser', 'github-actions', 'kckennylau', 'sgouezel'] sgouezel
assignee:sgouezel
1-31597
1 day ago
1-31598
1 day ago
38-50465
38 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 20/7 Mathlib/Topology/Sequences.lean,docs/overview.yaml,docs/undergrad.yaml 3 1 ['github-actions'] nobody
1-30543
1 day ago
1-30543
1 day ago
1-31019
1 day
28097 themathqueen
author:themathqueen
feat(LinearAlgebra/Matrix/PosDef): kronecker of positive (semi-)definite matrices is positive (semi-)definite This first shows that `U * x * star U` is positive (semi-)definite if and only if `x` is, for an invertible matrix `U` in a not necessarily commutative star-ring. Then using the spectral theorem, it follows that the kronecker of positive (semi-)definite matrices is positive (semi-)definite. --- - [x] depends on: #28093 - [x] depends on: #28476 - [x] depends on: #28544 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
88/5 Mathlib/Algebra/Star/SelfAdjoint.lean,Mathlib/LinearAlgebra/Matrix/Hermitian.lean,Mathlib/LinearAlgebra/Matrix/Kronecker.lean,Mathlib/LinearAlgebra/Matrix/PosDef.lean 4 10 ['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'themathqueen'] joneugster
assignee:joneugster
1-29639
1 day ago
1-29780
1 day ago
37-53127
37 days
29861 themathqueen
author:themathqueen
feat(LinearAlgebra/Matrix/PosDef): `vecMulVec a (star a)` is positive semi-definite The matrices `vecMulVec a (star a)` and `vecMulVec (star a) a` are always positive semi-definite. And in a nontrivial commutative ring with nontrivial index, they are never positive definite. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
64/0 Mathlib/Data/Matrix/Mul.lean,Mathlib/LinearAlgebra/Matrix/PosDef.lean 2 7 ['eric-wieser', 'github-actions', 'themathqueen'] ocfnash
assignee:ocfnash
1-29257
1 day ago
17-20190
17 days ago
18-8027
18 days
30322 kckennylau
author:kckennylau
feat(RingTheory): base change of graded algebra In this file we show that if `𝒜` is a graded `R`-algebra, and `S` is any `R`-algebra, then `S ⊗[R] 𝒜` (which is actually `fun i ↦ (𝒜 i).baseChange S`) is a graded `S`-algebra with the same grading. --- Split from #26061. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) 269/48 Mathlib.lean,Mathlib/Algebra/DirectSum/Basic.lean,Mathlib/Algebra/DirectSum/Decomposition.lean,Mathlib/Algebra/DirectSum/Module.lean,Mathlib/Algebra/Order/Module/HahnEmbedding.lean,Mathlib/LinearAlgebra/DirectSum/Finsupp.lean,Mathlib/LinearAlgebra/DirectSum/TensorProduct.lean,Mathlib/LinearAlgebra/TensorProduct/Decomposition.lean,Mathlib/LinearAlgebra/TensorProduct/Tower.lean,Mathlib/RingTheory/Flat/Basic.lean,Mathlib/RingTheory/Flat/FaithfullyFlat/Basic.lean,Mathlib/RingTheory/GradedAlgebra/TensorProduct.lean 12 1 ['github-actions'] nobody
1-22914
1 day ago
1-27782
1 day ago
1-27759
1 day
29257 harahu
author:harahu
doc: attach "pre", "pseudo", "semi" and "sub" as a prefixes where they are now free-standing These are all examples of [bound morphemes](https://en.wikipedia.org/wiki/Bound_and_free_morphemes) and should be attached, either in closed form or by hyphen, to some other construct. Whether to write the resulting words in closed form or with a hyphen is a stylistic choice and I am open to discussing the specifics, should that be of interest. I've made choices based on existing literature and what I personally found natural, but other opinions are welcome. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-meta 50/50 Mathlib/Algebra/Star/NonUnitalSubsemiring.lean,Mathlib/Analysis/Matrix.lean,Mathlib/Analysis/Normed/Field/WithAbs.lean,Mathlib/Analysis/Normed/Group/BallSphere.lean,Mathlib/Analysis/Normed/Module/Basic.lean,Mathlib/Lean/Meta/KAbstractPositions.lean,Mathlib/Lean/Meta/RefinedDiscrTree/Initialize.lean,Mathlib/MeasureTheory/Measure/Regular.lean,Mathlib/Probability/Martingale/BorelCantelli.lean,Mathlib/Topology/EMetricSpace/Basic.lean,Mathlib/Topology/EMetricSpace/Defs.lean,Mathlib/Topology/MetricSpace/Bounded.lean,Mathlib/Topology/MetricSpace/Gluing.lean,Mathlib/Topology/MetricSpace/IsometricSMul.lean,Mathlib/Topology/MetricSpace/ProperSpace.lean,Mathlib/Topology/MetricSpace/Pseudo/Defs.lean,Mathlib/Topology/MetricSpace/ThickenedIndicator.lean,Mathlib/Topology/MetricSpace/Thickening.lean,Mathlib/Topology/Metrizable/Basic.lean,Mathlib/Topology/Metrizable/Uniformity.lean,scripts/autolabel.lean 21 5 ['euprunin', 'github-actions', 'harahu', 'mathlib4-merge-conflict-bot'] JovanGerb
assignee:JovanGerb
1-17272
1 day ago
1-37497
1 day ago
36-30712
36 days
30332 euprunin
author:euprunin
feat: unregister `bound` for `hint` This helps mitigate the effects of issue #29831 and makes `hint` more useful. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-meta 0/6 Mathlib/Tactic/Bound.lean 1 1 ['github-actions'] nobody
1-15589
1 day ago
1-15598
1 day ago
1-15637
1 day
30050 themathqueen
author:themathqueen
chore(Analysis/Matrix/Order): `IsStrictlyPositive x` iff `x.PosDef` --- - [x] depends on: #29896 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
27/13 Mathlib/Analysis/Matrix/Order.lean,Mathlib/Analysis/SpecialFunctions/ContinuousFunctionalCalculus/Rpow/Basic.lean 2 2 ['github-actions', 'mathlib4-dependent-issues-bot'] nobody
1-14945
1 day ago
1-55175
1 day ago
1-55164
1 day
30287 mitchell-horner
author:mitchell-horner
feat(Combinatorics/SimpleGraph): define `IsCompleteBetween` `IsCompleteBetween` is the condition that two subsets of vertices are completely connected in a simple graph. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-combinatorics 20/0 Mathlib/Combinatorics/SimpleGraph/Basic.lean 1 2 ['YaelDillies', 'github-actions', 'vlad902'] nobody
1-13056
1 day ago
2-68094
2 days ago
2-68095
2 days
30269 joelriou
author:joelriou
refactor(CategoryTheory/Generator): use ObjectProperty instead ot Set In certain applications (see #30247), it becomes unpractical to have certains notions like `IsSeparating` defined for `Set C`, while the API for the relatively new `ObjectProperty` is expanding. In this PR, we move the definition of `IsSeparating` to the `ObjectProperty` namespace. --- - [x] depends on: #30294 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-category-theory 448/305 Mathlib/Algebra/Category/ModuleCat/AB.lean,Mathlib/Algebra/Category/ModuleCat/Presheaf/Generator.lean,Mathlib/CategoryTheory/Abelian/GrothendieckCategory/EnoughInjectives.lean,Mathlib/CategoryTheory/Abelian/GrothendieckCategory/ModuleEmbedding/GabrielPopescu.lean,Mathlib/CategoryTheory/Adjunction/AdjointFunctorTheorems.lean,Mathlib/CategoryTheory/Comma/StructuredArrow/Small.lean,Mathlib/CategoryTheory/Generator/Basic.lean,Mathlib/CategoryTheory/Generator/HomologicalComplex.lean,Mathlib/CategoryTheory/Generator/Indization.lean,Mathlib/CategoryTheory/Generator/Preadditive.lean,Mathlib/CategoryTheory/Generator/Presheaf.lean,Mathlib/CategoryTheory/Generator/Sheaf.lean 12 2 ['github-actions', 'mathlib4-dependent-issues-bot'] nobody
1-8516
1 day ago
1-8516
1 day ago
1-8494
1 day
30336 kckennylau
author:kckennylau
feat(RingTheory): some lemmas about the irrelevant ideal This PR adds some lemmas about the irrelevant ideal of a graded ring, such as the fact that it is the iSup of each positively graded component. --- Split from #26061. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory 37/5 Mathlib/RingTheory/GradedAlgebra/Homogeneous/Ideal.lean 1 1 ['github-actions'] nobody
1-8378
1 day ago
1-8382
1 day ago
1-8419
1 day
30335 joelriou
author:joelriou
feat(CategoryTheory/Adjunction): more mate compatibilities We obtain various lemmas about adjunctions between functors by computing `conjugateEquiv` in case of associators, unitors, and whiskerings. We deduce a way to obtain compatibilites with respect to composition of functors of left adjoints assuming that we have these compatibilites for right adjoints. In #30318, this shall be applied to the study of the compatibilities with respect to composition of the pullback functors for presheaves of modules. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-category-theory 214/4 Mathlib.lean,Mathlib/CategoryTheory/Adjunction/Basic.lean,Mathlib/CategoryTheory/Adjunction/CompositionIso.lean,Mathlib/CategoryTheory/Adjunction/Mates.lean 4 5 ['github-actions', 'joelriou'] nobody
1-7717
1 day ago
1-9706
1 day ago
1-9684
1 day
30286 erdOne
author:erdOne
feat(AlgebraicGeometry): quasi-affine if covered by affine basic opens of global sections --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebraic-geometry 120/69 Mathlib/AlgebraicGeometry/AffineScheme.lean,Mathlib/AlgebraicGeometry/IdealSheaf/Basic.lean,Mathlib/AlgebraicGeometry/Morphisms/Affine.lean,Mathlib/AlgebraicGeometry/Morphisms/Basic.lean,Mathlib/AlgebraicGeometry/Morphisms/Immersion.lean,Mathlib/AlgebraicGeometry/Morphisms/QuasiCompact.lean,Mathlib/AlgebraicGeometry/OpenImmersion.lean,Mathlib/AlgebraicGeometry/QuasiAffine.lean,Mathlib/Topology/Constructible.lean 9 12 ['chrisflav', 'erdOne', 'github-actions', 'joelriou', 'mathlib4-merge-conflict-bot'] nobody
1-2849
1 day ago
1-3600
1 day ago
1-80763
1 day
30337 kckennylau
author:kckennylau
chore: delete wrong docstring for irrelevant ideal The expression given `{a | ∀ (i : ι), i ≤ 0 → aᵢ = 0}` does not define an ideal, because it is not closed under (external) multiplication. For example, if x has grade 1 and y has grade -2, then x will be in this "ideal", but xy will not. Zulip discussion: [#mathlib4 > irrelevant ideal cannot be generalised](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/irrelevant.20ideal.20cannot.20be.20generalised/near/543800961) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory 0/5 Mathlib/RingTheory/GradedAlgebra/Homogeneous/Ideal.lean 1 1 ['github-actions'] nobody
1-2758
1 day ago
1-2783
1 day ago
1-2820
1 day
29903 joelriou
author:joelriou
chore(CategoryTheory): split Limits.Presentation The part of the code involving "set theory" (via finitely presentable objects) is moved to `CategoryTheory.Presentable.Presentation`. As `ColimitPresentation` is going to be used more widely, this will reduce dependencies to set theory for some files. - [x] depends on: #29851 - [x] depends on: #29849 - [x] depends on: #29843 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-category-theory 154/133 Mathlib.lean,Mathlib/CategoryTheory/Limits/Presentation.lean,Mathlib/CategoryTheory/ObjectProperty/Ind.lean,Mathlib/CategoryTheory/Presentable/ColimitPresentation.lean 4 3 ['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] nobody
1-1808
1 day ago
4-8341
4 days ago
4-8320
4 days
30338 grunweg
author:grunweg
feat: local frames in a vector bundle We define a predicate `IsLocalFrameOn`, for a collection of sections of a vector bundle to be a local frame. We provide some basic API, such as the coefficients of a section `t` w.r.t. a local frame, or proving smoothness of `t` via proving the smoothness of its local frame coefficients. A future PR will construct actual local frames, and use these to define the local extension of a tangent vector to a vector field near a point. From the path towards geodesics and the Levi-Civita connection. Co-authored-by: Patrick Massot [patrickmassot@free.fr](mailto:patrickmassot@free.fr) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-differential-geometry 282/0 Mathlib.lean,Mathlib/Geometry/Manifold/VectorBundle/LocalFrame.lean 2 1 ['github-actions'] nobody
1-1086
1 day ago
1-1895
1 day ago
1-1933
1 day
30326 kebekus
author:kebekus
feat: commutativity of `mul` and `finprod` For (semi-)rings without zero divisors, show that multiplication commutes with `finprod`. Following a [brief discussion of Zulip](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Naming.20inconstency.2C.20finsum.20and.20multiplication/with/543461589), unify naming between theorems about multiplication and theorems about scalar multiplication. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
74/4 Mathlib/Algebra/BigOperators/Finprod.lean 1 3 ['Vierkantor', 'github-actions', 'kebekus'] nobody
1-885
1 day ago
1-20980
1 day ago
1-21018
1 day
25971 joelriou
author:joelriou
feat(CategoryTheory): pseudofunctors to Cat This PR adds convenience lemmas for pseudofunctors to `Cat`, mostly using the `to_app` attribute. The simp set for the `to_app` attribute is extended in order to take into account that in `Cat`, associators and unitors induce identities. --- - [x] depends on: #30134 This PR continues the work from #24384. Original PR: https://github.com/leanprover-community/mathlib4/pull/24384 t-category-theory 175/24 Mathlib.lean,Mathlib/CategoryTheory/Bicategory/Functor/Cat.lean,Mathlib/CategoryTheory/Bicategory/Grothendieck.lean,Mathlib/CategoryTheory/Bicategory/Strict/Pseudofunctor.lean,Mathlib/Tactic/CategoryTheory/ToApp.lean,MathlibTest/CategoryTheory/ToApp.lean 6 20 ['callesonne', 'chrisflav', 'github-actions', 'joelriou', 'mathlib4-dependent-issues-bot', 'yuma-mizuno'] robin-carlier
assignee:robin-carlier
1-77
1 day ago
1-113
1 day ago
3-19843
3 days
30179 EtienneC30
author:EtienneC30
feat: uncurrying the product measure gives the product measure --- - [x] depends on: #30161 - [x] depends on: #30178 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-measure-probability 51/0 Mathlib/Probability/ProductMeasure.lean 1 2 ['github-actions', 'mathlib4-dependent-issues-bot'] nobody
0-85302
23 hours ago
0-85305
23 hours ago
0-85287
23 hours
29649 MichaelStollBayreuth
author:MichaelStollBayreuth
feat(Analysis/Normed/Algebra/GelfandMazur): new file This adds two version of the *Gelfand-Mazur* *Theorem*: ```lean NormedAlgebra.Complex.nonempty_algEquiv (F : Type*) [NormedRing F] [NormOneClass F] [NormMulClass F] [NormedAlgebra ℂ F] [Nontrivial F] : Nonempty (ℂ ≃ₐ[ℂ] F) NormedAlgebra.Real.nonempty_algEquiv_or (F : Type*) [NormedField F] [NormedAlgebra ℝ F] : Nonempty (F ≃ₐ[ℝ] ℝ) ∨ Nonempty (F ≃ₐ[ℝ] ℂ) ``` The version for complex algebras differs in its assumptions from the existing version [NormedRing.algEquivComplexOfComplete](https://leanprover-community.github.io/mathlib4_docs/Mathlib/Analysis/Normed/Algebra/Spectrum.html#NormedRing.algEquivComplexOfComplete) (nontrivial normed algebra with multiplicative norm vs. complete division ring with submultiplicative norm). A version for real algebras is not yet in Mathlib; it is needed in the context of implementing (absolute) heights; see [Heights](https://github.com/MichaelStollBayreuth/Heights). --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-analysis 367/0 Mathlib.lean,Mathlib/Analysis/Normed/Algebra/GelfandMazur.lean 2 7 ['MichaelStollBayreuth', 'github-actions', 'grunweg', 'j-loreaux', 'mathlib4-merge-conflict-bot'] j-loreaux
assignee:j-loreaux
0-84374
23 hours ago
13-10269
13 days ago
24-79890
24 days
29430 RemyDegenne
author:RemyDegenne
refactor(Probability): change stopping times to take values in `WithTop` This PR changes stopping times to have type `Ω → WithTop ι` instead of `Ω → ι`. Previously, a stopping time for a filtration indexed by Nat had to have value in Nat. That's not representative of the way stopping times are used in probability. A typical stopping time is the first time at which we see a head in an infinite sequence of coin flips. That time could be infinite (although it is almost surely finite). We can't represent it with a `Ω → Nat` stopping time: if we choose an arbitrary value in Nat for the event that it is infinite, we destroy the stopping time property. We faced that issue in the `BorelCantelli` file, in which we avoided such a possibly infinite stopping time by introducing a sequence of bounded stopping times. We had to prove additional lemmas about them since we could not directly use the API for stopped processes. With the new type, that file is greatly simplified as the API is directly usable, and we can write the proof as we would on paper. The issue with the previous stopping time implementation was noted in [Ying and Degenne, A Formalization of Doob’s Martingale Convergence Theorems in mathlib, CPP 2023, https://dl.acm.org/doi/pdf/10.1145/3573105.3575675]. Other changes: - the sigma-algebra generated by a stopping time is now a sub-sigma algebra by definition - `measurableSet_eq_stopping_time` is generalized and the now useless `measurableSet_eq_stopping_time_of_countable` is removed - `hitting` is renamed to `hittingBtwn` - a new `hittingAfter` is introduced and used in the Borel-Cantelli proof. That proof is now much simpler since we can use a stopped process as intended instead of going around the limitations of the previous stopping time implementation. --- - [ ] depends on: #29466 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-measure-probability 1124/555 Mathlib.lean,Mathlib/MeasureTheory/Constructions/BorelSpace/WithTop.lean,Mathlib/Probability/Martingale/Basic.lean,Mathlib/Probability/Martingale/BorelCantelli.lean,Mathlib/Probability/Martingale/OptionalSampling.lean,Mathlib/Probability/Martingale/OptionalStopping.lean,Mathlib/Probability/Martingale/Upcrossing.lean,Mathlib/Probability/Process/HittingTime.lean,Mathlib/Probability/Process/Stopping.lean,Mathlib/Topology/Order/WithTop.lean 10 11 ['RemyDegenne', 'github-actions', 'kex-y', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] nobody
0-84256
23 hours ago
0-84256
23 hours ago
0-84233
23 hours
30341 bwangpj
author:bwangpj
feat: Limits for ProfiniteAddGrp `to_additive` was not working in the construction of limits in the category of profinite groups; I believe the fix was to add `@[to_additive self]` to the `Profinite` declaration. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-topology 12/8 Mathlib/Topology/Algebra/Category/ProfiniteGrp/Basic.lean,Mathlib/Topology/Category/Profinite/Basic.lean 2 1 ['github-actions'] nobody
0-82998
23 hours ago
0-82998
23 hours ago
0-83079
23 hours
27273 xroblot
author:xroblot
feat(IntermediateField/LinearDisjoint): Two fields are linearly disjoint iff they are disjoint in the Galois case --- - [x] depends on: #26841 t-algebra
label:t-algebra$
73/1 Mathlib/FieldTheory/Galois/Basic.lean,Mathlib/FieldTheory/IntermediateField/Basic.lean,Mathlib/FieldTheory/LinearDisjoint.lean 3 6 ['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'tb65536'] mattrobball
assignee:mattrobball
0-81266
22 hours ago
13-30811
13 days ago
13-32422
13 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/) 208/0 Mathlib.lean,Mathlib/RingTheory/Polynomial/Resultant/Quadratic.lean 2 2 ['github-actions', 'mathlib4-dependent-issues-bot'] nobody
0-80716
22 hours ago
0-82174
22 hours ago
0-86058
23 hours
29921 mans0954
author:mans0954
refactor(RingTheory/Polynomial/SmallDegreeVieta) : Convert to {p : R[X]} (hp : p.natDegree = 2) Convert `RingTheory/Polynomial/SmallDegreeVieta` from `{a b c : R} (C a * X ^ 2 + C b * X + C c)` to `{p : R[X]} (hp : p.natDegree = 2)` (see [Zulip discussion](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/discriminants.20of.20low.20degree.20polynomials/with/538010519)) --- - [x] depends on: #29981 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory 75/60 Mathlib/RingTheory/Polynomial/SmallDegreeVieta.lean 1 6 ['JovanGerb', 'github-actions', 'kckennylau', 'mans0954', 'mathlib4-dependent-issues-bot', 'vihdzp'] nobody
0-79808
22 hours ago
0-82165
22 hours ago
2-2774
2 days
30316 NotWearingPants
author:NotWearingPants
feat(Topology/Connected): locally (path-)connected compact spaces have finitely many (path-)connected components feat(Topology/Connected): locally (path-)connected compact spaces have finitely many (path-)connected components Locally (path-)connectedness implies all (path-)connected components are open, so they form an open cover. Compactness implies there's a finite subcover. Since the components are disjoint, the subcover must equal the cover. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) large-import new-contributor t-topology 41/0 Mathlib/Topology/Connected/Clopen.lean,Mathlib/Topology/Connected/LocPathConnected.lean,Mathlib/Topology/Connected/LocallyConnected.lean,Mathlib/Topology/Connected/PathConnected.lean 4 4 ['NotWearingPants', 'github-actions', 'j-loreaux'] nobody
0-76249
21 hours ago
0-76275
21 hours ago
1-703
1 day
30317 NotWearingPants
author:NotWearingPants
feat(Combinatorics/SimpleGraph/Acyclic): homomorphisms into an acyclic graph implies acyclic --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-combinatorics 43/4 Mathlib/Combinatorics/SimpleGraph/Acyclic.lean 1 3 ['NotWearingPants', 'github-actions', 'vlad902'] nobody
0-75817
21 hours ago
1-53771
1 day ago
1-53804
1 day
28819 ScottCarnahan
author:ScottCarnahan
feat (Data/Finsupp): define convolution smul for finsupps on formal functions This is a generalization of the multiplication action of the ring of Laurent polynomials on the space of formal power series with unbounded pole terms. --- - [ ] depends on: #28876 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) 86/0 Mathlib.lean,Mathlib/Data/Finsupp/PointwiseSMul.lean 2 3 ['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] nobody
0-72301
20 hours ago
0-72325
20 hours ago
1-80577
1 day
30321 chrisflav
author:chrisflav
feat(CategoryTheory/Sites): small `0`-hypercovers A `w`-`0`-hypercover `E` is `w'`-small if there exists an indexing type `ι` in `Type w'` and a restriction map `ι → E.I₀` such that the restriction of `E` to `ι` is still covering. This is weaker than `E.I₀` being `w'`-small. For example, every Zariski cover of `X : Scheme.{u}` is `u`-small, because `X` itself suffices as indexing type. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-category-theory 116/7 Mathlib/AlgebraicGeometry/Cover/MorphismProperty.lean,Mathlib/CategoryTheory/MorphismProperty/Local.lean,Mathlib/CategoryTheory/Sites/Hypercover/Zero.lean,Mathlib/CategoryTheory/Sites/MorphismProperty.lean 4 5 ['chrisflav', 'github-actions', 'joelriou'] nobody
0-71541
19 hours ago
0-71541
19 hours ago
1-10041
1 day
30344 Deep0Thinking
author:Deep0Thinking
feat(MeasureTheory/IntervalIntegral): 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 226/0 Mathlib.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral/MeanValue.lean 2 4 ['github-actions', 'plp127'] nobody
0-66596
18 hours ago
0-79855
22 hours ago
0-79888
22 hours
30354 NotWearingPants
author:NotWearingPants
feat(Combinatorics/SimpleGraph/Connectivity/WalkCounting): a spanning subgraph has the same or more connected components --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-combinatorics 8/0 Mathlib/Combinatorics/SimpleGraph/Connectivity/Connected.lean,Mathlib/Combinatorics/SimpleGraph/Connectivity/WalkCounting.lean 2 1 ['github-actions'] nobody
0-65512
18 hours ago
0-65525
18 hours ago
0-65559
18 hours
27673 b-reinke
author:b-reinke
feat(GroupTheory/FreeGroup): add cyclic reduction of words This PR adds the definition of `reduceCyclically`. This function produces a subword of a word `w` by cancelling the first and last letters of `w` as long as possible. If `w` is reduced, the resulting word will be cyclically reduced. It is a part of a series of PR on the theory of cyclically reduced words. Upstreamed from the [EquationalTheories](https://github.com/teorth/equational_theories) project. - [x] depends on: #25966 - [x] depends on: #27672 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-group-theory 76/0 Mathlib/GroupTheory/FreeGroup/CyclicallyReduced.lean 1 6 ['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'vlad902'] tb65536
assignee:tb65536
0-62502
17 hours ago
8-39164
8 days ago
8-40476
8 days
27971 smmercuri
author:smmercuri
feat: weak approximation theorems for infinite places of a number field Under the diagonal embedding into infinite places, a number field $K$ is dense inside both the product $\prod_{v \mid \infty} (K, v)$, where $(K, v)$ denotes $K$ equipped with $v$'s topology, and the infinite adele ring $\prod_v K_v$. This PR continues the work from #22153. Original PR: https://github.com/leanprover-community/mathlib4/pull/22153 --- - [x] depends on: #27969 large-import FLT t-algebra t-number-theory
label:t-algebra$
98/2 Mathlib/Analysis/Normed/Field/WithAbs.lean,Mathlib/NumberTheory/NumberField/AdeleRing.lean,Mathlib/NumberTheory/NumberField/InfinitePlace/Basic.lean 3 4 ['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'smmercuri'] Vierkantor
assignee:Vierkantor
0-62501
17 hours ago
8-17188
8 days ago
8-19838
8 days
29960 yonggyuchoimath
author:yonggyuchoimath
feat(Algebra/Category/Ring): equalizers of pushout maps of tensor product inclusions This PR defines a ring map `S →ₗ[R] S ⊗[R] S : s ↦ (s ⊗ₜ[R] 1) - (1 ⊗ₜ[R] s)` for an `R`-algebra `S`, and show that its kernel is exactly (the image of) `R` if `S` is faithfully flat over `R`. Changes: * `TensorProduct.AlgebraTensorModule.distribBaseChange`: Origianlly takes `M` and `N`, where `M` is an `R`-module with an additional instance `IsScalarTower R A M`. This is unnecessary, so I changed the `M` and `N` into `N` and `Q`, now both of which are merely modules over `R`. Main results : * Add compatibility of `Algebra.TensorProduct.includeLeft` (or `Algebra.TensorProduct.includeRight`) with `TensorProduct.AlgebraTensorModule.distribBaseChange` and `LinearMap.lTensor` * Define `Algebra.TensorProduct.includeLeftSubRight`, which is the `R`-linear map `S →ₗ[R] S ⊗[R] S` sending `s : S` to `(s ⊗ₜ[R] 1) - (1 ⊗ₜ[R] s)`. * `Algebra.TensorProduct.exactIncludeLeftSubRight_of_faithfullyFlat`: the pair `algebraMap : R → S` and `includeLeftSubRight R S : S → S ⊗[R] S` is exact if `S` is a faithfully flat `R`-algebra. new-contributor 229/1 Mathlib.lean,Mathlib/LinearAlgebra/TensorProduct/Tower.lean,Mathlib/RingTheory/TensorProduct/Basic.lean,Mathlib/RingTheory/TensorProduct/IncludeLeftSubRight.lean 4 3 ['erdOne', 'github-actions', 'yonggyuchoimath'] TwoFX
assignee:TwoFX
0-62498
17 hours ago
8-82782
8 days ago
11-30852
11 days
29996 vihdzp
author:vihdzp
chore(Order/Concept): `IsIntent` and `IsExtent` We define predicates for a set to be an intent/extent, and use them to define alternate constructors for a concept. Using these, we golf the complete lattice instances. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-order 161/95 Mathlib/Order/Concept.lean 1 17 ['github-actions', 'linesthatinterlace', 'plp127', 'vihdzp'] Vierkantor
assignee:Vierkantor
0-62497
17 hours ago
13-36606
13 days ago
13-36640
13 days
30071 Jlh18
author:Jlh18
feat: dualize Pseudofunctor.CoGrothendieck results to Pseudofunctor.Grothendieck Continuing from #29681, dualize all definitions and lemmas in the namespace `Pseudofunctor.CoGrothendieck` to results in the namespace `Pseudofunctor.Grothendieck`. - [ ] depends on: #29681 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-category-theory 121/9 Mathlib/CategoryTheory/Bicategory/Grothendieck.lean 1 3 ['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] riccardobrasca
assignee:riccardobrasca
0-62495
17 hours ago
7-81638
7 days ago
8-5744
8 days
30088 FernandoChu
author:FernandoChu
feat(CategoryTheory): `Exists` gives images We show that (the underlying arrow of) `(exists f.obj) x` is an image. This is a prerequisite of the [MTT project](https://github.com/kyoDralliam/model-theory-topos), which aims to use the internal language of toposes to reason about e.g. sheaves. t-category-theory 147/2 Mathlib/CategoryTheory/Limits/Shapes/Images.lean,Mathlib/CategoryTheory/Skeletal.lean,Mathlib/CategoryTheory/Subobject/Basic.lean 3 6 ['FernandoChu', 'github-actions', 'joelriou'] robin-carlier
assignee:robin-carlier
0-62494
17 hours ago
8-33119
8 days ago
8-48111
8 days
30107 grunweg
author:grunweg
chore: track occurrences of 'nonrec' as technical debt Matches leanprover-community/leanprover-community.github.io#689: only merge when that is deemed a good idea. -------- TODO: make the count more robust, for instance count all occurrences of "^nonrec " plus those of "^[private|protected] nonrec ". --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) tech debt CI 1/0 scripts/technical-debt-metrics.sh 1 1 ['github-actions'] robertylewis
assignee:robertylewis
0-62493
17 hours ago
8-35381
8 days ago
8-35360
8 days
30116 FormulaRabbit81
author:FormulaRabbit81
feat(Measure): proof that a relatively compact set of measures is tight --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) large-import t-measure-probability 196/2 Mathlib/MeasureTheory/Measure/Tight.lean 1 1 ['github-actions'] kex-y
assignee:kex-y
0-62493
17 hours ago
7-72749
7 days ago
7-72783
7 days
30231 NotWearingPants
author:NotWearingPants
feat(LinearAlgebra/Matrix/Charpoly): `trace_eq_neg_charpoly_coeff` using `nextCoeff` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-algebra easy
label:t-algebra$
6/3 Mathlib/LinearAlgebra/Matrix/Charpoly/Coeff.lean,Mathlib/LinearAlgebra/Matrix/Charpoly/Eigs.lean 2 3 ['NotWearingPants', 'github-actions', 'mathlib4-merge-conflict-bot'] nobody
0-60031
16 hours ago
0-60053
16 hours ago
4-40890
4 days
28793 grunweg
author:grunweg
feat: smooth immersions Define smooth immersions between manifolds. We use a definition which allows for corners, infinite dimension and arbitrary fields. Future PRs will - prove that immersions are C^n (#28796), - prove another characterisation of immersions: f is immersed at x iff the differential df_x splits, i.e. is injective, has closed range and its image has a closed complement, and in particular that a map between finite-dimensional manifolds over a complete field is an immersion iff its differential is injective, - use this to prove that the product (#28853) and composition of immersions is an immersion, - use this theory to give more conceptual proofs of half of `Manifold/Instances/Icc.lean` (#29077) - define smooth embeddings and immersed and embedded smooth submanifolds --- - [x] depends on: #28701 Most of the above has been done at https://github.com/grunweg/mathlib4/tree/MR-define-immersions. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-differential-geometry 487/0 Mathlib.lean,Mathlib/Geometry/Manifold/IsImmersionEmbedding.lean,Mathlib/Geometry/Manifold/LocalSourceTargetProperty.lean,docs/references.bib 4 98 ['chrisflav', 'github-actions', 'grunweg', 'mathlib4-dependent-issues-bot', 'sgouezel'] sgouezel
assignee:sgouezel
0-54784
15 hours ago
0-54795
15 hours ago
11-78779
11 days
30311 j-loreaux
author:j-loreaux
feat: the unitary group in a C⋆-algebra is locally path connected When `A` is a unital C⋆-algebra and `u : unitary A` is a unitary element whose distance to `1` is less that `2`, the spectrum of `u` is contained in the slit plane, so the principal branch of the logarithm is continuous on the spectrum of `u` (or equivalently, `Complex.arg` is continuous on the spectrum). The continuous functional calculus can then be used to define a selfadjoint element `x` such that `u = exp (I • x)`. Moreover, there is a relatively nice relationship between the norm of `x` and the norm of `u - 1`, namely `‖u - 1‖ ^ 2 = 2 * (1 - cos ‖x‖)`. In fact, these maps `u ↦ x` and `x ↦ u` establish a partial homeomorphism between `ball (1 : unitary A) 2` and `ball (0 : selfAdjoint A) π`. The map `t ↦ exp (t • (I • x))` constitutes a path from `1` to `u`, showing that unitary elements sufficiently close (i.e., within a distance `2`) to `1 : unitary A` are path connected to `1`. This property can be translated around the unitary group to show that if `u v : unitary A` are unitary elements with `‖u - v‖ < 2`, then there is a path joining them. In fact, this path has the property that it lies within `closedBall u ‖u - v‖`, and consequently any ball of radius `δ < 2` in `unitary A` is path connected. Therefore, the unitary group is locally path connected. Finally, we provide the standard characterization of the path component of `1 : unitary A` as finite products of exponential unitaries. --- - [ ] depends on #30301 - [ ] depends on #30305 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-analysis 350/0 Mathlib.lean,Mathlib/Analysis/CStarAlgebra/Spectrum.lean,Mathlib/Analysis/CStarAlgebra/Unitary/Connected.lean 3 4 ['dupuisf', 'github-actions', 'mathlib4-merge-conflict-bot'] nobody
0-54303
15 hours ago
1-8405
1 day ago
1-16334
1 day
30308 j-loreaux
author:j-loreaux
feat: C⋆-algebras are spanned by their unitary elements --- - [ ] depends on: #30301 - [ ] depends on: #30305 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-analysis 107/0 Mathlib.lean,Mathlib/Analysis/CStarAlgebra/Unitary/Span.lean 2 5 ['dupuisf', 'github-actions', 'j-loreaux', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] nobody
0-49961
13 hours ago
1-8480
1 day ago
1-11534
1 day
29322 xroblot
author:xroblot
feat(RingTheory/Localization/AtPrime): bijection between prime ideals Let `R ⊆ S` be an extension of rings and `p` be a prime ideal of `R`. Denote by `Rₚ` the localization of `R` at the complement of `p` and by `Sₚ` the localization of `S` at the (image) of the complement of `p`. In this PR, we study the extension `Rₚ ⊆ Sₚ` and the relation between the (nonzero) prime ideals of `Sₚ` and the prime ideals of `S` above `p`. In particular, we prove that (under suitable conditions) they are in bijection. In a following PR #27706, we prove that the residual degree and ramification index are preserved by this bijection. Note. The new file `RingTheory.Localization.AtPrime.Extension` is imported in `RingTheory.Trace.Quotient` because one function from the latter was moved to the former, but the plan is eventually to move the isomorphisms proved in `RingTheory.Trace.Quotient` to `RingTheory.Localization.AtPrime.Basic` and `RingTheory.Localization.AtPrime.Extension` where they belong. This will be done in #27706. --- t-ring-theory 147/8 Mathlib.lean,Mathlib/RingTheory/DedekindDomain/Instances.lean,Mathlib/RingTheory/Ideal/Maps.lean,Mathlib/RingTheory/Ideal/Over.lean,Mathlib/RingTheory/Localization/AtPrime/Extension.lean,Mathlib/RingTheory/Trace/Quotient.lean 6 11 ['chrisflav', 'github-actions', 'xroblot'] chrisflav
assignee:chrisflav
0-38901
10 hours ago
0-38901
10 hours ago
33-41871
33 days
26104 xroblot
author:xroblot
feat(NumberField/IsCM): compute ratio of regulators This PR continues the work from #23696. Compute the ratio between the regulator of `K` and the regulator of its maximal real subfield. --- - [x] depends on: #23694 - [x] depends on: #26075 - [x] depends on: #26108 t-number-theory 72/1 Mathlib/NumberTheory/NumberField/CMField.lean,Mathlib/NumberTheory/NumberField/InfinitePlace/TotallyRealComplex.lean 2 11 ['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'tb65536', 'xroblot'] tb65536
assignee:tb65536
0-38160
10 hours ago
0-38160
10 hours ago
8-4796
8 days
28604 alreadydone
author:alreadydone
chore(Algebra/Ring/Defs): add two classes (minimally invasive version) Add the missing `NonAssocComm(Semi)ring` classes and add some missing instances between existing classes. Contrary to #28532, the approach here doesn't add any new `extends`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
59/17 Mathlib/Algebra/Colimit/DirectLimit.lean,Mathlib/Algebra/Ring/Defs.lean,Mathlib/LinearAlgebra/CliffordAlgebra/Basic.lean 3 20 ['alreadydone', 'github-actions', 'leanprover-bot', 'leanprover-community-mathlib4-bot', 'riccardobrasca'] riccardobrasca
assignee:riccardobrasca
0-34474
9 hours ago
7-66696
7 days ago
8-39314
8 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
label:t-algebra$
94/0 Mathlib/LinearAlgebra/Matrix/Transvection.lean,MathlibTest/matrix.lean 2 2 ['github-actions', 'riccardobrasca', 'zach1502'] riccardobrasca
assignee:riccardobrasca
0-34363
9 hours ago
16-78784
16 days ago
17-57848
17 days
30059 AntoineChambert-Loir
author:AntoineChambert-Loir
feat(Mathlib/Algebra/QuadraticAlgebra): norm, star structure on quadratic alg. Define the norm and the star structure on a quadratic algebra. Application to the units and the zero divisors. The file `Mathlib.Algebra.QuadraticAlgebra.lean` has been renamed to `Mathlib.Algebra.QuadraticAlgebra/Defs.lean`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
416/1 Mathlib.lean,Mathlib/Algebra/Group/Basic.lean,Mathlib/Algebra/QuadraticAlgebra.lean,Mathlib/Algebra/QuadraticAlgebra/Basic.lean 4 30 ['AntoineChambert-Loir', 'eric-wieser', 'github-actions', 'j-loreaux', 'riccardobrasca'] riccardobrasca
assignee:riccardobrasca
0-34309
9 hours ago
6-69052
6 days ago
10-60812
10 days
26956 mariainesdff
author:mariainesdff
feat(RingTheory/DividedPowers/Basic): add divided power structure on pZp We construct a divided power structure on the ideal `(p) ⊆ ℤ_[p]`, given by the family of maps `fun n x ↦ x^n / n!`. Co-authored-by: @AntoineChambert-Loir --- - [x] depends on: #22322 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory 214/0 Mathlib.lean,Mathlib/NumberTheory/Padics/PadicVal/Basic.lean,Mathlib/RingTheory/DividedPowers/Padic.lean 3 25 ['github-actions', 'loefflerd', 'mariainesdff', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] loefflerd and mattrobball
assignee:loefflerd assignee:mattrobball
0-34185
9 hours ago
1-10223
1 day ago
79-23284
79 days
30345 vlad902
author:vlad902
feat(Order): replace the implementation of `Set.chainHeight` `Set.chainHeight` is unused in Mathlib--it was a previous attempt to formalize heights for preorders before `Order.height` came into use. The current implementation `Set.chainHeight` is previously defined for Sets that had an `LT` order but it's behavior was unexpected for relations that were not strict orders, e.g. singleton sets with a reflexive relation would have infinite height. LE is such a relation so this implementation is very limited in what it could be used for. I replace it with an implementation that: - Is defined for arbitrary relations instead of using `[LT]`. - Uses `IsChain` instead of `List.IsChain` for defining chains. This is equivalent for transitive relations, but behaves differently for non- transitive relations--it requires that all elements in the set are comparable instead of just comparability between neighboring elements in the List. This makes the definition better behaved for e.g. reflexive relations and better matches the definition of chain height typically used in the literature. The API has been slimmed down but what remains largely matches the previous API. Discussed on [Zulip](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Definitions.20for.20chain.20height.2Fpartitions/near/542823244) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) large-import t-order 128/294 Mathlib/Order/Height.lean 1 1 ['github-actions'] nobody
0-31702
8 hours ago
0-79557
22 hours ago
0-79602
22 hours
30333 paulorauber
author:paulorauber
feat(Probability): definition of trajMeasure A definition of `trajMeasure` and some basic lemmas. In the context of the Ionescu-Tulcea theorem, `trajMeasure μ₀ κ` corresponds to the distribution of the trajectory obtained by starting with the distribution `μ₀` and then iterating the kernels `κ`. Lemmas `partialTraj_compProd_kernel_eq_traj_map` and `traj_map_eq_kernel` are attributable to @EtienneC30 and some definitions borrow code from @RemyDegenne , who also improved the code considerably. Please let me know if you would like to be co-authors in this pull request. From the LeanBandits project. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-measure-probability 78/1 Mathlib/Probability/Kernel/IonescuTulcea/Traj.lean 1 1 ['github-actions'] EtienneC30
assignee:EtienneC30
0-31071
8 hours ago
0-31071
8 hours ago
1-10401
1 day
29925 jcreinhold
author:jcreinhold
feat(CategoryTheory/MarkovCategory): Add Markov category This PR introduces Markov categories, extending copy-discard categories with natural discard to model categorical probability theory. This PR builds on #29939 and #29919 and was split up from #29657. ## Main additions ### 1. Markov categories (`MarkovCategory`) Extends `CopyDiscardCategory` where discard is natural: `f ≫ ε[Y] = ε[X]` for all morphisms `f : X → Y`. This forces a probabilistic interpretation where morphisms preserve normalization (probability measures sum to 1). ## Mathematical significance Markov categories capture probability theory categorically: - Morphisms: Stochastic processes/Markov kernels - Copy: Perfect correlation (both outputs always equal) - Discard: Marginalization (integrating out variables) - Natural discard: Preservation of total probability The same framework handles finite probability (stochastic matrices), measure-theoretic probability (Markov kernels), and quantum probability (completely positive maps). ## Design decisions - Terminal unit follows from axioms. We prove `unit_terminal` and `unit_isTerminal` rather than assuming them ## Implementation notes - Built on top of `CopyDiscardCategory` per suggestion [#mathlib4 > Markov categories PR @ 💬](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Markov.20categories.20PR/near/539656225) - Includes both computational (`unit_terminal`) and categorical (`unit_isTerminal`) characterizations of the terminal object ## References Cho & Jacobs (2019) and Fritz (2020) [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) - [x] depends on: #29939 new-contributor t-category-theory 171/0 Mathlib.lean,Mathlib/CategoryTheory/MarkovCategory/Basic.lean,MathlibTest/CategoryTheory/MarkovCategory.lean 3 7 ['github-actions', 'jcreinhold', 'joelriou', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] nobody
0-30150
8 hours ago
0-33132
9 hours ago
2-8180
2 days
29868 themathqueen
author:themathqueen
feat(LinearAlgebra/Matrix/PosDef): add `posSemidef_sum` --- - [x] depends on: #29862 - [x] depends on: #29864 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
23/0 Mathlib/LinearAlgebra/Matrix/PosDef.lean 1 3 ['github-actions', 'mathlib4-dependent-issues-bot', 'themathqueen'] nobody
0-30065
8 hours ago
0-31662
8 hours ago
0-31663
8 hours
29824 themathqueen
author:themathqueen
feat(Algebra/Order/Star): add `StarOrderedRing (Π i, A i)` --- - [x] depends on: #29823 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
38/0 Mathlib.lean,Mathlib/Algebra/Order/Star/Pi.lean 2 2 ['github-actions', 'mathlib4-dependent-issues-bot'] nobody
0-24534
6 hours ago
0-27874
7 hours ago
0-28274
7 hours
30340 themathqueen
author:themathqueen
chore(Analysis/SpecialFunctions/CFC/Rpow/Basic): extra TFAE conditions for nonnegativity --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-analysis 46/16 Mathlib/Analysis/SpecialFunctions/ContinuousFunctionalCalculus/Rpow/Basic.lean 1 2 ['github-actions', 'themathqueen'] nobody
0-23214
6 hours ago
0-86057
23 hours ago
0-86188
23 hours
30176 mcdoll
author:mcdoll
feat(Analysis/Distribution): Multiplication of two functions of temperate growth is of temperate growth --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-analysis 57/1 Mathlib/Analysis/Distribution/SchwartzSpace.lean 1 4 ['ADedecker', 'github-actions', 'mcdoll'] nobody
0-23156
6 hours ago
6-2865
6 days ago
6-2903
6 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 41/0 Mathlib.lean,Mathlib/Data/FunLike/Graded.lean 2 1 ['github-actions'] nobody
0-21838
6 hours ago
0-62309
17 hours ago
0-62347
17 hours
30171 smmercuri
author:smmercuri
feat(DedekindDomain/AdicValuation): `le_one` lemmas for `HeightOneSpectrum.valuation` and specialisations to `Rat` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory 54/0 Mathlib/RingTheory/DedekindDomain/AdicValuation.lean 1 1 ['github-actions'] nobody
0-17858
4 hours ago
6-7041
6 days ago
6-7073
6 days
27268 wwylele
author:wwylele
feat: Hahn embedding theorem This proves [Hahn embedding theorem](https://en.wikipedia.org/wiki/Hahn_embedding_theorem), one among the 1000+ theorems project. Note on file location: I originally placed it in Algebra/Order/Group, but got prompted that Algebra can't import Analysis (needed for `Real` being a `Rat`-module` and related fact), so now I moved it under HahnSeries --- This is migrated from #25140 to fork - [x] depends on: #29275 - [x] depends on: #30101 - [x] depends on: #26114 - [x] depends on: #27043 - [x] depends on: #29421 - [x] depends on: #29423 - [x] depends on: #29451 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
122/1 Mathlib.lean,Mathlib/Algebra/Order/Module/HahnEmbedding.lean,Mathlib/RingTheory/HahnSeries/HahnEmbedding.lean,docs/1000.yaml,docs/references.bib 5 8 ['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'wwylele'] nobody
0-17556
4 hours ago
0-17738
4 hours ago
0-18623
5 hours
30324 EtienneC30
author:EtienneC30
feat: introduce covInnerBilin The `covInnerBilin` associated to a measure is the positive semidefinite continuous bilinear form which represents its covariance. --- From BrownianMotion [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-measure-probability 171/1 Mathlib.lean,Mathlib/Probability/Moments/CovInnerBilin.lean,Mathlib/Probability/Moments/CovarianceBilin.lean,Mathlib/Topology/Algebra/Module/StrongTopology.lean 4 1 ['github-actions'] nobody
0-17464
4 hours ago
0-79486
22 hours ago
1-24561
1 day
29946 smmercuri
author:smmercuri
feat(InfinitePlace/Ramification): embeddings of unramified/ramified infinite places satisfy `IsUnmixed/IsMixed` --- - [x] depends on: #29945 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) FLT t-number-theory 64/1 Mathlib/NumberTheory/NumberField/InfinitePlace/Ramification.lean 1 4 ['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'smmercuri', 'xroblot'] alexjbest
assignee:alexjbest
0-15970
4 hours ago
10-28013
10 days ago
10-38093
10 days
30330 Bergschaf
author:Bergschaf
feat(Algebra/Group/Action/Equidecomp): Mathlib's definition of Equidecomposability is equivalent to the standart one using partitions --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) large-import t-algebra
label:t-algebra$
369/1 Mathlib/Algebra/Group/Action/Equidecomp.lean 1 1 ['github-actions'] nobody
0-15550
4 hours ago
1-16481
1 day ago
1-16523
1 day
28330 joelriou
author:joelriou
feat(AlgebraicTopology): the type of non degenerate simplices not in a given subcomplex --- - [x] depends on: #28224 - [x] depends on: #27968 - [x] depends on: #28034 - [x] depends on: #26076 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebraic-topology 86/0 Mathlib.lean,Mathlib/AlgebraicTopology/SimplicialSet/NonDegenerateSimplices.lean,Mathlib/AlgebraicTopology/SimplicialSet/NonDegenerateSimplicesSubcomplex.lean 3 6 ['github-actions', 'joelriou', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] nobody
0-14692
4 hours ago
0-14692
4 hours ago
0-14670
4 hours
30360 Vierkantor
author:Vierkantor
chore(*): rename note 'CategoryTheory universes' to 'category theory universes' Discussed in #23767 but spun off to its own PR to keep the diff smaller. --- - [x] depends on: #23767 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) maintainer-merge t-category-theory t-meta 29/29 Mathlib/CategoryTheory/Adjunction/Opposites.lean,Mathlib/CategoryTheory/Category/Basic.lean,Mathlib/CategoryTheory/Comma/Arrow.lean,Mathlib/CategoryTheory/Comma/Over/Basic.lean,Mathlib/CategoryTheory/Comma/StructuredArrow/Basic.lean,Mathlib/CategoryTheory/Comma/StructuredArrow/Small.lean,Mathlib/CategoryTheory/Core.lean,Mathlib/CategoryTheory/Discrete/Basic.lean,Mathlib/CategoryTheory/EqToHom.lean,Mathlib/CategoryTheory/Functor/Basic.lean,Mathlib/CategoryTheory/Functor/Category.lean,Mathlib/CategoryTheory/Groupoid.lean,Mathlib/CategoryTheory/InducedCategory.lean,Mathlib/CategoryTheory/Iso.lean,Mathlib/CategoryTheory/Limits/Cones.lean,Mathlib/CategoryTheory/Limits/Constructions/Over/Connected.lean,Mathlib/CategoryTheory/Limits/FunctorCategory/Basic.lean,Mathlib/CategoryTheory/Limits/HasLimits.lean,Mathlib/CategoryTheory/Limits/Preserves/Basic.lean,Mathlib/CategoryTheory/Monad/Basic.lean,Mathlib/CategoryTheory/Monad/Kleisli.lean,Mathlib/CategoryTheory/NatTrans.lean,Mathlib/CategoryTheory/Opposites.lean,Mathlib/CategoryTheory/PEmpty.lean,Mathlib/CategoryTheory/PUnit.lean,Mathlib/CategoryTheory/Types/Basic.lean,Mathlib/CategoryTheory/Yoneda.lean,Mathlib/Combinatorics/Quiver/Basic.lean,Mathlib/Data/Opposite.lean 29 6 ['Vierkantor', 'github-actions', 'grunweg', 'joelriou', 'mathlib4-dependent-issues-bot'] nobody
0-14165
3 hours ago
0-14165
3 hours ago
0-24921
6 hours
29347 themathqueen
author:themathqueen
refactor(Algebra/Star/StarAlgHom): let `StarAlgEquiv` extend `StarRingEquiv` instead of `RingEquiv` Instead of having `StarAlgEquiv` extend `RingEquiv` and have properties `map_star'` and `map_smul'`, it now extends `StarRingEquiv` with only `map_smul'`. --- Will add more API in the next PR. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
29/36 Mathlib/Algebra/Star/StarAlgHom.lean,Mathlib/Analysis/CStarAlgebra/CStarMatrix.lean 2 5 ['github-actions', 'leanprover-bot', 'leanprover-community-mathlib4-bot', 'themathqueen'] kbuzzard
assignee:kbuzzard
0-13868
3 hours ago
32-75417
1 month ago
35-11971
35 days
30362 EtienneC30
author:EtienneC30
refactor: make ContinuousLinearMap.id protected As it is for many other kinds of homomorphisms. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) maintainer-merge t-algebra t-topology
label:t-algebra$
20/5 Mathlib/Analysis/Calculus/Conformal/NormedSpace.lean,Mathlib/Analysis/Calculus/FDeriv/Add.lean,Mathlib/Analysis/Calculus/FDeriv/Basic.lean,Mathlib/Analysis/Normed/Operator/Basic.lean,Mathlib/Analysis/Normed/Operator/Bilinear.lean,Mathlib/Analysis/Normed/Operator/Conformal.lean,Mathlib/Analysis/Normed/Operator/NormedSpace.lean,Mathlib/Topology/Algebra/Module/Equiv.lean,Mathlib/Topology/Algebra/Module/LinearMap.lean,Mathlib/Topology/Algebra/Module/LinearMapPiProd.lean 10 6 ['github-actions', 'grunweg'] nobody
0-13847
3 hours ago
0-13847
3 hours ago
0-29807
8 hours
30353 JovanGerb
author:JovanGerb
chore(Topology/ContinuousMap/CompactlySupported): golf `exists_add_nnrealPart_add_eq` This PR shortens the proof of `exists_add_nnrealPart_add_eq`, based on #29866 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) maintainer-merge t-topology easy 3/38 Mathlib/Topology/ContinuousMap/CompactlySupported.lean 1 2 ['github-actions', 'grunweg'] nobody
0-13781
3 hours ago
0-13781
3 hours ago
0-68553
19 hours
30306 joelriou
author:joelriou
chore(CategoryTheory/Presentable/IsCardinalFiltered): fix name The wrong name `isFiltered_of_isCardinalDirected` is fixed: the correct name is `isFiltered_of_isCardinalFiltered`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) maintainer-merge t-category-theory easy 13/10 Mathlib/CategoryTheory/Abelian/GrothendieckCategory/ColimCoyoneda.lean,Mathlib/CategoryTheory/Abelian/GrothendieckCategory/Subobject.lean,Mathlib/CategoryTheory/Presentable/IsCardinalFiltered.lean,Mathlib/CategoryTheory/Presentable/Limits.lean 4 2 ['github-actions', 'grunweg'] nobody
0-13700
3 hours ago
0-13700
3 hours ago
2-3150
2 days
30250 harahu
author:harahu
chore(Algebra): generalize subalgebra operations to semirings Relax Subalgebra operations to work over `CommSemiring` structures instead of demanding commutative rings. --- Found by asking OpenAI Codex to search for low-hanging generalization opportunities. I don't have any usage in mind. Just wanted to explore what Codex would find. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
2/2 Mathlib/Algebra/Algebra/Subalgebra/Operations.lean 1 1 ['github-actions'] nobody
0-13595
3 hours ago
3-83333
3 days ago
3-83371
3 days
30249 vihdzp
author:vihdzp
feat: `IsRoot.mul_div_eq` --- I found myself reaching for this the other day, figured I might as well add it. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) maintainer-merge t-algebra easy
label:t-algebra$
3/1 Mathlib/Algebra/Polynomial/FieldDivision.lean,Mathlib/RingTheory/AdjoinRoot.lean 2 2 ['github-actions', 'grunweg'] nobody
0-13117
3 hours ago
0-13117
3 hours ago
3-85835
3 days
30369 fbarroero
author:fbarroero
feat(Analysis/SpecialFunctions/Log): one trivial fact about posLog This is a trivial fact about `posLog`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) maintainer-merge t-analysis 4/0 Mathlib/Analysis/SpecialFunctions/Log/PosLog.lean 1 2 ['github-actions', 'grunweg'] nobody
0-12744
3 hours ago
0-12745
3 hours ago
0-19949
5 hours
30210 wwylele
author:wwylele
feat(RingTheory/PowerSeries): Multipliable (1 + f i) for when the order tends to infinity As `Summable f` and `Multipliable (1 + f ·)` are often related, this shares the same condition as `summable_of_tendsto_order_atTop_nhds_top` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory 26/0 Mathlib/RingTheory/PowerSeries/PiTopology.lean 1 3 ['CBirkbeck', 'b-mehta', 'github-actions'] nobody
0-11095
3 hours ago
4-78950
4 days ago
4-78985
4 days
30300 chrisflav
author:chrisflav
chore(RingTheory/AdjoinRoot): move `AdjoinRoot.algEquivOfEq` earlier Before this PR it was in `Mathlib.FieldTheory.IntermediateField.Adjoin.Basic` and required `Field K`. This PR moves it to `Mathlib.RingTheory.AdjoinRoot` and replaces the `Field` assumption by `CommRing`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory maintainer-merge 37/34 Mathlib/FieldTheory/IntermediateField/Adjoin/Basic.lean,Mathlib/RingTheory/AdjoinRoot.lean 2 3 ['github-actions', 'grunweg'] nobody
0-10867
3 hours ago
0-10867
3 hours ago
2-7132
2 days
30197 luigi-massacci
author:luigi-massacci
feat: bundled C^n maps supported in a fixed compact set Add a type of n-times continuously differentiable maps supported in a fixed compact set and related notation. Co-authored by: @ADedecker --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) maintainer-merge t-analysis 163/0 Mathlib.lean,Mathlib/Analysis/Distribution/ContDiffMapSupportedIn.lean 2 62 ['ADedecker', 'github-actions', 'grunweg', 'luigi-massacci', 'mcdoll'] nobody
0-10756
2 hours ago
0-10756
2 hours ago
4-18709
4 days
30268 euprunin
author:euprunin
chore(Order/Interval/Set): golf entire `{Icc,Ici,Ico,Iic,Iio,Ioc,Ioi,Ioo}_coe` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) maintainer-merge t-order 12/24 Mathlib/Order/Interval/Set/WithBotTop.lean 1 4 ['github-actions', 'grunweg'] nobody
0-10524
2 hours ago
0-11615
3 hours ago
3-17120
3 days
27066 vasnesterov
author:vasnesterov
feat(Tactic/Order): frontend for `order` * Support `order [h1, h2]` and `order only [h1, h2]` syntax. * Split conjunctions while extracting facts from the context. E.g. hypotheses in the form `A ∧ B` are converted into two facts `A` and `B`. * Similarly, extract facts from existential quantifiers in the hypotheses. --- - [x] depends on: #26354 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) This PR continues the work from #22073. Original PR: https://github.com/leanprover-community/mathlib4/pull/22073 t-meta 100/40 Mathlib.lean,Mathlib/Tactic/Linarith/Frontend.lean,Mathlib/Tactic/Order.lean,Mathlib/Tactic/Order/CollectFacts.lean,Mathlib/Util/ElabWithoutMVars.lean,MathlibTest/order.lean 6 28 ['JovanGerb', 'Vierkantor', 'github-actions', 'mathlib4-dependent-issues-bot', 'vasnesterov'] alexjbest
assignee:alexjbest
0-9451
2 hours ago
0-20319
5 hours ago
86-37741
86 days
29713 jessealama
author:jessealama
feat (Algebra/Homology): add Euler–Poincaré formula This PR adds the Euler characteristic for chain complexes and proves the Euler-Poincaré formula relating the alternating sum of chain dimensions to the alternating sum of homology dimensions. ### Main definitions (in `EulerCharacteristic.lean`) * `ChainComplex.boundedEulerChar`: The Euler characteristic over a finite set * `ChainComplex.eulerChar`: The Euler characteristic as an infinite sum * `ChainComplex.homologyBoundedEulerChar`: The homological Euler characteristic over a finite set * `ChainComplex.homologyEulerChar`: The homological Euler characteristic as an infinite sum Both bounded and infinite definitions work with ℤ-indexed complexes over any ring R. The file also includes theorems relating the formally infinite sums to finite sums when there is finite support: * `ChainComplex.eulerChar_eq_boundedEulerChar`: The infinite Euler characteristic equals the bounded one when the chain complex vanishes outside a finite set * `ChainComplex.homologyEulerChar_eq_homologyBoundedEulerChar`: The infinite homological Euler characteristic equals the bounded one when homology vanishes outside a finite set ### Main result (in `EulerPoincare.lean`) * `ChainComplex.eulerChar_eq_homology_eulerChar`: For ℤ-indexed bounded chain complexes of finite-dimensional modules over a division ring, the alternating sum of chain dimensions equals the alternating sum of homology dimensions. --- Related to: #29639, #29643, #29646 new-contributor t-algebra
label:t-algebra$
444/0 Mathlib.lean,Mathlib/Algebra/Homology/EulerCharacteristic.lean,Mathlib/Algebra/Homology/EulerPoincare.lean 3 19 ['github-actions', 'jessealama', 'joelriou', 'kim-em'] dagurtomas
assignee:dagurtomas
0-8074
2 hours ago
22-14894
22 days ago
23-24744
23 days
30366 sinhp
author:sinhp
feat: The Preliminaries for Locally Cartesian Closed Categories See https://github.com/leanprover-community/mathlib4/pull/21525 This PR defines the basic preliminaries for defining locally cartesian closed categories (LCCCs): `Over.Sigma`, `Over.Reindex` are short-hands for object part of the action of `Over.map` and `Over.pullback`. These are useful for developing consistent notations for locally cartesian closed categories (lcccs). The basic API of `Over.Sigma` (push) and `Over.Reindex` (pull) is developed and we prove that pull-push is isomorphic to the cartesian binary product in the slices. In fact, we prove the stronger statement, namely that the pull-push composition `(Over.pullback Y.hom) ⋙ (Over.map Y.hom)` is naturally isomorphic to the left tensor product functor `Y × _` in `Over X`. This is going to be crucial in our mate-based approach to lcccs. Also, using the calculus of mates we define certain natural isomorphisms involving `Over.star` and `Over.pullback` which will be used 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 343/48 Mathlib/CategoryTheory/Comma/Over/Basic.lean,Mathlib/CategoryTheory/Comma/Over/Pullback.lean,Mathlib/CategoryTheory/Galois/Examples.lean 3 1 ['github-actions'] nobody
0-7192
1 hour ago
0-24047
6 hours ago
0-24092
6 hours
30358 smmercuri
author:smmercuri
style: fix capitalisation `Valued.isOpen_closedball -> Valued.isOpen_closedBall` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) maintainer-merge t-topology easy 7/4 Mathlib/Topology/Algebra/Valued/LocallyCompact.lean,Mathlib/Topology/Algebra/Valued/ValuationTopology.lean 2 4 ['github-actions', 'grunweg'] nobody
0-6529
1 hour ago
0-6529
1 hour ago
0-30785
8 hours
30378 mans0954
author:mans0954
refactor(Order/Hom/Lattice): Use default `initialize_simps_projections` configuration for `LatticeHom`. Use default `initialize_simps_projections` configuration for `LatticeHom`. I'm not sure what was originally intended by the TODO, but this appears to work. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-order 4/7 Mathlib/Order/Hom/Lattice.lean,Mathlib/Order/Hom/WithTopBot.lean 2 1 ['github-actions'] nobody
0-6475
1 hour ago
0-6493
1 hour ago
0-6529
1 hour
30376 urkud
author:urkud
chore(TangentCone): split `uniqueDiffWithinAt_convex` I need the new lemma for #24019 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) maintainer-merge t-analysis 10/7 Mathlib/Analysis/Calculus/TangentCone.lean 1 2 ['github-actions', 'grunweg'] nobody
0-6360
1 hour ago
0-6360
1 hour ago
0-12532
3 hours
30254 harahu
author:harahu
chore(algebra): generalize mul_mem_smul_iff to rings Generalize mul_mem_smul_iff to rings instead of just commutative rings. --- Found by asking OpenAI Codex to search for low-hanging generalization opportunities. I don't have any usage in mind. Just wanted to explore what Codex would find. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra
label:t-algebra$
1/1 Mathlib/Algebra/Algebra/Operations.lean 1 6 ['github-actions', 'grunweg', 'harahu', 'themathqueen'] nobody
0-6282
1 hour ago
3-82640
3 days ago
3-82673
3 days
30307 grunweg
author:grunweg
feat: support coercions in the differential geometry elaborators Generalise the `CMDiff`, `MDiff` and `mfderiv` elaborators (and its friends) to apply to any object which coerces to a function. We can such speak about the smoothness of a `PartialEquiv`, `OpenPartialHomeomorph` (or the future `ClosedPartialHomeomorph` and `PartialHomeomorph`), smooth section or bundled smooth map without the need for a coercion. While at it, add more sections (and section headers) to the test file for the elaborators. --- I have forward-ported this PR to #26221 and not noticed any issues yet. - [x] depends on: #27021 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-differential-geometry t-meta 140/24 Mathlib/Geometry/Manifold/Notation.lean,Mathlib/Lean/Meta/Basic.lean,MathlibTest/DifferentialGeometry/Notation.lean 3 7 ['github-actions', 'grunweg', 'mathlib4-dependent-issues-bot', 'thorimur'] nobody
0-6055
1 hour ago
1-12847
1 day ago
1-12987
1 day
30364 xroblot
author:xroblot
chore(FractionRing): generalize an instance The instance that deduce from a tower of domains `A ⊆ B ⊆ C` that there is a tower `Frac A ⊆ Frac B ⊆ Frac C` can be generalized to `A ⊆ B ⊆ K` implies `Frac A ⊆ Frac B ⊆ K` where `K` is a field (and exactly the same proof works!). --- t-ring-theory 4/4 Mathlib/RingTheory/Localization/FractionRing.lean 1 7 ['github-actions', 'grunweg', 'jcommelin', 'leanprover-bot', 'leanprover-community-mathlib4-bot', 'xroblot'] nobody
0-5225
1 hour ago
0-5225
1 hour ago
0-17556
4 hours
29342 mans0954
author:mans0954
refactor(Analysis/LocallyConvex/AbsConvex): Redefine AbsConvex to use a single ring of scalars Currently the definition of Absolutely Convex in Mathlib is a little unexpected: ``` def AbsConvex (s : Set E) : Prop := Balanced 𝕜 s ∧ Convex ℝ s ``` At the time this definition was formulated, Mathlib's definition of `Convex` required the scalars to be an `OrderedSemiring` whereas the definition of `Balanced` required the scalars to be a `SeminormedRing`. Mathlib didn't have a concept of a semi-normed ordered ring, so a set was defined as `AbsConvex` if it is balanced over a `SeminormedRing` `𝕜` and convex over `ℝ`. Recently the requirements for the definition of `Convex` have been relaxed (#24392, #20595) so it is now possible to use a single scalar ring in common with the literature. Previous discussion: - https://github.com/leanprover-community/mathlib4/pull/17029#discussion_r1782249323 - https://github.com/leanprover-community/mathlib4/pull/26345#discussion_r2287535746 --- - [x] depends on: #29248 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-analysis 51/67 Mathlib/Analysis/Convex/Basic.lean,Mathlib/Analysis/LocallyConvex/AbsConvex.lean,Mathlib/Analysis/LocallyConvex/AbsConvexOpen.lean,Mathlib/Analysis/LocallyConvex/Basic.lean,Mathlib/Analysis/Normed/Module/Dual.lean 5 4 ['github-actions', 'j-loreaux', 'mans0954', 'mathlib4-dependent-issues-bot'] j-loreaux
assignee:j-loreaux
0-3764
1 hour ago
6-82928
6 days ago
6-82916
6 days
30382 joelriou
author:joelriou
feat(CategoryTheory): Guitart exact squares and Kan extensions Given a Guitart exact square `w : T ⋙ R ⟶ L ⋙ B`, we show that pointwise left Kan extensions along `R` give, by composition, pointwise left Kan extensions along `L`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-category-theory 161/12 Mathlib.lean,Mathlib/CategoryTheory/Functor/KanExtension/Pointwise.lean,Mathlib/CategoryTheory/GuitartExact/KanExtension.lean,Mathlib/CategoryTheory/Limits/Final.lean 4 1 ['github-actions'] nobody
0-2940
49 minutes ago
0-3055
50 minutes ago
0-3033
50 minutes
30070 adomani
author:adomani
CI: remove deprecations automatically This workflow automates the removal of deprecated declarations. The action is currently configured to run once a week to automatically remove all deprecations older than 6 months. This is managed by the `remove_deprecated_decls` action and depends on the two files `Mathlib/Tactic/Linter/CommandRanges.lean` and `Mathlib/Tactic/Linter/FindDeprecations.lean`. The action can be manually triggered and there is the option of passing two dates in `YYYY-MM-DD` format or also the more human "3 months ago", as long as it is a valid input for `date -d`. The lean files take care of identifying the declarations with the deprecated attribute whose `since` field is between the given ranges. Those declarations then get automatically removed and, if there are no errors, the bot creates a PR with the changes. These PRs then go, naturally, through CI, where issues related to having removed the deprecated declarations will be picked up. The bot also posts a comment on Zulip mentioning when the PR has been opened. Zulip thread: [#mathlib reviewers > auto-removing oudated deprecations](https://leanprover.zulipchat.com/#narrow/channel/345428-mathlib-reviewers/topic/auto-removing.20oudated.20deprecations/with/541052056) (in reviewers channel) Co-authored-by: Bryan Gin-ge Chen --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) CI 595/0 .github/workflows/remove_deprecated_decls.yml,Mathlib.lean,Mathlib/Tactic.lean,Mathlib/Tactic/Linter/CommandRanges.lean,Mathlib/Tactic/Linter/FindDeprecations.lean,MathlibTest/FindDeprecations.lean 6 26 ['Vierkantor', 'adomani', 'bryangingechen', 'github-actions'] robertylewis
assignee:robertylewis
0-2332
38 minutes ago
8-55214
8 days ago
8-84571
8 days
30377 ocfnash
author:ocfnash
chore: drastically speed up `LieModule.Cohomology.d₂₃` Co-authored-by: Anne C.A. Baanen --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) maintainer-merge t-algebra easy
label:t-algebra$
15/23 Mathlib/Algebra/Lie/Cochain.lean 1 8 ['github-actions', 'grunweg', 'leanprover-bot', 'ocfnash', 'sgouezel'] nobody
0-2229
37 minutes ago
0-6294
1 hour ago
0-11101
3 hours
26588 faenuccio
author:faenuccio
feat(Algebra/GroupWithZero/WithZero): add the multiplicative embedding with zero from the range We extend the embedding of the range of a `MonoidWithZeroHom` to the codomain by enriching it with the structure of an ordered, multiplicative embedding. In passing, we extend some results about the embedding of `WithZero` of the units of a group with zero, to the group itself. Co-authored by: María Inés de Frutos Fernández @mariainesdff --- - [x] depends on: #29594 - [x] depends on: #29644 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-order t-algebra
label:t-algebra$
110/3 Mathlib.lean,Mathlib/Algebra/GroupWithZero/Range.lean,Mathlib/Algebra/Order/GroupWithZero/Range.lean,Mathlib/Algebra/Order/GroupWithZero/WithZero.lean 4 90 ['YaelDillies', 'eric-wieser', 'faenuccio', 'github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'pechersky'] YaelDillies
assignee:YaelDillies
0-2098
34 minutes ago
0-82713
22 hours ago
32-22629
32 days

New contributors' PRs on the review queue

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
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 13/0 Mathlib/MeasureTheory/PiSystem.lean 1 13 ['EtienneC30', 'KiringYJ', 'github-actions', 'ocfnash'] RemyDegenne
assignee:RemyDegenne
62-62489
2 months ago
70-12138
2 months ago
96-86374
96 days
27000 gasparattila
author:gasparattila
feat(Analysis/Normed/Group/Quotient): isometric versions of isomorphisms This PR adds an isometric version of the third isomorphism theorem for groups and modules. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) large-import new-contributor t-analysis 49/2 Mathlib/Analysis/Normed/Group/Quotient.lean 1 1 ['github-actions'] urkud
assignee:urkud
58-62501
1 month ago
90-15228
2 months ago
90-15272
90 days
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 6/0 Mathlib/Analysis/InnerProductSpace/PiL2.lean 1 1 ['github-actions'] urkud
assignee:urkud
52-62481
1 month ago
59-75717
1 month ago
59-75755
59 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 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 1 ['github-actions'] awainverse
assignee:awainverse
50-62504
1 month ago
61-80973
2 months ago
61-81010
61 days
28186 Sebi-Kumar
author:Sebi-Kumar
feat(Topology/Homotopy/Path): Add IsEquiv instance for Path.Homotopic Add `instance : IsEquiv (Path x₀ x₁) Homotopic` to the library. Allow use of lemmas like `of_eq` when proving two paths are homotopic. --- To provide additional context, I am relatively new to contributing to Mathlib, and I am doing so as a part of the Fields Undergraduate Summer Research Program hosted at the University of Western Ontario and supervised by Chris Kapulkin and Daniel Carranza. My goal is to prove that the `n`-sphere is simply connected for `n > 1`. Also, I am not super familiar with `IsEquiv` and when it should/shouldn't be used. I just wanted to use a lemma like `Path.Homotopic.of_eq` at one point while working on my code, and thought this was the best way to add such a result to the library. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-topology 5/0 Mathlib/Topology/Homotopy/Path.lean 1 4 ['Sebi-Kumar', 'github-actions', 'kckennylau'] PatrickMassot
assignee:PatrickMassot
50-62501
1 month ago
60-7431
1 month ago
60-7471
60 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
label:t-algebra$
88/0 Mathlib.lean,Mathlib/Algebra/MvPolynomial/Irreducible.lean 2 5 ['alreadydone', 'github-actions', 'mbkybky'] alreadydone
assignee:alreadydone
47-8898
1 month ago
83-37344
2 months ago
83-37380
83 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 16/0 Mathlib/Combinatorics/SimpleGraph/Trails.lean 1 6 ['IvanRenison', 'github-actions', 'vlad902'] kmill
assignee:kmill
43-24745
1 month ago
135-68271
4 months ago
135-68317
135 days
28602 gmcninch-tufts
author:gmcninch-tufts
feat(Algebra/Polynomial/Module): prove equivalence of a certain tensor product with PolynomialModule For a commutative ring `R` and an `R`-module `M`, construct an equivalence between the `R[X]`-modules `R[X] ⊗[R] M` and `PolynomialModule R M`. This equivalence enables application of some base-change results to `PolynomialModule R M` . --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-algebra
label:t-algebra$
210/0 Mathlib.lean,Mathlib/Algebra/Polynomial/Module/TensorProduct.lean 2 1 ['github-actions'] jcommelin
assignee:jcommelin
37-62501
1 month ago
52-11577
1 month ago
52-11614
52 days
28906 gasparattila
author:gasparattila
feat(Topology/Algebra/Module): `prod` and `coprod` as `ContinuousLinearEquiv`s --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-topology 36/5 Mathlib/Topology/Algebra/Module/LinearMapPiProd.lean,Mathlib/Topology/Algebra/Module/StrongTopology.lean 2 1 ['github-actions'] jcommelin
assignee:jcommelin
35-62507
1 month ago
45-2674
1 month ago
45-2707
45 days
26790 FlAmmmmING
author:FlAmmmmING
feat(Combinatorics/Enumerative/Bell.lean): define standard Bell number --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-combinatorics 46/1 Mathlib/Combinatorics/Enumerative/Bell.lean 1 11 ['AntoineChambert-Loir', 'FlAmmmmING', 'eric-wieser', 'github-actions', 'kckennylau', 'madvorak'] awainverse
assignee:awainverse
35-44777
1 month ago
96-7903
3 months ago
96-7941
96 days
26986 WangYiran01
author:WangYiran01
feat(Partition): add bijection for partitions with max part ≤ r ## Summary This PR adds a new theorem `partition_max_equals_bound` to `Mathlib.Combinatorics.Enumerative.Partition`. It constructs a bijection between: - The set of partitions of `n` in which `r ∈ π.parts` and all parts are `≤ r`, and - The set of partitions of `n - r` whose largest part is at most `r`. This provides a constructive proof via removing/adding `r` from/to the partition multiset, in line with classical enumerative combinatorics. ## Implementation notes - The proof uses `Multiset.erase` and `Multiset.cons` with basic properties of `sum`, `sup`, and `Partition` structures. - The bijection is implemented explicitly via `f` and `g`, and proven mutually inverse via `Subtype.ext`. ## Linting - [x] Passes `lake build` - [x] Linter clean (no commandStart or longLine issues) ## Author Contributed by Yiran Wang. new-contributor t-combinatorics 85/0 Mathlib/Combinatorics/Enumerative/Partition.lean 1 3 ['WangYiran01', 'github-actions'] b-mehta
assignee:b-mehta
35-41311
1 month ago
90-32463
2 months ago
90-32499
90 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 52 ['b-mehta', 'espottesmith', 'github-actions', 'jt496', 'lauramonk', 'mathlib4-merge-conflict-bot'] b-mehta
assignee:b-mehta
34-28554
1 month ago
34-28554
1 month ago
40-14737
40 days
29040 PMKielstra
author:PMKielstra
feat: trapezoidal rule for integration This PR defines the trapezoidal rule and proves the standard error bound on it in terms of bounds on the second derivative. I have vague plans of using this plus interval arithmetic to develop a tactic that can automatically close goals of the form `\integral x in a..b, f x < y` or similar. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-measure-probability 273/0 Mathlib.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral/Basic.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral/TrapezoidalRule.lean 3 40 ['PMKielstra', 'github-actions', 'tb65536'] kex-y
assignee:kex-y
33-62504
1 month ago
42-69397
1 month ago
42-69834
42 days
26453 jburroni
author:jburroni
feat(Data/PNat/Basic): add order-related instances to PNat Add `SuccAddOrder ℕ+` and `NoMaxOrder ℕ+` instances. This allows, for example, the use of lemmas related to `Intervals` built with ℕ+. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data new-contributor 31/0 Mathlib.lean,Mathlib/Data/PNat/Order.lean 2 14 ['Ruben-VandeVelde', 'eric-wieser', 'github-actions', 'jburroni', 'vihdzp'] ericrbg
assignee:ericrbg
31-1970
1 month ago
31-6974
1 month ago
101-9284
101 days
27292 gasparattila
author:gasparattila
feat: asymptotic cone of a set This PR defines the asymptotic cone of a set in a normed affine space and proves its main properties. This is partial progress towards showing that an unbounded finite-dimensional convex set contains a ray. --- - [x] depends on: #27221 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) maintainer-merge new-contributor t-analysis 466/0 Mathlib.lean,Mathlib/Analysis/Normed/Affine/AsymptoticCone.lean,Mathlib/Order/Filter/Map.lean,Mathlib/Topology/Algebra/AsymptoticCone.lean 4 45 ['AntoineChambert-Loir', 'YaelDillies', 'gasparattila', 'github-actions', 'mathlib4-dependent-issues-bot'] YaelDillies
assignee:YaelDillies
22-44044
22 days ago
65-5937
2 months ago
79-23470
79 days
29437 NotWearingPants
author:NotWearingPants
feat(Data/Seq): add Seq.subsequence and prove basic theorems about it I added `Seq.subsequence` to compose a sequence with a monotone function, creating a subsequence. Aliased to `Seq.comp` since it's a composition. I also added `Nat.le_induction_step_iff` which is needed to prove a subsequence is a sequence. This proves the comment at the top of `Defs.lean` that says "if `f n = none`, then `f m = none` for all `m ≥ n`" while `IsSeq` only talks about `n+1`. For completion I added the same statement for `Int`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) large-import t-data new-contributor 114/0 Mathlib/Data/Int/Init.lean,Mathlib/Data/Nat/Init.lean,Mathlib/Data/Seq/Basic.lean,Mathlib/Data/Seq/Defs.lean 4 2 ['github-actions', 'mathlib4-merge-conflict-bot'] nobody
22-23288
22 days ago
22-23309
22 days ago
31-10798
31 days
26129 LessnessRandomness
author:LessnessRandomness
feat(Geometry/Euclidean/Angle/Unoriented): triangle inequality for angles This PR continues the work from #24206. Original PR: https://github.com/leanprover-community/mathlib4/pull/24206 new-contributor t-euclidean-geometry 203/16 Mathlib.lean,Mathlib/Analysis/Fourier/FiniteAbelian/Orthogonality.lean,Mathlib/Analysis/InnerProductSpace/Basic.lean,Mathlib/Analysis/InnerProductSpace/PiL2.lean,Mathlib/Geometry/Euclidean/Angle/Unoriented/Affine.lean,Mathlib/Geometry/Euclidean/Angle/Unoriented/Basic.lean,Mathlib/Geometry/Euclidean/Angle/Unoriented/TriangleInequality.lean,Mathlib/Geometry/Manifold/Instances/Sphere.lean 8 76 ['JovanGerb', 'LessnessRandomness', 'Timeroot', 'github-actions', 'jsm28', 'mathlib4-merge-conflict-bot', 'themathqueen'] jsm28
assignee:jsm28
22-4125
22 days ago
34-67242
1 month ago
110-8633
110 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 1 ['github-actions'] nobody
17-18567
17 days ago
22-25100
22 days ago
22-25146
22 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 1310/0 Archive.lean,Archive/Imo/Imo2025Q1.lean 2 2 ['github-actions', 'mathlib4-merge-conflict-bot'] dwrensha
assignee:dwrensha
15-25618
15 days ago
20-45090
20 days ago
52-70196
52 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 62/0 Mathlib.lean,Mathlib/Combinatorics/Digraph/Orientation.lean,Mathlib/Combinatorics/Digraph/Tournament.lean 3 5 ['JaafarTanoukhi', 'NotWearingPants', 'Rida-Hamadani', 'github-actions'] kmill
assignee:kmill
15-5751
15 days ago
45-82388
1 month ago
45-82422
45 days
28967 utkuokur
author:utkuokur
refactor(Combinatorics/SimpleGraph/Walk): simplify proof of "support_tail_of_not_nil" The proof of the lemma named "support_tail_of_not_nil" is shortened. Since "support_tail" is not needed anymore, it is removed. @[deprecated (since := "2025-08-26")] sign is added for the removed "support_tail". The library references to "support_tail" are replaced with "support_tail_of_not_nil". To keep [@simp] on "cons_support_tail" and avoid the linter error, the [@simp] of "support_tail_of_not_nil" (previously on "support_tail") is removed. There might be a better way that I am missing, to deal with the linter error. --- Additionally, a merge conflict with `master` was resolved by keeping the generalized `support_tail_of_not_nil` and reintroducing `support_tail` as a deprecated alias for compatibility. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-combinatorics 7/10 Mathlib/Combinatorics/SimpleGraph/Hamiltonian.lean,Mathlib/Combinatorics/SimpleGraph/Walk.lean 2 3 ['github-actions', 'mathlib4-merge-conflict-bot', 'themathqueen'] awainverse
assignee:awainverse
14-83465
14 days ago
30-77637
1 month ago
44-7149
44 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 476/0 Mathlib.lean,Mathlib/Combinatorics/Digraph/Maps.lean 2 1 ['github-actions'] nobody
14-32930
14 days ago
15-6033
15 days ago
15-6073
15 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 97/0 Mathlib/GroupTheory/DoubleCoset.lean 1 16 ['Ruben-VandeVelde', 'WilliamCoram', 'github-actions', 'mathlib4-merge-conflict-bot'] mariainesdff
assignee:mariainesdff
14-27131
14 days ago
21-2776
21 days ago
79-68652
79 days
29362 stepanholub
author:stepanholub
feat:(Data/List) add the notion of period of List and prove the Periodicity Lemma Add the concept of the period of a List (word, sequence) which is missing, and prove its basic nontrivial property describing under which conditions list can have two periods known as the Periodicity Lemma (aka Fine-Wilf Theorem). --- t-data new-contributor 227/0 Mathlib.lean,Mathlib/Data/List/PeriodicityLemma.lean 2 125 ['Ruben-VandeVelde', 'Timeroot', 'fpvandoorn', 'github-actions', 'madvorak', 'plp127', 'stepanholub', 'wwylele'] nobody
10-81131
10 days ago
14-83945
14 days ago
32-80142
32 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 28/0 Mathlib/Data/Rat/Lemmas.lean 1 14 ['github-actions', 'sinianluoye', 'themathqueen'] pechersky
assignee:pechersky
9-62492
9 days ago
64-62079
2 months ago
65-3725
65 days
28077 ShreckYe
author:ShreckYe
feat(Data/Finset/Card): add some more Pigeonhole Principle theorems `exists_ne_map_eq_of_card_image_lt` and `not_injOn_of_card_image_lt` `exists_ne_map_eq_of_card_image_lt` is a special case of `exists_ne_map_eq_of_card_lt_of_maps_to` where `t` is `s.image f`, and `not_injOn_of_card_image_lt` is its variant using `Set.InjOn`. I ran into some cases where such theorems would save me some time. t-data new-contributor 10/0 Mathlib/Data/Finset/Card.lean 1 4 ['ShreckYe', 'github-actions', 'themathqueen'] pechersky
assignee:pechersky
9-62491
9 days ago
63-28569
2 months ago
63-28609
63 days
28119 JasperMS
author:JasperMS
feat(Data/Set/Pairwise): prove pairwise results for Chains, move `Set.pairwise_iUnion₂` Initiate a new file `Data/Set/Pairwise/Chain.lean` which makes some `Pairwise` results available to the `IsChain` predicate. In the process, move `Set.pairwise_iUnion₂` to group it with similar results. Perform some variable harmonization. Part of Carleson, original result by Edward van de Meent. Moves: - Set.pairwise_iUnion₂: from Data.Set.Lattice to Data.Set.Pairwise.Lattice --- This PR was discussed and advice was given in [#mathlib4 > Novice questions on style and structure](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Novice.20questions.20on.20style.20and.20structure/with/533462814). Many thanks to those who helped me out! Mathlib PRs are still new to me, so please point out where I can improve! [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) carleson t-data new-contributor 56/12 Mathlib.lean,Mathlib/Data/Set/Lattice.lean,Mathlib/Data/Set/Pairwise/Chain.lean,Mathlib/Data/Set/Pairwise/Lattice.lean 4 11 ['JasperMS', 'Ruben-VandeVelde', 'edegeltje', 'github-actions'] pechersky
assignee:pechersky
9-62490
9 days ago
62-15294
2 months ago
62-15729
62 days
29253 FernandoChu
author:FernandoChu
feat(CategoryTheory): (Co)limits in preorders Characterize (co)limits in preorders as glbs/lubs, plus some other instances. new-contributor t-category-theory 151/13 Mathlib/CategoryTheory/Discrete/Basic.lean,Mathlib/CategoryTheory/Limits/Preorder.lean 2 12 ['FernandoChu', 'github-actions', 'joelriou'] joelriou
assignee:joelriou
8-33782
8 days ago
8-33786
8 days ago
35-32422
35 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 391/68 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 14 ['fweth', 'github-actions', 'joelriou', 'leanprover-community-bot-assistant', 'mathlib4-merge-conflict-bot'] joelriou
assignee:joelriou
7-62509
7 days ago
32-13272
1 month ago
51-71833
51 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 401/0 Mathlib.lean,Mathlib/Dynamics/BirkhoffSum/Pointwise.lean 2 13 ['D-Thomine', 'github-actions', 'leanprover-community-bot-assistant', 'lua-vr', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] urkud
assignee:urkud
7-30007
7 days ago
44-48850
1 month ago
51-18318
51 days
29935 ineol
author:ineol
fix: cache fails when Mathlib is a nightly dependency Cache should on check for the nightly-testing remote when it is run from the Mathlib root and not from a repo which depends on Mathlib. Fixes #28594 --- I don't know how to test this fix since it would need to be in a nightly release, but at least it is working when ran from from tip of master. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor CI 3/3 Cache/Requests.lean 1 3 ['github-actions', 'ineol', 'robin-carlier'] kim-em
assignee:kim-em
7-20167
7 days ago
7-20167
7 days ago
15-30810
15 days
30141 shalliso
author:shalliso
fix(Topology/Baire/Lemmas): fix index type in isMeagre_iUnion The index set ι needs to be of type Sort* instead of type Type* in isMeagre_iUnion otherwise I get the following message when I try to use it: typeclass instance problem is stuck, it is often due to metavariables Countable ?m.27 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-topology 1/1 Mathlib/Topology/GDelta/Basic.lean 1 1 ['github-actions'] nobody
6-75215
6 days ago
6-75228
6 days ago
6-75263
6 days
29728 ADA-Projects
author:ADA-Projects
feat(Topology/KrullDimension): add subspace dimension inequality This PR extends topological Krull dimension theory with basic results about subspaces. - Add mapIrreducibleClosed function for canonical maps between irreducible closed sets - Prove injectivity and strict monotonicity of these maps - Establish partial order structure on IrreducibleCloseds - Prove topKrullDim_subspace_le theorem showing dim(Y) ≤ dim(X) for subspaces **Update (per reviewer feedback):** Reorganized code structure as requested: - Moved `IrreducibleCloseds` extensions from `KrullDimension.lean` to `Sets/Closeds.lean` - This includes `PartialOrder` instance, `map` functions, and embedding lemmas - Better modularity: other files can now use `IrreducibleCloseds` without importing Krull dimension theory The main result `topologicalKrullDim_subspace_le` remains the same - any subspace Y has dim(Y) ≤ dim(X). Some sections of this code (and documentation) were generated with the help of Gemini. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-topology 146/20 Mathlib/Topology/KrullDimension.lean,Mathlib/Topology/Sets/Closeds.lean 2 9 ['ADA-Projects', 'fpvandoorn', 'github-actions', 'kim-em'] PatrickMassot
assignee:PatrickMassot
6-62505
6 days ago
14-31945
14 days ago
14-48666
14 days
30069 IvanRenison
author:IvanRenison
feat(Combinatorics/SimpleGraph): add lemma `IsTree.dist_ne_of_adj` and necessary lemmas This contribution was created as part of the Utrecht Summerschool "Formalizing Mathematics in Lean" in July 2025. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-combinatorics 34/0 Mathlib/Combinatorics/SimpleGraph/Acyclic.lean 1 7 ['github-actions', 'themathqueen', 'vlad902'] nobody
6-36197
6 days ago
10-9292
10 days ago
10-15044
10 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 9/4 Mathlib/Combinatorics/SimpleGraph/Basic.lean 1 1 ['github-actions'] nobody
6-28239
6 days ago
6-28247
6 days ago
6-28282
6 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 227/0 Mathlib.lean,Mathlib/Geometry/Manifold/PrincipalFiberBundle/PrincipalGBundle.lean 2 5 ['github-actions', 'grunweg'] nobody
6-27187
6 days ago
6-40161
6 days ago
7-33114
7 days
30163 NotWearingPants
author:NotWearingPants
feat(Data/Set/Lattice): useful equivalences of `biUnion` and `biInter` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data new-contributor 25/0 Mathlib/Data/Set/Lattice.lean 1 1 ['github-actions'] nobody
6-17353
6 days ago
6-17353
6 days ago
6-17404
6 days
27400 dleijnse
author:dleijnse
feat: define geometrically reduced algebras Define geometrically reduced algebras, and prove that if all finitely generated subalgebras of an algebra `A` are geometrically reduced, then `A` is geometrically reduced. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-algebra
label:t-algebra$
117/0 Mathlib.lean,Mathlib/RingTheory/Adjoin/FG.lean,Mathlib/RingTheory/Flat/Basic.lean,Mathlib/RingTheory/Nilpotent/Defs.lean,Mathlib/RingTheory/Nilpotent/GeometricallyReduced.lean,Mathlib/RingTheory/TensorProduct/Basic.lean 6 72 ['dleijnse', 'github-actions', 'joelriou', 'kckennylau'] joelriou
assignee:joelriou
6-16458
6 days ago
6-16495
6 days ago
73-28308
73 days
29759 NotWearingPants
author:NotWearingPants
feat(Analysis/SpecificLimits/Fibonacci): prove that the ratio of consecutive Fibonacci numbers tends to the golden ratio --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) maintainer-merge new-contributor t-analysis 36/0 Mathlib.lean,Mathlib/Analysis/SpecificLimits/Fibonacci.lean 2 7 ['NotWearingPants', 'Ruben-VandeVelde', 'github-actions', 'kckennylau'] nobody
6-13196
6 days ago
6-13197
6 days ago
13-68574
13 days
29999 jeremypparker
author:jeremypparker
chore(Analysis/Fourier/AddCircle): remove stale comment --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-analysis 0/1 Mathlib/Analysis/Fourier/AddCircle.lean 1 2 ['Ruben-VandeVelde', 'github-actions', 'jeremypparker'] sgouezel
assignee:sgouezel
5-62502
5 days ago
13-31250
13 days ago
13-31284
13 days
30187 CoolRmal
author:CoolRmal
chore(Topology/MeasureTheory/Probability): Rename the file for compactly supported continuous functions. Move two lemmas `essSup_uniformOn_eq_ciSup` and `essInf_cond_count_eq_ciInf` from Mathlib/MeasureTheory/Function/EssSup.lean to Mathlib/Probability/UniformOn.lean in order to avoid warnings for import in the PR [feat(MeasureTheory): Uniqueness of Measures in the Riesz–Markov–Kakutani Representation Theorem](https://github.com/leanprover-community/mathlib4/pull/28061#top). Create a new folder named CompactlySupported and moved two related files into this folder. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) file-removed new-contributor 17/15 Mathlib.lean,Mathlib/MeasureTheory/Function/EssSup.lean,Mathlib/MeasureTheory/Integral/RieszMarkovKakutani/Basic.lean,Mathlib/Probability/Distributions/Fernique.lean,Mathlib/Probability/Moments/IntegrableExpMul.lean,Mathlib/Probability/UniformOn.lean,Mathlib/Topology/ContinuousMap/CompactlySupported/Basic.lean,Mathlib/Topology/ContinuousMap/CompactlySupported/Bounded.lean 8 1 ['github-actions'] nobody
5-39424
5 days ago
5-41391
5 days ago
5-41437
5 days
30206 NotWearingPants
author:NotWearingPants
feat(Combinators/SimpleGraph/Hamiltonian): `p.support.length = Fintype.card α` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-combinatorics easy 8/0 Mathlib/Combinatorics/SimpleGraph/Hamiltonian.lean 1 2 ['NotWearingPants', 'github-actions'] nobody
4-86343
4 days ago
4-86354
4 days ago
4-86396
4 days
30215 NotWearingPants
author:NotWearingPants
feat(Data/List/NodupEquivFin): add equiv with `count = 1` hypothesis --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data new-contributor easy 7/2 Mathlib/Data/List/NodupEquivFin.lean 1 2 ['NotWearingPants', 'github-actions'] nobody
4-73164
4 days ago
4-73164
4 days ago
4-73549
4 days
30214 NotWearingPants
author:NotWearingPants
feat(Data/List/Basic): add `Fin` variants of `*mem_iff_getElem` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data new-contributor easy 11/0 Mathlib/Data/List/Basic.lean 1 2 ['NotWearingPants', 'github-actions'] nobody
4-73093
4 days ago
4-73093
4 days ago
4-73846
4 days
30217 NotWearingPants
author:NotWearingPants
feat(Data/List/GetD): `getD` is surjective iff every element is in the list --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data new-contributor 19/0 Mathlib/Data/List/GetD.lean 1 2 ['github-actions', 'themathqueen'] nobody
4-67995
4 days ago
4-72910
4 days ago
4-72947
4 days
30213 NotWearingPants
author:NotWearingPants
feat(Data/List/GetD): golf and add lemmas for `get` and `getElem?.get` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data new-contributor easy 18/16 Mathlib/Data/List/GetD.lean 1 8 ['NotWearingPants', 'github-actions', 'themathqueen'] nobody
4-66231
4 days ago
4-75372
4 days ago
4-75570
4 days
30225 NotWearingPants
author:NotWearingPants
feat(Combinatorics/SimpleGraph/Walk): `p.getVert` and `p.support.get` have the same range --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-combinatorics 8/0 Mathlib/Combinatorics/SimpleGraph/Walk.lean 1 1 ['github-actions'] nobody
4-61649
4 days ago
4-61663
4 days ago
4-61704
4 days
30232 NotWearingPants
author:NotWearingPants
feat(Combinatorics/SimpleGraph/Connectivity/Subgraph): add `ConnectedComponent.toSubgraph` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-combinatorics easy 17/0 Mathlib/Combinatorics/SimpleGraph/Connectivity/Subgraph.lean 1 2 ['NotWearingPants', 'github-actions'] nobody
4-40494
4 days ago
4-54177
4 days ago
4-54217
4 days
29758 NotWearingPants
author:NotWearingPants
feat(RingTheory/RootsOfUnity): exp(pi * i * q) is a root of unity for rational q --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory new-contributor 28/1 Mathlib/RingTheory/RootsOfUnity/Complex.lean 1 5 ['NotWearingPants', 'Ruben-VandeVelde', 'github-actions', 'kckennylau'] chrisflav
assignee:chrisflav
3-69006
3 days ago
20-67311
20 days ago
20-74312
20 days
30261 NotWearingPants
author:NotWearingPants
feat(Algebra/Ring/Basic): add `a / -b = -a / b` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-algebra
label:t-algebra$
5/3 Mathlib/Algebra/Ring/Basic.lean 1 1 ['github-actions'] nobody
3-61855
3 days ago
3-61867
3 days ago
3-61905
3 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 45/5 Mathlib/NumberTheory/ArithmeticFunction.lean 1 13 ['MichaelStollBayreuth', 'NotWearingPants', 'b-mehta', 'eric-wieser', 'github-actions', 'sun123zxy'] MichaelStollBayreuth
assignee:MichaelStollBayreuth
3-24187
3 days ago
50-49666
1 month ago
50-50630
50 days
30273 NotWearingPants
author:NotWearingPants
feat(NumberTheory/SumTwoSquares): it is decidable whether a number is the sum of two squares Add a `Decidable` instance for the already proven theorem of being the sum of two squares. Try `#eval Finset.range 50 |>.filter (∃ x y, · = x ^ 2 + y ^ 2)` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-number-theory 7/0 Mathlib/NumberTheory/SumTwoSquares.lean 1 1 ['github-actions'] nobody
3-9506
3 days ago
3-9518
3 days ago
3-9560
3 days
30223 NotWearingPants
author:NotWearingPants
feat(Data/List/Nodup): `get` is bijective iff `count = 1` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data maintainer-merge new-contributor 9/0 Mathlib/Data/List/Nodup.lean 1 2 ['Ruben-VandeVelde', 'github-actions'] nobody
2-85736
2 days ago
2-85736
2 days ago
4-64595
4 days
29507 zhuyizheng
author:zhuyizheng
feat(MeasureTheory): derivative integrable functions Part of originally planned #29092. We prove that: * If `f` is monotone on `a..b`, then `f'` is interval integrable on `a..b`. * If `f` has bounded variation on `a..b`, then `f'` is interval integrable on `a..b`. * If `f` is absolutely continuous on `a..b`, then `f'` exists a.e. on `a..b` and is interval integrable on `a..b`. --- - [x] depends on: #29504 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-measure-probability 172/1 Mathlib.lean,Mathlib/Analysis/Calculus/Deriv/Slope.lean,Mathlib/MeasureTheory/Function/AbsolutelyContinuous.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral/DerivIntegrable.lean,Mathlib/MeasureTheory/Integral/Lebesgue/Add.lean 5 3 ['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] nobody
2-65993
2 days ago
3-16811
3 days ago
3-17112
3 days
26985 agjftucker
author:agjftucker
feat(Analysis/Calculus/Implicit): define implicitFunOfProdDomain This PR continues the work from #16743. Original PR: https://github.com/leanprover-community/mathlib4/pull/16743 --- - [x] depends on: #28352 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-analysis 107/4 Mathlib/Analysis/Calculus/Implicit.lean 1 3 ['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] hrmacbeth
assignee:hrmacbeth
2-62502
2 days ago
10-36590
10 days ago
10-38169
10 days
28812 yury-harmonic
author:yury-harmonic
feat(PNat/Factors): add attrs and lemmas --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data new-contributor 42/0 Mathlib/Data/PNat/Factors.lean 1 1 ['github-actions'] pechersky
assignee:pechersky
2-62499
2 days ago
47-11865
1 month ago
47-11898
47 days
29309 LLaurance
author:LLaurance
feat(Combinatorics/SimpleGraph): Nontrivial connected graph contains a vertex that leaves the graph connected if removed This shows that any nontrivial connected graph contains a vertex that, when removed, leaves the graph connected. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) large-import new-contributor t-combinatorics 156/10 Mathlib/Combinatorics/SimpleGraph/Acyclic.lean,Mathlib/Combinatorics/SimpleGraph/Connectivity/Connected.lean,Mathlib/Combinatorics/SimpleGraph/Connectivity/Subgraph.lean,Mathlib/Combinatorics/SimpleGraph/Subgraph.lean,Mathlib/Combinatorics/SimpleGraph/Walk.lean 5 2 ['github-actions', 'mathlib4-merge-conflict-bot'] YaelDillies
assignee:YaelDillies
2-62498
2 days ago
10-24449
10 days ago
31-29066
31 days
30147 NotWearingPants
author:NotWearingPants
feat(NumberTheory/ArithmeticFunction): add some lemmas --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-number-theory 23/1 Mathlib/NumberTheory/ArithmeticFunction.lean 1 3 ['github-actions', 'kckennylau'] nobody
2-12982
2 days ago
6-59121
6 days ago
6-59154
6 days
30216 NotWearingPants
author:NotWearingPants
feat(Data/List/Basic): `get` is surjective iff every element is in the list --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data new-contributor easy 13/0 Mathlib/Data/List/Basic.lean 1 6 ['NotWearingPants', 'github-actions', 'themathqueen'] nobody
2-12181
2 days ago
4-73157
4 days ago
4-73192
4 days
30219 NotWearingPants
author:NotWearingPants
feat(Combinatorics/SimpleGraph/Paths): path iff `p.support.get` is injective --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-combinatorics easy 4/0 Mathlib/Combinatorics/SimpleGraph/Paths.lean 1 3 ['NotWearingPants', 'github-actions', 'themathqueen'] nobody
2-11408
2 days ago
4-70220
4 days ago
4-70254
4 days
30282 NotWearingPants
author:NotWearingPants
chore(Algebra/Order/Ring/Unbundled/Rat): golf --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-algebra
label:t-algebra$
10/26 Mathlib/Algebra/Order/Ring/Unbundled/Rat.lean 1 7 ['Ruben-VandeVelde', 'github-actions', 'kckennylau', 'themathqueen'] nobody
2-10858
2 days ago
2-74203
2 days ago
2-74244
2 days
26909 gasparattila
author:gasparattila
feat(LinearAlgebra/Projectivization/Subspace): correspondence between linear and projective subspaces --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-algebra
label:t-algebra$
65/3 Mathlib/LinearAlgebra/Projectivization/Subspace.lean 1 9 ['Vierkantor', 'eric-wieser', 'gasparattila', 'github-actions'] Vierkantor
assignee:Vierkantor
2-4057
2 days ago
2-7027
2 days ago
92-56148
92 days
30280 NotWearingPants
author:NotWearingPants
chore(Algebra/Order/Monoid/Unbundled/MinMax): golf three lemmas using `grind` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-algebra
label:t-algebra$
3/6 Mathlib/Algebra/Order/Monoid/Unbundled/MinMax.lean 1 1 ['euprunin', 'github-actions'] nobody
2-3353
2 days ago
2-76977
2 days ago
2-77010
2 days
29795 Jlh18
author:Jlh18
refactor: weaken HasPullbacks to HasPullback in Over.Pullback Add an abbreviation `HasPullbackAlong f` to mean that all maps into the codomain of `f` have pullbacks along `f`. As discussed in zulip [#mathlib4 > Hom.HasPullback](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Hom.2EHasPullback/with/541055666) The `HasPullbacks` instance on a category `C` for defining the pullback functor along a map `f : X -> Y` between their over categories can be weakened to just a `HasPullbackAlong` condition on `f`. Dually, for `HasPushout` and undercategories. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-category-theory 35/18 Mathlib/CategoryTheory/Comma/Over/Pullback.lean,Mathlib/CategoryTheory/Limits/Shapes/Pullback/HasPullback.lean 2 22 ['Jlh18', 'chrisflav', 'github-actions', 'kckennylau', 'leanprover-bot', 'mathlib4-merge-conflict-bot', 'peabrainiac'] kim-em
assignee:kim-em
2-2992
2 days ago
5-75109
5 days ago
20-15816
20 days
30263 NotWearingPants
author:NotWearingPants
feat(Algebra/Order/Ring/Unbundled/Rat): exact form for `|q|` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-algebra
label:t-algebra$
12/1 Mathlib/Algebra/Order/Ring/Unbundled/Rat.lean 1 7 ['NotWearingPants', 'github-actions', 'themathqueen', 'wwylele'] nobody
1-81890
1 day ago
3-59283
3 days ago
3-59317
3 days
30205 NotWearingPants
author:NotWearingPants
feat(Combinatorics/SimpleGraph/Walk): `p.getVert` is `p.support.get` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) maintainer-merge new-contributor t-combinatorics easy 10/0 Mathlib/Combinatorics/SimpleGraph/Walk.lean 1 5 ['NotWearingPants', 'Ruben-VandeVelde', 'github-actions', 'themathqueen'] nobody
1-79227
1 day ago
4-29145
4 days ago
5-294
5 days
30220 NotWearingPants
author:NotWearingPants
chore(Data/List/Nodup): golf `nodup_iff_injective_get` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data new-contributor easy 2/5 Mathlib/Data/List/Nodup.lean 1 4 ['NotWearingPants', 'euprunin', 'github-actions'] nobody
1-78573
1 day ago
4-68618
4 days ago
4-68655
4 days
30313 chenson2018
author:chenson2018
feat(Data/List/Sigma): grind annotations, some missing API - `grind` annotations for `List.keys`, `List.NodupKeys`, and `List.lookup`, with some shortening of proofs - upstream `keys_append`, `sublist_dlookup`, and `nodupKeys_middle` from https://github.com/leanprover/cslib/pull/68 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data new-contributor 57/62 Mathlib/Data/List/Sigma.lean 1 5 ['chenson2018', 'eric-wieser', 'github-actions'] nobody
1-68030
1 day ago
1-71358
1 day ago
1-71398
1 day
28818 NotWearingPants
author:NotWearingPants
feat(Data/Setoid/Basic): add theorems about lifting a function to its kernel Currently `ker_lift_injective` and `quotientKerEquivOfRightInverse` lift `f` to `ker f` in their definition. This PR makes this function available as `Setoid.ker_lift f` and adds a few more theorems about it. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data new-contributor easy 29/15 Counterexamples/AharoniKorman.lean,Mathlib/Data/Setoid/Basic.lean,Mathlib/NumberTheory/NumberField/CanonicalEmbedding/FundamentalCone.lean,Mathlib/Topology/Separation/Hausdorff.lean 4 18 ['NotWearingPants', 'eric-wieser', 'github-actions', 'kckennylau', 'mathlib4-merge-conflict-bot'] pechersky
assignee:pechersky
1-62506
1 day ago
26-85996
26 days ago
45-14535
45 days
30315 NotWearingPants
author:NotWearingPants
feat(Topology/Connected/LocPathConnected): instance for `LocPathConnected` + `ConnectedSpace` → `PathConnectedSpace` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) awaiting-bench new-contributor t-topology 4/2 Mathlib/Topology/Connected/LocPathConnected.lean 1 7 ['NotWearingPants', 'github-actions', 'j-loreaux', 'leanprover-bot', 'leanprover-community-mathlib4-bot'] nobody
1-50496
1 day ago
1-50496
1 day ago
1-54114
1 day
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 71/0 Mathlib.lean,Mathlib/RingTheory/PowerSeries/Catalan.lean 2 4 ['Ruben-VandeVelde', 'github-actions', 'wwylele'] kbuzzard
assignee:kbuzzard
1-39099
1 day ago
34-35174
1 month ago
34-35204
34 days
28546 Sfgangloff
author:Sfgangloff
feat(SymbolicDynamics): basic setup of Zd, full shift, cylinders, pat… # Symbolic dynamics on groups: core API and entropy along finite shapes This PR adds a **group-generic** foundation for symbolic dynamics over an arbitrary group `G`, together with convenient specializations for `ℤ` and `ℤ^d`. ## Summary of additions - **Full shift and shift action** - `abbrev FullShift (A G) := G → A` (inherits product topology from the Π-type). - Right shift `shift g x` with convention `(shift g x) h = x (h * g)`. - **Cylinders and topology** - `cylinder U x : Set (G → A)` for finite `U : Finset G`. - Cylinders are open under `[DiscreteTopology A]`; with a finite alphabet they are also closed. - Equality with dependent products: `cylinder U x = Set.pi (↑U) (fun i => ({x i} : Set A))`, enabling use of the `Set.pi` API. - **Patterns, occurrences, and subshifts** - `Pattern A G` with finite `support : Finset G` and `data : support → A`. - `Pattern.occursIn p x g` (occurrence at translate `g`) and the expected shift law. - `forbids F` and `Subshift A G` (closed, shift-invariant subsets). - `FixedSupport A G U` with an equivalence to `(U → A)` to obtain finiteness. - **Language on finite shapes and counting** - `languageOn X U`, `languageCardOn X U`, and `patternCountOn Y U`. - **Entropy along a shape sequence** - `limsupAtTop` (as an `sInf` of eventual upper bounds). - `entropyAlong X F hF := limsup (log (patternCountOn X (F n) + 1) / |F n|)` for any nonempty finite shapes `F : ℕ → Finset G` (the `+ 1` avoids `log 0`). - **Specializations** - `IntShapes`: segments `[-n,n]` on `Multiplicative ℤ`, with `entropy_Z`. - `ZdShapes`: boxes `[-n,n]^d` on `ℤ^d` (as functions `Fin d → ℤ`), with `entropy_Zd`. ## Mathematical remarks - The API is **shape-parametric**: entropy is defined along user-provided finite shapes. - On **amenable** groups, using a **Følner** sequence yields a canonical value (Ornstein–Weiss). This PR does not assume amenability; the family of shapes is an explicit input. ## Motivation Provide a clean, reusable base for symbolic dynamics on groups in mathlib. ## Future work - Add a Følner predicate and prove shape-independence / limit existence on amenable groups. - Expand the `ℤ`/`ℤ^d` toolkit (alternative shapes, mixing, factors). - Develop 1D theory and, longer-term, multidimensional SFT results (e.g. along the lines of Hochman–Meyerovitch). new-contributor t-dynamics 747/0 Mathlib.lean,Mathlib/Dynamics/SymbolicDynamics/Basic.lean 2 80 ['Sfgangloff', 'eric-wieser', 'github-actions', 'kckennylau', 'sgouezel'] sgouezel
assignee:sgouezel
1-31597
1 day ago
1-31598
1 day ago
38-50465
38 days
30316 NotWearingPants
author:NotWearingPants
feat(Topology/Connected): locally (path-)connected compact spaces have finitely many (path-)connected components feat(Topology/Connected): locally (path-)connected compact spaces have finitely many (path-)connected components Locally (path-)connectedness implies all (path-)connected components are open, so they form an open cover. Compactness implies there's a finite subcover. Since the components are disjoint, the subcover must equal the cover. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) large-import new-contributor t-topology 41/0 Mathlib/Topology/Connected/Clopen.lean,Mathlib/Topology/Connected/LocPathConnected.lean,Mathlib/Topology/Connected/LocallyConnected.lean,Mathlib/Topology/Connected/PathConnected.lean 4 4 ['NotWearingPants', 'github-actions', 'j-loreaux'] nobody
0-76249
21 hours ago
0-76275
21 hours ago
1-703
1 day
30317 NotWearingPants
author:NotWearingPants
feat(Combinatorics/SimpleGraph/Acyclic): homomorphisms into an acyclic graph implies acyclic --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-combinatorics 43/4 Mathlib/Combinatorics/SimpleGraph/Acyclic.lean 1 3 ['NotWearingPants', 'github-actions', 'vlad902'] nobody
0-75817
21 hours ago
1-53771
1 day ago
1-53804
1 day
30344 Deep0Thinking
author:Deep0Thinking
feat(MeasureTheory/IntervalIntegral): 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 226/0 Mathlib.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral/MeanValue.lean 2 4 ['github-actions', 'plp127'] nobody
0-66596
18 hours ago
0-79855
22 hours ago
0-79888
22 hours
30354 NotWearingPants
author:NotWearingPants
feat(Combinatorics/SimpleGraph/Connectivity/WalkCounting): a spanning subgraph has the same or more connected components --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-combinatorics 8/0 Mathlib/Combinatorics/SimpleGraph/Connectivity/Connected.lean,Mathlib/Combinatorics/SimpleGraph/Connectivity/WalkCounting.lean 2 1 ['github-actions'] nobody
0-65512
18 hours ago
0-65525
18 hours ago
0-65559
18 hours
29960 yonggyuchoimath
author:yonggyuchoimath
feat(Algebra/Category/Ring): equalizers of pushout maps of tensor product inclusions This PR defines a ring map `S →ₗ[R] S ⊗[R] S : s ↦ (s ⊗ₜ[R] 1) - (1 ⊗ₜ[R] s)` for an `R`-algebra `S`, and show that its kernel is exactly (the image of) `R` if `S` is faithfully flat over `R`. Changes: * `TensorProduct.AlgebraTensorModule.distribBaseChange`: Origianlly takes `M` and `N`, where `M` is an `R`-module with an additional instance `IsScalarTower R A M`. This is unnecessary, so I changed the `M` and `N` into `N` and `Q`, now both of which are merely modules over `R`. Main results : * Add compatibility of `Algebra.TensorProduct.includeLeft` (or `Algebra.TensorProduct.includeRight`) with `TensorProduct.AlgebraTensorModule.distribBaseChange` and `LinearMap.lTensor` * Define `Algebra.TensorProduct.includeLeftSubRight`, which is the `R`-linear map `S →ₗ[R] S ⊗[R] S` sending `s : S` to `(s ⊗ₜ[R] 1) - (1 ⊗ₜ[R] s)`. * `Algebra.TensorProduct.exactIncludeLeftSubRight_of_faithfullyFlat`: the pair `algebraMap : R → S` and `includeLeftSubRight R S : S → S ⊗[R] S` is exact if `S` is a faithfully flat `R`-algebra. new-contributor 229/1 Mathlib.lean,Mathlib/LinearAlgebra/TensorProduct/Tower.lean,Mathlib/RingTheory/TensorProduct/Basic.lean,Mathlib/RingTheory/TensorProduct/IncludeLeftSubRight.lean 4 3 ['erdOne', 'github-actions', 'yonggyuchoimath'] TwoFX
assignee:TwoFX
0-62498
17 hours ago
8-82782
8 days ago
11-30852
11 days
30231 NotWearingPants
author:NotWearingPants
feat(LinearAlgebra/Matrix/Charpoly): `trace_eq_neg_charpoly_coeff` using `nextCoeff` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-algebra easy
label:t-algebra$
6/3 Mathlib/LinearAlgebra/Matrix/Charpoly/Coeff.lean,Mathlib/LinearAlgebra/Matrix/Charpoly/Eigs.lean 2 3 ['NotWearingPants', 'github-actions', 'mathlib4-merge-conflict-bot'] nobody
0-60031
16 hours ago
0-60053
16 hours ago
4-40890
4 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
label:t-algebra$
94/0 Mathlib/LinearAlgebra/Matrix/Transvection.lean,MathlibTest/matrix.lean 2 2 ['github-actions', 'riccardobrasca', 'zach1502'] riccardobrasca
assignee:riccardobrasca
0-34363
9 hours ago
16-78784
16 days ago
17-57848
17 days
30333 paulorauber
author:paulorauber
feat(Probability): definition of trajMeasure A definition of `trajMeasure` and some basic lemmas. In the context of the Ionescu-Tulcea theorem, `trajMeasure μ₀ κ` corresponds to the distribution of the trajectory obtained by starting with the distribution `μ₀` and then iterating the kernels `κ`. Lemmas `partialTraj_compProd_kernel_eq_traj_map` and `traj_map_eq_kernel` are attributable to @EtienneC30 and some definitions borrow code from @RemyDegenne , who also improved the code considerably. Please let me know if you would like to be co-authors in this pull request. From the LeanBandits project. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-measure-probability 78/1 Mathlib/Probability/Kernel/IonescuTulcea/Traj.lean 1 1 ['github-actions'] EtienneC30
assignee:EtienneC30
0-31071
8 hours ago
0-31071
8 hours ago
1-10401
1 day
29925 jcreinhold
author:jcreinhold
feat(CategoryTheory/MarkovCategory): Add Markov category This PR introduces Markov categories, extending copy-discard categories with natural discard to model categorical probability theory. This PR builds on #29939 and #29919 and was split up from #29657. ## Main additions ### 1. Markov categories (`MarkovCategory`) Extends `CopyDiscardCategory` where discard is natural: `f ≫ ε[Y] = ε[X]` for all morphisms `f : X → Y`. This forces a probabilistic interpretation where morphisms preserve normalization (probability measures sum to 1). ## Mathematical significance Markov categories capture probability theory categorically: - Morphisms: Stochastic processes/Markov kernels - Copy: Perfect correlation (both outputs always equal) - Discard: Marginalization (integrating out variables) - Natural discard: Preservation of total probability The same framework handles finite probability (stochastic matrices), measure-theoretic probability (Markov kernels), and quantum probability (completely positive maps). ## Design decisions - Terminal unit follows from axioms. We prove `unit_terminal` and `unit_isTerminal` rather than assuming them ## Implementation notes - Built on top of `CopyDiscardCategory` per suggestion [#mathlib4 > Markov categories PR @ 💬](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Markov.20categories.20PR/near/539656225) - Includes both computational (`unit_terminal`) and categorical (`unit_isTerminal`) characterizations of the terminal object ## References Cho & Jacobs (2019) and Fritz (2020) [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) - [x] depends on: #29939 new-contributor t-category-theory 171/0 Mathlib.lean,Mathlib/CategoryTheory/MarkovCategory/Basic.lean,MathlibTest/CategoryTheory/MarkovCategory.lean 3 7 ['github-actions', 'jcreinhold', 'joelriou', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot'] nobody
0-30150
8 hours ago
0-33132
9 hours ago
2-8180
2 days
29713 jessealama
author:jessealama
feat (Algebra/Homology): add Euler–Poincaré formula This PR adds the Euler characteristic for chain complexes and proves the Euler-Poincaré formula relating the alternating sum of chain dimensions to the alternating sum of homology dimensions. ### Main definitions (in `EulerCharacteristic.lean`) * `ChainComplex.boundedEulerChar`: The Euler characteristic over a finite set * `ChainComplex.eulerChar`: The Euler characteristic as an infinite sum * `ChainComplex.homologyBoundedEulerChar`: The homological Euler characteristic over a finite set * `ChainComplex.homologyEulerChar`: The homological Euler characteristic as an infinite sum Both bounded and infinite definitions work with ℤ-indexed complexes over any ring R. The file also includes theorems relating the formally infinite sums to finite sums when there is finite support: * `ChainComplex.eulerChar_eq_boundedEulerChar`: The infinite Euler characteristic equals the bounded one when the chain complex vanishes outside a finite set * `ChainComplex.homologyEulerChar_eq_homologyBoundedEulerChar`: The infinite homological Euler characteristic equals the bounded one when homology vanishes outside a finite set ### Main result (in `EulerPoincare.lean`) * `ChainComplex.eulerChar_eq_homology_eulerChar`: For ℤ-indexed bounded chain complexes of finite-dimensional modules over a division ring, the alternating sum of chain dimensions equals the alternating sum of homology dimensions. --- Related to: #29639, #29643, #29646 new-contributor t-algebra
label:t-algebra$
444/0 Mathlib.lean,Mathlib/Algebra/Homology/EulerCharacteristic.lean,Mathlib/Algebra/Homology/EulerPoincare.lean 3 19 ['github-actions', 'jessealama', 'joelriou', 'kim-em'] dagurtomas
assignee:dagurtomas
0-8074
2 hours ago
22-14894
22 days ago
23-24744
23 days

PRs on the review queue labelled 'easy'

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
28141 YaelDillies
author:YaelDillies
chore: deprecate `BialgHom.coe_toLinearMap` `BialgHom.toLinearMap` is a fake projection. From Toric --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory toric easy 5/11 Mathlib/RingTheory/Bialgebra/Hom.lean 1 8 ['YaelDillies', 'eric-wieser', 'github-actions'] alreadydone
assignee:alreadydone
53-62480
1 month ago
61-39609
2 months ago
61-39600
61 days
27567 themathqueen
author:themathqueen
feat(LinearAlgebra/TensorProduct/Associator): add `lid` and `assoc` tensor lemmas This adds `TensorProduct.lid_tensor` and `TensorProduct.assoc_tensor`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra easy
label:t-algebra$
31/2 Mathlib/LinearAlgebra/TensorProduct/Associator.lean,Mathlib/LinearAlgebra/TensorProduct/Basic.lean 2 3 ['github-actions', 'themathqueen'] mattrobball
assignee:mattrobball
30-8154
1 month ago
59-84077
1 month ago
73-76906
73 days
29626 themathqueen
author:themathqueen
chore(Algebra/Order/Module/PositiveLinearMap): generalize `OrderHomClass.ofLinear` Generalize `OrderHomClass.ofLinear` from linear maps to additive group homomorphisms. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-algebra easy
label:t-algebra$
10/11 Mathlib/Algebra/Order/Module/PositiveLinearMap.lean,Mathlib/Analysis/CStarAlgebra/CompletelyPositiveMap.lean 2 5 ['Ruben-VandeVelde', 'github-actions', 'themathqueen'] Vierkantor
assignee:Vierkantor
16-62500
16 days ago
24-15659
24 days ago
25-80412
25 days
30206 NotWearingPants
author:NotWearingPants
feat(Combinators/SimpleGraph/Hamiltonian): `p.support.length = Fintype.card α` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-combinatorics easy 8/0 Mathlib/Combinatorics/SimpleGraph/Hamiltonian.lean 1 2 ['NotWearingPants', 'github-actions'] nobody
4-86343
4 days ago
4-86354
4 days ago
4-86396
4 days
30215 NotWearingPants
author:NotWearingPants
feat(Data/List/NodupEquivFin): add equiv with `count = 1` hypothesis --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data new-contributor easy 7/2 Mathlib/Data/List/NodupEquivFin.lean 1 2 ['NotWearingPants', 'github-actions'] nobody
4-73164
4 days ago
4-73164
4 days ago
4-73549
4 days
30214 NotWearingPants
author:NotWearingPants
feat(Data/List/Basic): add `Fin` variants of `*mem_iff_getElem` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data new-contributor easy 11/0 Mathlib/Data/List/Basic.lean 1 2 ['NotWearingPants', 'github-actions'] nobody
4-73093
4 days ago
4-73093
4 days ago
4-73846
4 days
30213 NotWearingPants
author:NotWearingPants
feat(Data/List/GetD): golf and add lemmas for `get` and `getElem?.get` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data new-contributor easy 18/16 Mathlib/Data/List/GetD.lean 1 8 ['NotWearingPants', 'github-actions', 'themathqueen'] nobody
4-66231
4 days ago
4-75372
4 days ago
4-75570
4 days
30232 NotWearingPants
author:NotWearingPants
feat(Combinatorics/SimpleGraph/Connectivity/Subgraph): add `ConnectedComponent.toSubgraph` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-combinatorics easy 17/0 Mathlib/Combinatorics/SimpleGraph/Connectivity/Subgraph.lean 1 2 ['NotWearingPants', 'github-actions'] nobody
4-40494
4 days ago
4-54177
4 days ago
4-54217
4 days
30264 pechersky
author:pechersky
feat(RingTheory/RootsOfUnity): `rootsOfUnity_inf_rootsOfUnity` towards torsion subgroup as union of roots of unity of prime powers --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-ring-theory easy 12/0 Mathlib/RingTheory/RootsOfUnity/Basic.lean 1 1 ['github-actions'] nobody
3-18487
3 days ago
3-58395
3 days ago
3-58436
3 days
30216 NotWearingPants
author:NotWearingPants
feat(Data/List/Basic): `get` is surjective iff every element is in the list --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data new-contributor easy 13/0 Mathlib/Data/List/Basic.lean 1 6 ['NotWearingPants', 'github-actions', 'themathqueen'] nobody
2-12181
2 days ago
4-73157
4 days ago
4-73192
4 days
30219 NotWearingPants
author:NotWearingPants
feat(Combinatorics/SimpleGraph/Paths): path iff `p.support.get` is injective --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-combinatorics easy 4/0 Mathlib/Combinatorics/SimpleGraph/Paths.lean 1 3 ['NotWearingPants', 'github-actions', 'themathqueen'] nobody
2-11408
2 days ago
4-70220
4 days ago
4-70254
4 days
30205 NotWearingPants
author:NotWearingPants
feat(Combinatorics/SimpleGraph/Walk): `p.getVert` is `p.support.get` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) maintainer-merge new-contributor t-combinatorics easy 10/0 Mathlib/Combinatorics/SimpleGraph/Walk.lean 1 5 ['NotWearingPants', 'Ruben-VandeVelde', 'github-actions', 'themathqueen'] nobody
1-79227
1 day ago
4-29145
4 days ago
5-294
5 days
30220 NotWearingPants
author:NotWearingPants
chore(Data/List/Nodup): golf `nodup_iff_injective_get` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data new-contributor easy 2/5 Mathlib/Data/List/Nodup.lean 1 4 ['NotWearingPants', 'euprunin', 'github-actions'] nobody
1-78573
1 day ago
4-68618
4 days ago
4-68655
4 days
28488 euprunin
author:euprunin
chore(SetTheory): deprecate `mk_multiset_of_countable` and `iSup_succ`. remove `cast_succ`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-set-theory easy 3/13 Mathlib/SetTheory/Cardinal/Basic.lean,Mathlib/SetTheory/Cardinal/Finsupp.lean,Mathlib/SetTheory/Ordinal/Family.lean,Mathlib/SetTheory/Ordinal/NaturalOps.lean 4 13 ['euprunin', 'github-actions', 'mathlib4-merge-conflict-bot', 'vihdzp'] nobody
1-74210
1 day ago
1-74210
1 day ago
16-24548
16 days
28818 NotWearingPants
author:NotWearingPants
feat(Data/Setoid/Basic): add theorems about lifting a function to its kernel Currently `ker_lift_injective` and `quotientKerEquivOfRightInverse` lift `f` to `ker f` in their definition. This PR makes this function available as `Setoid.ker_lift f` and adds a few more theorems about it. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-data new-contributor easy 29/15 Counterexamples/AharoniKorman.lean,Mathlib/Data/Setoid/Basic.lean,Mathlib/NumberTheory/NumberField/CanonicalEmbedding/FundamentalCone.lean,Mathlib/Topology/Separation/Hausdorff.lean 4 18 ['NotWearingPants', 'eric-wieser', 'github-actions', 'kckennylau', 'mathlib4-merge-conflict-bot'] pechersky
assignee:pechersky
1-62506
1 day ago
26-85996
26 days ago
45-14535
45 days
28497 euprunin
author:euprunin
chore(RingTheory/LocalRing/ResidueField): deprecate`isLocalHom_residue` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) easy 3/8 Mathlib/RingTheory/LocalRing/ResidueField/Basic.lean,Mathlib/RingTheory/Valuation/ValuationSubring.lean 2 5 ['Ruben-VandeVelde', 'euprunin', 'github-actions', 'mathlib4-merge-conflict-bot'] nobody
1-38374
1 day ago
1-74187
1 day ago
5-6693
5 days
30062 plp127
author:plp127
chore(Order/Defs/PartialOrder): golf non-instance Golf `decidableLTOfDecidableLE` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) t-order easy 2/6 Mathlib/Order/Defs/PartialOrder.lean 1 1 ['Bergschaf', 'github-actions'] nobody
1-37211
1 day ago
10-70707
10 days ago
10-70696
10 days
30231 NotWearingPants
author:NotWearingPants
feat(LinearAlgebra/Matrix/Charpoly): `trace_eq_neg_charpoly_coeff` using `nextCoeff` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) new-contributor t-algebra easy
label:t-algebra$
6/3 Mathlib/LinearAlgebra/Matrix/Charpoly/Coeff.lean,Mathlib/LinearAlgebra/Matrix/Charpoly/Eigs.lean 2 3 ['NotWearingPants', 'github-actions', 'mathlib4-merge-conflict-bot'] nobody
0-60031
16 hours ago
0-60053
16 hours ago
4-40890
4 days
30353 JovanGerb
author:JovanGerb
chore(Topology/ContinuousMap/CompactlySupported): golf `exists_add_nnrealPart_add_eq` This PR shortens the proof of `exists_add_nnrealPart_add_eq`, based on #29866 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) maintainer-merge t-topology easy 3/38 Mathlib/Topology/ContinuousMap/CompactlySupported.lean 1 2 ['github-actions', 'grunweg'] nobody
0-13781
3 hours ago
0-13781
3 hours ago
0-68553
19 hours
30306 joelriou
author:joelriou
chore(CategoryTheory/Presentable/IsCardinalFiltered): fix name The wrong name `isFiltered_of_isCardinalDirected` is fixed: the correct name is `isFiltered_of_isCardinalFiltered`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) maintainer-merge t-category-theory easy 13/10 Mathlib/CategoryTheory/Abelian/GrothendieckCategory/ColimCoyoneda.lean,Mathlib/CategoryTheory/Abelian/GrothendieckCategory/Subobject.lean,Mathlib/CategoryTheory/Presentable/IsCardinalFiltered.lean,Mathlib/CategoryTheory/Presentable/Limits.lean 4 2 ['github-actions', 'grunweg'] nobody
0-13700
3 hours ago
0-13700
3 hours ago
2-3150
2 days
30249 vihdzp
author:vihdzp
feat: `IsRoot.mul_div_eq` --- I found myself reaching for this the other day, figured I might as well add it. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) maintainer-merge t-algebra easy
label:t-algebra$
3/1 Mathlib/Algebra/Polynomial/FieldDivision.lean,Mathlib/RingTheory/AdjoinRoot.lean 2 2 ['github-actions', 'grunweg'] nobody
0-13117
3 hours ago
0-13117
3 hours ago
3-85835
3 days
30358 smmercuri
author:smmercuri
style: fix capitalisation `Valued.isOpen_closedball -> Valued.isOpen_closedBall` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) maintainer-merge t-topology easy 7/4 Mathlib/Topology/Algebra/Valued/LocallyCompact.lean,Mathlib/Topology/Algebra/Valued/ValuationTopology.lean 2 4 ['github-actions', 'grunweg'] nobody
0-6529
1 hour ago
0-6529
1 hour ago
0-30785
8 hours
30377 ocfnash
author:ocfnash
chore: drastically speed up `LieModule.Cohomology.d₂₃` Co-authored-by: Anne C.A. Baanen --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) maintainer-merge t-algebra easy
label:t-algebra$
15/23 Mathlib/Algebra/Lie/Cochain.lean 1 8 ['github-actions', 'grunweg', 'leanprover-bot', 'ocfnash', 'sgouezel'] nobody
0-2229
37 minutes ago
0-6294
1 hour ago
0-11101
3 hours

PRs on the review queue labelled 'tech debt' or 'longest-pole'

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
30107 grunweg
author:grunweg
chore: track occurrences of 'nonrec' as technical debt Matches leanprover-community/leanprover-community.github.io#689: only merge when that is deemed a good idea. -------- TODO: make the count more robust, for instance count all occurrences of "^nonrec " plus those of "^[private|protected] nonrec ". --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) tech debt CI 1/0 scripts/technical-debt-metrics.sh 1 1 ['github-actions'] robertylewis
assignee:robertylewis
0-62493
17 hours ago
8-35381
8 days ago
8-35360
8 days