Helping out: short tasks

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

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

This dashboard was last updated on: November 14, 2025 at 06:51 UTC

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

There are currently no PRs with just an infrastructure-related CI failure. Congratulations!

PRs looking for help

Number	Author	Title	Description	Labels	+/-	Modified files (first 100)	📝	💬	All users who commented or reviewed	Assignee(s)	Updated	Last status change	total time in review
6859	MohanadAhmed author:MohanadAhmed	TryLean4Bundle: Windows Bundle Creator	# `TryLean4Bundle`: Windows Bundle Creator A Windows batch script and a CI yml file that create an self extracting archive. The user should 1. just download the archive, 2. double click the archive to expand 3. double click the `RunLean.bat` script in the expanded archive. The script currently downloads 7 dependencies into CI then unpacks them in the appropriate locations and finally packs them back. To try a bundle created using these scripts but from a different repo see (https://github.com/MohanadAhmed/TryLean4Bundle/releases) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	CI WIP help-wanted	114/0	.github/workflows/mk_windows_bundle.yml,scripts/windowsBundle.bat	2	0	[]	nobody	470-81464 1 year ago	807-24335 2 years ago	0-0 0 seconds
13442	dignissimus author:dignissimus	feat: mabel tactic for multiplicative abelian groups	Mabel tactic for multiplicative abelian groups (#10361) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-meta modifies-tactic-syntax awaiting-author help-wanted	439/0	Mathlib.lean,Mathlib/Tactic.lean,Mathlib/Tactic/MAbel.lean,MathlibTest/mabel.lean	4	10	['BoltonBailey', 'dignissimus', 'github-actions', 'joneugster', 'kbuzzard']	joneugster assignee:joneugster	267-29665 8 months ago	272-11261 8 months ago	0-16 16 seconds
5919	MithicSpirit author:MithicSpirit	feat: implement orthogonality for AffineSubspace	Define `AffineSubspace.orthogonal` and `AffineSubspace.IsOrtho`, as well as develop an API emulating that of `Submodule.orthogonal` and `Submodule.IsOrtho`, respectively. Additionally, provide some relevant lemmas exclusive to affine subspaces, which are mostly to do with the relationship between orthogonality and `AffineSubspace.Parallel`. Closes #5539 --- Still WIP as I need to add more docstrings as well as notations for the new definitions. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-analysis WIP help-wanted	287/0	Mathlib.lean,Mathlib/Analysis/InnerProductSpace/AffineSubspace.lean	2	6	['MithicSpirit', 'eric-wieser', 'github-actions', 'leanprover-community-bot-assistant']	MithicSpirit assignee:MithicSpirit	180-45888 5 months ago	180-45906 5 months ago	0-0 0 seconds
22925	ggranberry author:ggranberry	feat(Mathlib/PlaceHolder/ToeplitzHausdorff): Toeplitz-Hausdorff	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	will-close-soon new-contributor t-analysis awaiting-author WIP help-wanted	411/0	Mathlib/PlaceHolder/ToeplitzHausdorff.lean,Mathlib/PlaceHolder/ToeplitzHausdorff_v2.lean	2	11	['faenuccio', 'ggranberry', 'github-actions']	faenuccio assignee:faenuccio	92-71513 3 months ago	92-71716 3 months ago	4-24257 4 days
26349	mans0954 author:mans0954	feat(Analysis/SpecialFunctions/Trigonometric/Basic): sin and cos of multiples of π / 3	This PR continues the work from #25009. Original PR: https://github.com/leanprover-community/mathlib4/pull/25009	t-analysis help-wanted	159/0	Mathlib/Algebra/Order/Monoid/NatCast.lean,Mathlib/Analysis/SpecialFunctions/Trigonometric/Basic.lean,Mathlib/Data/Nat/Cast/Defs.lean,MathlibTest/trigonometry.lean	4	3	['github-actions', 'mans0954', 'themathqueen']	nobody	88-37140 2 months ago	101-74425 3 months ago	5-42837 5 days
29675	yury-harmonic author:yury-harmonic	feat(Wolstenholme): new file	Co-authored-by: @Aristotle-Harmonic --- I still need to cleanup the proof and write the docs. For now, it's just what the AI generated, forward-ported to the latest Mathlib. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data awaiting-author help-wanted	198/0	Mathlib.lean,Mathlib/Data/Nat/Choose/Wolstenholme.lean	2	3	['github-actions', 'yury-harmonic']	nobody	59-44480 1 month ago	59-44480 1 month ago	0-125 2 minutes
29634	YaelDillies author:YaelDillies	feat: missing instance `NonUnitalCommSemiring R → NonUnitalNonAssocCommSemiring R`	For some reason, this causes elaboration issues. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra awaiting-CI help-wanted label:t-algebra$	16/7	Mathlib/Algebra/Ring/Defs.lean,Mathlib/RingTheory/Coalgebra/Basic.lean,Mathlib/RingTheory/Coalgebra/Hom.lean,Mathlib/Tactic/Ring/Basic.lean	4	7	['YaelDillies', 'alreadydone', 'github-actions', 'riccardobrasca']	nobody	27-53819 27 days ago	60-76036 1 month ago	0-19 19 seconds
12934	grunweg author:grunweg	chore: replace more uses of > or ≥ by < or ≤	These were flagged by the linter in https://github.com/leanprover-community/mathlib4/pull/12879: it is easy to simple avoid > or ≥ in hypotheses or haves. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict awaiting-author help-wanted	41/42	Archive/Imo/Imo1962Q1.lean,Archive/Imo/Imo1988Q6.lean,Archive/Imo/Imo1994Q1.lean,Archive/Imo/Imo2005Q3.lean,Archive/Imo/Imo2006Q3.lean,Archive/Imo/Imo2008Q2.lean,Archive/Imo/Imo2008Q3.lean,Archive/Imo/Imo2019Q4.lean,Archive/Sensitivity.lean,Archive/Wiedijk100Theorems/CubingACube.lean,Mathlib/Tactic/Linarith/Datatypes.lean,test/cancel_denoms.lean,test/congr.lean,test/interval_cases.lean,test/observe.lean	15	11	['YaelDillies', 'adomani', 'github-actions', 'grunweg', 'jcommelin', 'urkud']	nobody	470-81468 1 year ago	484-4665 1 year ago	1-73101 1 day
9642	eric-wieser author:eric-wieser	refactor(Analysis/Normed/{Group/Field}/Basic): Let `extends` generate the repeated fields	New-style structure shenanigans mean that instance constructors randomly complain about a missing field that can be found with `__ : MetricSpace _ := infer_instance`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) I will write a longer PR description for this once CI is happy	t-analysis merge-conflict awaiting-author WIP help-wanted	122/202	Mathlib/Analysis/Calculus/ContDiff/Basic.lean,Mathlib/Analysis/Complex/Basic.lean,Mathlib/Analysis/Matrix.lean,Mathlib/Analysis/Normed/Field/Basic.lean,Mathlib/Analysis/Normed/Group/Basic.lean,Mathlib/Analysis/Normed/Group/Completion.lean,Mathlib/Analysis/Normed/Order/Basic.lean,Mathlib/Analysis/NormedSpace/ProdLp.lean,Mathlib/Analysis/NormedSpace/Star/Matrix.lean,Mathlib/Analysis/NormedSpace/Unitization.lean,Mathlib/Analysis/Quaternion.lean,Mathlib/Geometry/Manifold/Instances/Sphere.lean,Mathlib/InformationTheory/Hamming.lean,Mathlib/MeasureTheory/Measure/Lebesgue/VolumeOfBalls.lean,Mathlib/NumberTheory/NumberField/CanonicalEmbedding.lean,Mathlib/NumberTheory/Padics/PadicIntegers.lean,Mathlib/Topology/ContinuousFunction/Bounded.lean	17	11	['eric-wieser', 'leanprover-bot', 'urkud']	nobody	470-81465 1 year ago	648-61367 1 year ago	0-0 0 seconds
6931	urkud author:urkud	refactor(Analysis/Normed): use `RingHomIsometric` for `.norm_cast`	--- I don't understand why linter fails. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-analysis merge-conflict help-wanted	78/68	Mathlib/Analysis/LocallyConvex/ContinuousOfBounded.lean,Mathlib/Analysis/Normed/Field/Basic.lean,Mathlib/Analysis/Normed/Group/Basic.lean,Mathlib/Analysis/NormedSpace/Basic.lean,Mathlib/Analysis/NormedSpace/Exponential.lean,Mathlib/Analysis/NormedSpace/Spectrum.lean,Mathlib/Analysis/RCLike/Basic.lean,Mathlib/NumberTheory/NumberField/Embeddings.lean	8	0	[]	nobody	470-81464 1 year ago	492-62168 1 year ago	0-0 0 seconds
6791	eric-wieser author:eric-wieser	refactor: Use flat structures for morphisms	This restores the symmetry we had in Lean3, where we had `MonoidHom.mk f one mul` not `MonoidHom.mk (OneHom.mk f one) mul`, and `f.toFun` wasn't notation for `f.toMulHom.toFun`. The nesting provided by the previous inheritance is useless to us in the face of `MonoidHomClass.toMonoidHom`, which completely eta-expands the structure anyway. We call the class `FunLikeFlatHack._` because this means the field is called `to_` which uses up less space in the goal view than any alternative. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-CI merge-conflict awaiting-author help-wanted	174/201	Mathlib/Algebra/Algebra/Equiv.lean,Mathlib/Algebra/Algebra/Hom.lean,Mathlib/Algebra/Category/GroupCat/ZModuleEquivalence.lean,Mathlib/Algebra/Category/GroupWithZeroCat.lean,Mathlib/Algebra/Category/ModuleCat/Presheaf.lean,Mathlib/Algebra/Category/MonCat/Basic.lean,Mathlib/Algebra/Group/Ext.lean,Mathlib/Algebra/Group/Prod.lean,Mathlib/Algebra/Group/UniqueProds.lean,Mathlib/Algebra/Hom/Equiv/Basic.lean,Mathlib/Algebra/Hom/Group/Defs.lean,Mathlib/Algebra/Hom/GroupAction.lean,Mathlib/Algebra/Hom/NonUnitalAlg.lean,Mathlib/Algebra/Hom/Ring/Defs.lean,Mathlib/Algebra/Lie/Basic.lean,Mathlib/Algebra/Module/Equiv.lean,Mathlib/Algebra/Module/LinearMap.lean,Mathlib/Algebra/Order/Hom/Ring.lean,Mathlib/Algebra/Order/Interval.lean,Mathlib/Algebra/Ring/Equiv.lean,Mathlib/Analysis/Normed/Group/SemiNormedGroupCat.lean,Mathlib/Data/FunLike/Basic.lean,Mathlib/Data/Rat/Cast/CharZero.lean,Mathlib/Data/Real/EReal.lean,Mathlib/Data/Real/Sqrt.lean,Mathlib/GroupTheory/FreeAbelianGroup.lean,Mathlib/GroupTheory/MonoidLocalization.lean,Mathlib/LinearAlgebra/Quotient.lean,Mathlib/LinearAlgebra/TensorProduct.lean,Mathlib/RingTheory/RingInvo.lean,Mathlib/Topology/Algebra/Module/Basic.lean,Mathlib/Topology/MetricSpace/Dilation.lean	32	0	[]	nobody	470-81464 1 year ago	787-49324 2 years ago	0-0 0 seconds
5934	eric-wieser author:eric-wieser	feat: port Data.Rat.MetaDefs	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) This needs some eyes from people familiar with Qq	t-meta merge-conflict mathlib-port help-wanted	183/0	Mathlib.lean,Mathlib/Data/Rat/MetaDefs.lean,test/rat.lean	3	4	['eric-wieser', 'gebner']	nobody	470-81463 1 year ago	640-68452 1 year ago	0-0 0 seconds
7903	urkud author:urkud	feat: define `UnboundedSpace`	--- The new instances generate some timeouts, and I don't understand why. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology merge-conflict help-wanted	111/59	Mathlib/Analysis/BoxIntegral/Basic.lean,Mathlib/Analysis/Normed/Module/Basic.lean,Mathlib/Topology/Bornology/Basic.lean,Mathlib/Topology/Bornology/Constructions.lean,Mathlib/Topology/MetricSpace/Bounded.lean,Mathlib/Topology/MetricSpace/GromovHausdorffRealized.lean	6	1	['github-actions']	nobody	463-69441 1 year ago	463-69441 1 year ago	0-0 0 seconds
9444	erdOne author:erdOne	feat: Various instances regarding `𝓞 K`.	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-number-theory merge-conflict help-wanted	27/0	Mathlib/NumberTheory/NumberField/Basic.lean,Mathlib/RingTheory/IntegralClosure.lean	2	9	['erdOne', 'leanprover-bot', 'mattrobball', 'riccardobrasca', 'xroblot']	nobody	455-71217 1 year ago	455-71217 1 year ago	0-0 0 seconds
14739	urkud author:urkud	feat(Measure): add `gcongr` lemmas	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-measure-probability merge-conflict awaiting-author WIP help-wanted	12/8	Mathlib/MeasureTheory/Covering/Differentiation.lean,Mathlib/MeasureTheory/Function/SimpleFunc.lean,Mathlib/MeasureTheory/Integral/SetToL1.lean,Mathlib/MeasureTheory/Measure/MeasureSpace.lean,Mathlib/Probability/Kernel/Disintegration/Density.lean	5	3	['github-actions', 'kim-em', 'urkud']	nobody	362-79604 11 months ago	362-79604 11 months ago	0-66587 18 hours
11837	trivial1711 author:trivial1711	feat: completion of a uniform multiplicative group	Multiplicativize `Topology.Algebra.GroupCompletion`. That is, rewrite it in the multiplicative setting and recover the original results using `@[to_additive]`. - Because `@[to_additive]` doesn't work with `noncomputable section` (https://github.com/leanprover/lean4/pull/2610), some instances with `@[to_additive]` need to be explicitly marked with `noncomputable instance`. - One might be tempted to multiplicativize this definition from `Topology.Algebra.GroupCompletion`: ```lean instance [UniformSpace α] [Add α] : Add (Completion α) := ⟨Completion.map₂ (· + ·)⟩ ``` to this: ```lean @[to_additive] instance [UniformSpace α] [Mul α] : Mul (Completion α) := ⟨Completion.map₂ (· * ·)⟩ ``` However, as Eric Wieser pointed out, doing so would create a bad diamond with the definition ```lean instance [UniformSpace α] [TopologicalRing α] [UniformAddGroup α] [Ring α] : Mul (Completion α) := ⟨curry <\| (denseInducing_coe.prod denseInducing_coe).extend ((↑) ∘ uncurry (· * ·))⟩ ``` in `Topology.Algebra.UniformRing`. How should this diamond be resolved? Well, the definition of multiplication that uses `curry <\| (denseInducing_coe.prod denseInducing_coe).extend ((↑) ∘ uncurry (· * ·))` is the "correct" one. For example, it yields the correct result if `α` is `ℚ`, unlike the definition that uses `Completion.map₂ (· * ·)`. (This is because `Completion.map₂` yields junk values if used on a function which is not uniformly continuous. Note, however, that if multiplication on `α` is uniformly continuous, then `Completion.map₂ (· * ·)` and `curry <\| (denseInducing_coe.prod denseInducing_coe).extend ((↑) ∘ uncurry (· * ·))` are propositionally equal.) So, following Eric's suggestion, we remove the definition that uses `Completion.map₂ (· * ·)`, and generalize the other definition to any uniform space with a multiplication operation: ```lean @[to_additive] noncomputable instance [UniformSpace α] [Mul α] : Mul (Completion α) := ⟨curry <\| (denseInducing_coe.prod denseInducing_coe).extend ((↑) ∘ uncurry (· * ·))⟩ ``` This requires slightly modifying some of the proofs in `Topology.Algebra.GroupCompletion`. For example, suppose that `α` is a uniform group. Since we can no longer use `Completion.continuous_map₂`, it becomes more efficient to prove that the multiplication, inversion, and division operations on `Completion α` are uniformly continuous before we prove that `Completion α` is a group. - Previously, `Topology.Algebra.GroupCompletion` had an instance: ```lean instance [UniformSpace α] [Sub α] : Sub (Completion α) := ... ``` Naively multiplicativizing this would yield ```lean @[to_additive] instance [UniformSpace α] [Inv α] : Inv (Completion α) := ... ``` Unfortunately, this would conflict with `Topology.Algebra.UniformField`, which already instantiates `Inv (Completion α)` when `α` is a uniform field. Instead, we use two different `instance` declarations. (If `α` is an additive group, then this instantiates `Neg (Completion α)` twice, and the instances are syntactically equal.) ```lean @[to_additive] noncomputable instance [UniformSpace α] [Group α] : Inv (Completion α) := ... instance [UniformSpace α] [Neg α] : Neg (Completion α) := ... ``` This avoids the bad diamond (because a uniform field can never be a `Group`) while remaining backward compatible. Note that the `@[to_additive]` is necessary here, because it maintains the link between the additive setting and multiplicative setting. We use a similar method to instantiate `Div (Completion α)`. - Some definitions in this file involve a module structure on `α`. We leave these as is and do not attempt to multiplicativize them at all. - The instance of `DistribMulAction` must be multiplicativized to an instance of `MulDistribMulAction` manually. Zulip thread: https://leanprover.zulipchat.com/#narrow/stream/287929-mathlib4/topic/Completion.20of.20a.20uniform.20multiplicative.20group --- # (Small) Issue Recall the following trick that this pull request uses to define inversion and negation on uniform spaces. The idea is that we define negation on the completion of any uniform space that has a negation operation, but we define inversion on only the completion of a uniform space that has the structure of a multiplicative group. We do this to avoid creating a bad diamond with the inversion operation on a uniform field. ```lean @[to_additive] noncomputable instance {α : Type} [UniformSpace α] [Group α] : Inv (Completion α) := ... instance {α : Type} [UniformSpace α] [Neg α] : Neg (Completion α) := ... ``` Now, suppose that we want to prove `coe_inv_of_group` (resp. `coe_neg`), which states that the coercion `α → Completion α` commutes with inversion (resp. negation). In the current version of this pull request, `coe_inv_of_group` (resp. `coe_neg`) only applies to uniform multiplicative (resp. additive) groups. However, we do not use the fact that multiplication (resp. addition) on `α` is uniformly continuous to prove it. We only use the fact that inversion (resp. negation) is continuous. So, what we really want is to have more general statements that look like this: ```lean theorem coe_inv_of_group {α : Type} [UniformSpace α] [Group α] [ContinuousInv α] : ... theorem coe_neg {α : Type} [UniformSpace α] [Neg α] [ContinuousNeg α] : ... ``` Note that `coe_inv_of_group` needs the assumption `[Group α]`, because otherwise inversion is not defined on `Completion α` at all. However, `coe_neg` does not need the analogous assumption `[AdditiveGroup α]`. The question is: If `coe_inv_of_group` and `coe_neg` are written in this more general form, how can we link them using `@[to_additive]`? Here is one option, but it obviously leaves something to be desired. ```lean @[to_additive coe_neg_do_not_use_this_use_the_more_general_version] theorem coe_inv_of_group {α : Type} [UniformSpace α] [Group α] [ContinuousInv α] : ... theorem coe_neg {α : Type} [UniformSpace α] [Neg α] [ContinuousNeg α] : ... ``` Co-authored-by: Eric Wieser --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra t-topology merge-conflict WIP help-wanted label:t-algebra$	342/217	Mathlib/Analysis/InnerProductSpace/Completion.lean,Mathlib/Analysis/Normed/Group/HomCompletion.lean,Mathlib/Analysis/Normed/Module/Completion.lean,Mathlib/Topology/Algebra/GroupCompletion.lean,Mathlib/Topology/Algebra/InfiniteSum/GroupCompletion.lean,Mathlib/Topology/Algebra/Nonarchimedean/Completion.lean,Mathlib/Topology/Algebra/UniformField.lean,Mathlib/Topology/Algebra/UniformMulAction.lean,Mathlib/Topology/Algebra/UniformRing.lean	9	14	['eric-wieser', 'github-actions', 'trivial1711']	nobody	287-36662 9 months ago	287-36662 9 months ago	101-64856 101 days
15115	kkytola author:kkytola	feat: Generalize assumptions in liminf and limsup results in ENNReals	In a [review comment](https://github.com/leanprover-community/mathlib4/pull/13938#discussion_r1649744441) it was pointed out that results about liminf and limsup in ENNReal hold under milder assumptions. This PR does the generalization. --- This PR is split off from #13938, where the review comment was made. The changes needed for the suggested generalization were of different kind than the simple PR's content, justifying a separate PR. - [x] depends on: #13938 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-order t-topology merge-conflict awaiting-author help-wanted	215/27	Mathlib/MeasureTheory/Measure/Portmanteau.lean,Mathlib/Order/LiminfLimsup.lean,Mathlib/Topology/Instances/ENNReal.lean	3	8	['Ruben-VandeVelde', 'github-actions', 'grunweg', 'j-loreaux', 'kkytola', 'leanprover-community-mathlib4-bot']	nobody	182-64517 5 months ago	207-48821 6 months ago	21-25493 21 days
7300	ah1112 author:ah1112	feat: synthetic geometry	This is adding synthetic geometry using Avigad's axioms and formalizing Euclid Book I, through the Pythagorean theorem. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-euclidean-geometry merge-conflict awaiting-author help-wanted	2661/0	Mathlib.lean,Mathlib/Geometry/Synthetic/Avigad/Axioms.lean,Mathlib/Geometry/Synthetic/Avigad/EuclidBookI.lean,Mathlib/Geometry/Synthetic/Avigad/Tactics.lean	4	74	['ah1112', 'alreadydone', 'eric-wieser', 'github-actions', 'leanprover-community-bot-assistant', 'plp127', 'tb65536', 'urkud']	nobody	84-17878 2 months ago	113-52836 3 months ago	0-0 0 seconds
5863	eric-wieser author:eric-wieser	feat: add elaborators for concrete matrices	--- - [x] depends on: #5866 - [ ] depends on: #5897 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-meta blocked-by-other-PR help-wanted	257/7	Mathlib/Control/Monad/Cont.lean,Mathlib/Data/Matrix/Auto.lean,MathlibTest/matrix_auto.lean	3	7	['eric-wieser', 'github-actions', 'kim-em', 'leanprover-community-bot-assistant']	nobody	173-31667 5 months ago	173-31688 5 months ago	0-0 0 seconds

PRs with just a merge conflict

Number	Author	Title	Description	Labels	+/-	Modified files (first 100)	📝	💬	All users who commented or reviewed	Assignee(s)	Updated	Last status change	total time in review
12936	mattrobball author:mattrobball	chore(Quiver.Opposite): make `Quiver.Hom.op/unop` `abbrev`'s	These are wrappers around the constructor and projection for `Opposite Quiver.Hom _ _`. The projection itself is reducible and with structure eta built in to defeq it seems like we might be making Lean work harder than is necessary. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict	39/34	Mathlib/Algebra/Homology/ShortComplex/Homology.lean,Mathlib/Algebra/Homology/ShortComplex/RightHomology.lean,Mathlib/CategoryTheory/Idempotents/Basic.lean,Mathlib/CategoryTheory/Limits/HasLimits.lean,Mathlib/CategoryTheory/Limits/Opposites.lean,Mathlib/CategoryTheory/Opposites.lean,Mathlib/CategoryTheory/Sites/CoverLifting.lean,Mathlib/CategoryTheory/Subobject/Comma.lean,Mathlib/CategoryTheory/Triangulated/Opposite.lean,Mathlib/Combinatorics/Quiver/Basic.lean	10	9	['YaelDillies', 'kim-em', 'leanprover-bot', 'mattrobball']	nobody	470-81468 1 year ago	538-47460 1 year ago	0-0 0 seconds
8788	FMLJohn author:FMLJohn	feat(Algebra/Module/GradeZeroModule): if `A` is a graded semiring and `M` is a graded `A`-module, then each grade of `M` is a module over the 0-th grade of `A`.	--- - [ ] depends on: #8187 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	237/4	Mathlib.lean,Mathlib/Algebra/DirectSum/Internal.lean,Mathlib/Algebra/GradedMonoid.lean,Mathlib/Algebra/Module/GradeZeroModule.lean,Mathlib/RingTheory/GradedAlgebra/Basic.lean,Mathlib/RingTheory/GradedAlgebra/Noetherian.lean	6	4	['FMLJohn', 'github-actions', 'leanprover-community-mathlib4-bot']	nobody	470-81465 1 year ago	504-69367 1 year ago	0-0 0 seconds
6777	adomani author:adomani	chore(CovariantClass): replace eta-expanded (· ·), (· + ·), (· ≤ ·), (· < ·)	Replace `CovariantClass X X (· * ·) (· ≤ ·)` with -> `CovariantClass X X HMul.hMul LE.le` and similarly for `HAdd`, `LT`, `Contravariant`. This PR is inspired by [Issue #6646](https://github.com/leanprover-community/mathlib4/issues/6646) and, more specifically, [this comment](https://github.com/leanprover-community/mathlib4/issues/6646#issuecomment-1692792066). Note that https://github.com/leanprover/lean4/pull/2267 would make this unnecessary --- ```bash # First sed command: # the first captured pattern is `CovariantClass ` # the second captured pattern is `` # the third captured pattern is `+` or `` # the fourth captured pattern is `<` or `≤` # a match for `CovariantClass (· ·) (· ·)` becomes # `CovariantClass replaceop replaceop` # Second sed command: similar to the first, but looks for `(Function.swap (· ·))` sed -i ' s=$Co[ntra]variantClass \(..$ \2 \)(· $[+]$ ·) (· $[<≤]$ ·)=\1replaceop\3 replaceop\4=g s=$Co[ntra]variantClass \(..$ \2 \)($[Functio\.swap ]$(· $[+]$ ·)) (· $[<≤]$ ·)=\1(\3replaceop\4) replaceop\5=g s=replaceop+=HAdd.hAdd=g s=replaceop\=HMul.hMul=g s=replaceop<=LT.lt=g s=replaceop≤=LE.le=g s=$Co[ntra]variantClass N N$ (· \ ·) r=\1 HMul.hMul r=g s=$Co[ntra]variantClass N N (swap μ)$ (· ≤ ·)=\1 LE.le=g s=$Co[ntra]variantClass N N$ (swap (· \* ·)) r=\1 (swap HMul.hMul) r=g s=$CovariantClass (Filter α) (Filter α)$ (· / ·) (· ≤ ·)=\1 HDiv.hDiv LE.le=g s=$CovariantClass (Filter α) (Filter α)$ (swap (· / ·)) (· ≤ ·)=\1 (swap HDiv.hDiv) LE.le=g s=$Co[ntra]variantClass . (fun x y .> . \* .)$ (· ≤ ·)=\1 LE.le=g s=$Co[ntra]variantClass . (fun x y .> . \* .)$ (· < ·)=\1 LT.lt=g s=$Co[ntra]variantClass [^}]$ (· ≤ ·)=\1 LE.le=g s=$CovariantClass .* (Filter β)$ (· • ·) LE.le=\1 HSMul.hSMul LE.le=g ' $(git ls-files '*.lean') ``` [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict	703/678	Counterexamples/ZeroDivisorsInAddMonoidAlgebras.lean,Mathlib/Algebra/BigOperators/Basic.lean,Mathlib/Algebra/Bounds.lean,Mathlib/Algebra/CovariantAndContravariant.lean,Mathlib/Algebra/DirectSum/Internal.lean,Mathlib/Algebra/Group/UniqueProds.lean,Mathlib/Algebra/GroupPower/Order.lean,Mathlib/Algebra/MonoidAlgebra/Degree.lean,Mathlib/Algebra/Order/Archimedean.lean,Mathlib/Algebra/Order/Group/Abs.lean,Mathlib/Algebra/Order/Group/Defs.lean,Mathlib/Algebra/Order/Group/DenselyOrdered.lean,Mathlib/Algebra/Order/Group/MinMax.lean,Mathlib/Algebra/Order/Group/OrderIso.lean,Mathlib/Algebra/Order/Hom/Monoid.lean,Mathlib/Algebra/Order/Interval.lean,Mathlib/Algebra/Order/Kleene.lean,Mathlib/Algebra/Order/LatticeGroup.lean,Mathlib/Algebra/Order/Module.lean,Mathlib/Algebra/Order/Monoid/Basic.lean,Mathlib/Algebra/Order/Monoid/Cancel/Defs.lean,Mathlib/Algebra/Order/Monoid/Canonical/Defs.lean,Mathlib/Algebra/Order/Monoid/Defs.lean,Mathlib/Algebra/Order/Monoid/Lemmas.lean,Mathlib/Algebra/Order/Monoid/MinMax.lean,Mathlib/Algebra/Order/Monoid/NatCast.lean,Mathlib/Algebra/Order/Monoid/OrderDual.lean,Mathlib/Algebra/Order/Monoid/Prod.lean,Mathlib/Algebra/Order/Monoid/WithTop.lean,Mathlib/Algebra/Order/Monoid/WithZero/Basic.lean,Mathlib/Algebra/Order/Monoid/WithZero/Defs.lean,Mathlib/Algebra/Order/Nonneg/Ring.lean,Mathlib/Algebra/Order/Pointwise.lean,Mathlib/Algebra/Order/Positive/Ring.lean,Mathlib/Algebra/Order/Ring/Canonical.lean,Mathlib/Algebra/Order/Ring/Defs.lean,Mathlib/Algebra/Order/Ring/Lemmas.lean,Mathlib/Algebra/Order/Sub/Basic.lean,Mathlib/Algebra/Order/Sub/Canonical.lean,Mathlib/Algebra/Order/Sub/Defs.lean,Mathlib/Algebra/Order/WithZero.lean,Mathlib/Algebra/Parity.lean,Mathlib/Algebra/Star/Order.lean,Mathlib/Algebra/Tropical/Basic.lean,Mathlib/Analysis/Normed/Order/Lattice.lean,Mathlib/Data/DFinsupp/Lex.lean,Mathlib/Data/DFinsupp/Order.lean,Mathlib/Data/Finset/Fold.lean,Mathlib/Data/Finsupp/Lex.lean,Mathlib/Data/Finsupp/Order.lean,Mathlib/Data/List/BigOperators/Basic.lean,Mathlib/Data/List/BigOperators/Lemmas.lean,Mathlib/Data/Multiset/Basic.lean,Mathlib/Data/Nat/Cast/Order.lean,Mathlib/Data/PNat/Basic.lean,Mathlib/Data/Real/ENNReal.lean,Mathlib/Data/Real/NNReal.lean,Mathlib/Data/Set/Semiring.lean,Mathlib/Data/Sign.lean,Mathlib/MeasureTheory/Function/LpOrder.lean,Mathlib/MeasureTheory/Function/SimpleFuncDenseLp.lean,Mathlib/MeasureTheory/Measure/MeasureSpace.lean,Mathlib/MeasureTheory/Measure/VectorMeasure.lean,Mathlib/Order/ConditionallyCompleteLattice/Group.lean,Mathlib/Order/Filter/Basic.lean,Mathlib/Order/Filter/Pointwise.lean,Mathlib/Probability/Martingale/Basic.lean,Mathlib/Probability/Process/Stopping.lean,Mathlib/RingTheory/GradedAlgebra/Basic.lean,Mathlib/SetTheory/Cardinal/Basic.lean,Mathlib/SetTheory/Game/Basic.lean,Mathlib/SetTheory/Game/PGame.lean,Mathlib/SetTheory/Ordinal/Arithmetic.lean,Mathlib/SetTheory/Ordinal/Basic.lean,Mathlib/SetTheory/Ordinal/NaturalOps.lean,Mathlib/Tactic/GCongr/Core.lean,Mathlib/Tactic/Positivity/Basic.lean,Mathlib/Topology/ContinuousFunction/Algebra.lean,lean-toolchain,test/Recall.lean,test/propose.lean	81	36	['adomani', 'alreadydone', 'digama0', 'eric-wieser', 'ericrbg', 'jcommelin', 'leanprover-bot', 'sgouezel']	nobody	470-81464 1 year ago	492-62168 1 year ago	35-56459 35 days
6491	eric-wieser author:eric-wieser	chore(Mathlib/Algebra/Hom/GroupAction): add `SMulHomClass.comp_smul`	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	24/10	Mathlib/Algebra/Hom/GroupAction.lean	1	0	[]	nobody	470-81463 1 year ago	492-62168 1 year ago	83-76369 83 days
6993	jjaassoonn author:jjaassoonn	feat : lemmas about `AddMonoidAlgebra.{divOf, modOf}`	--- - [x] depends on: #7582 - [x] depends on: #8975 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	147/3	Mathlib/Algebra/MonoidAlgebra/Division.lean,Mathlib/Data/Finsupp/Basic.lean,Mathlib/Data/MvPolynomial/Basic.lean,Mathlib/Data/MvPolynomial/CommRing.lean,Mathlib/Data/MvPolynomial/Division.lean	5	42	['YaelDillies', 'alreadydone', 'digama0', 'eric-wieser', 'github-actions', 'jjaassoonn', 'leanprover-community-mathlib4-bot']	nobody	470-81463 1 year ago	492-62168 1 year ago	102-21189 102 days
10629	madvorak author:madvorak	feat: List.cons_sublist_append_iff_right	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data merge-conflict	11/0	Mathlib/Data/List/Basic.lean	1	1	['eric-wieser']	nobody	456-75008 1 year ago	456-75008 1 year ago	53-73442 53 days
13791	digama0 author:digama0	refactor: Primrec and Partrec	General cleanup of the `Primrec` and `Partrec` files, to better adjust to lean 4 things. The main user-visible change is that `Primrec₂` is no longer a `def` but an `abbrev`, because it was causing inference issues in lean 4. I also removed all the nonterminal `simp`s in `PartrecCode.lean`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	tech debt t-computability merge-conflict	585/778	Mathlib/Computability/Ackermann.lean,Mathlib/Computability/Halting.lean,Mathlib/Computability/Partrec.lean,Mathlib/Computability/PartrecCode.lean,Mathlib/Computability/Primrec.lean	5	2	['github-actions', 'grunweg']	nobody	452-37853 1 year ago	492-62168 1 year ago	1-84718 1 day
11964	adamtopaz author:adamtopaz	feat: The functor of points of a scheme	We construct the functor of points functor, and prove that it's full and faithful. --- - [ ] depends on: #11947 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebraic-geometry t-category-theory merge-conflict	210/0	Mathlib.lean,Mathlib/AlgebraicGeometry/FunctorOfPoints.lean,Mathlib/AlgebraicGeometry/OpenImmersion.lean	3	4	['github-actions', 'grunweg', 'leanprover-community-mathlib4-bot']	nobody	452-37712 1 year ago	492-62168 1 year ago	0-1223 20 minutes
12418	rosborn author:rosborn	style: replace preimage_val with ↓∩ notation	--- This is a rough draft of what the new `↓∩` notation would look like within mathlib. I believe this is an improvement in clarity and would like to have `↓∩` as a standard notation (along with `''`, `⁻¹'`, `↑`, etc...). As `↓∩` is specialized for `Set`s, I have only changed `preimage_val` when the left-hand side of `↓∩` is a `Set`. The introduction of the `↓∩` notation to Data.Set.Image is temporary as it isn't possible to import Data.Set.Subset directly. If we want `↓∩` unscoped, where would be the best place to define it? An option is Data.Set.Defs, but the notation cannot be defined without additional imports as the file does not import `notation3`. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict	56/61	Mathlib/Analysis/InnerProductSpace/Projection.lean,Mathlib/Data/Set/Function.lean,Mathlib/Data/Set/Image.lean,Mathlib/Data/Set/Subset.lean,Mathlib/MeasureTheory/Constructions/Polish.lean,Mathlib/MeasureTheory/MeasurableSpace/Basic.lean,Mathlib/MeasureTheory/Measure/Restrict.lean,Mathlib/Order/UpperLower/Basic.lean,Mathlib/Topology/Bases.lean,Mathlib/Topology/Clopen.lean,Mathlib/Topology/Connected/Basic.lean,Mathlib/Topology/Connected/PathConnected.lean,Mathlib/Topology/Constructions.lean,Mathlib/Topology/ContinuousOn.lean,Mathlib/Topology/LocalAtTarget.lean,Mathlib/Topology/LocallyConstant/Basic.lean,Mathlib/Topology/Separation.lean,Mathlib/Topology/Sober.lean	18	3	['grunweg', 'rosborn']	nobody	452-37611 1 year ago	492-62168 1 year ago	29-14218 29 days
12751	Command-Master author:Command-Master	feat: add lemmas for Nat/Bits, Nat/Bitwise and Nat/Size	Remove `@[simp]` from `Nat.bit_false` and `Nat.bit_true`, as `bit0` and `bit1` are deprecated, and add some lemmas to `Bits`, `Bitwise` and `Size`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data new-contributor merge-conflict	66/7	Mathlib/Data/Nat/Bits.lean,Mathlib/Data/Nat/Bitwise.lean,Mathlib/Data/Nat/Multiplicity.lean,Mathlib/Data/Nat/Size.lean	4	26	['Command-Master', 'Rida-Hamadani', 'Ruben-VandeVelde', 'YaelDillies', 'github-actions', 'jcommelin']	nobody	451-58765 1 year ago	456-75007 1 year ago	54-52408 54 days
16464	Parcly-Taxel author:Parcly-Taxel	chore: deprecate `Nat.(case_)strong_induction_on`	…in favour of the now-renamed `Nat.(case)strongInductionOn` in core.	tech debt merge-conflict	54/56	Archive/Imo/Imo1981Q3.lean,Mathlib/Algebra/ContinuedFractions/Computation/Approximations.lean,Mathlib/Algebra/ContinuedFractions/Computation/TerminatesIffRat.lean,Mathlib/Algebra/ContinuedFractions/ConvergentsEquiv.lean,Mathlib/Algebra/Polynomial/Derivative.lean,Mathlib/Algebra/Polynomial/Lifts.lean,Mathlib/Analysis/Analytic/Basic.lean,Mathlib/Analysis/Calculus/ContDiff/Bounds.lean,Mathlib/Analysis/Hofer.lean,Mathlib/Analysis/SpecificLimits/Normed.lean,Mathlib/Combinatorics/Derangements/Finite.lean,Mathlib/Combinatorics/Enumerative/Catalan.lean,Mathlib/Combinatorics/Hall/Finite.lean,Mathlib/Combinatorics/SetFamily/AhlswedeZhang.lean,Mathlib/Computability/Primrec.lean,Mathlib/Data/Fintype/Basic.lean,Mathlib/Data/Fintype/Card.lean,Mathlib/Data/Nat/Choose/Central.lean,Mathlib/Data/Nat/Defs.lean,Mathlib/Data/Nat/Digits.lean,Mathlib/Data/Nat/Log.lean,Mathlib/FieldTheory/Separable.lean,Mathlib/LinearAlgebra/Eigenspace/Triangularizable.lean,Mathlib/LinearAlgebra/Multilinear/Basic.lean,Mathlib/NumberTheory/BernoulliPolynomials.lean,Mathlib/NumberTheory/DiophantineApproximation.lean,Mathlib/NumberTheory/Pell.lean,Mathlib/NumberTheory/Primorial.lean,Mathlib/Order/Fin/Basic.lean,Mathlib/RingTheory/Adjoin/PowerBasis.lean,Mathlib/RingTheory/LittleWedderburn.lean,Mathlib/RingTheory/Polynomial/Basic.lean,Mathlib/RingTheory/Polynomial/Cyclotomic/Basic.lean,Mathlib/RingTheory/Polynomial/Cyclotomic/Eval.lean,Mathlib/RingTheory/Polynomial/Eisenstein/IsIntegral.lean,Mathlib/RingTheory/Polynomial/Nilpotent.lean,Mathlib/RingTheory/PowerSeries/Basic.lean,Mathlib/RingTheory/QuotientNilpotent.lean,Mathlib/RingTheory/WittVector/Defs.lean,Mathlib/RingTheory/WittVector/Frobenius.lean,Mathlib/RingTheory/WittVector/StructurePolynomial.lean,Mathlib/SetTheory/Surreal/Dyadic.lean,Mathlib/Topology/Metrizable/Uniformity.lean	43	13	['Parcly-Taxel', 'b-mehta', 'github-actions', 'jcommelin']	nobody	419-47321 1 year ago	419-47321 1 year ago	8-1989 8 days
17127	FR-vdash-bot author:FR-vdash-bot	chore: remove global `Quotient.mk` `⟦·⟧` notation	--- Merge this PR when we are ready to migrate to `QuotLike` API (#16421). [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data merge-conflict	137/2	Counterexamples/Pseudoelement.lean,Mathlib/Algebra/Associated/Basic.lean,Mathlib/Algebra/BigOperators/Group/Finset.lean,Mathlib/Algebra/Group/Conj.lean,Mathlib/Algebra/GroupWithZero/NonZeroDivisors.lean,Mathlib/Algebra/Order/CauSeq/Completion.lean,Mathlib/Algebra/Quandle.lean,Mathlib/AlgebraicGeometry/EllipticCurve/Jacobian.lean,Mathlib/AlgebraicGeometry/EllipticCurve/Projective.lean,Mathlib/AlgebraicTopology/FundamentalGroupoid/Basic.lean,Mathlib/AlgebraicTopology/FundamentalGroupoid/FundamentalGroup.lean,Mathlib/AlgebraicTopology/FundamentalGroupoid/InducedMaps.lean,Mathlib/AlgebraicTopology/FundamentalGroupoid/Product.lean,Mathlib/AlgebraicTopology/FundamentalGroupoid/SimplyConnected.lean,Mathlib/CategoryTheory/Abelian/Pseudoelements.lean,Mathlib/CategoryTheory/Limits/Shapes/SingleObj.lean,Mathlib/CategoryTheory/Monoidal/Free/Basic.lean,Mathlib/CategoryTheory/Monoidal/Free/Coherence.lean,Mathlib/CategoryTheory/Skeletal.lean,Mathlib/Data/Finset/Card.lean,Mathlib/Data/Fintype/List.lean,Mathlib/Data/Fintype/Quotient.lean,Mathlib/Data/Multiset/Basic.lean,Mathlib/Data/QPF/Multivariate/Constructions/Fix.lean,Mathlib/Data/QPF/Univariate/Basic.lean,Mathlib/Data/Quot.lean,Mathlib/Data/Real/Basic.lean,Mathlib/Data/Set/Finite.lean,Mathlib/Data/Set/Image.lean,Mathlib/Data/Setoid/Basic.lean,Mathlib/GroupTheory/GroupAction/Basic.lean,Mathlib/GroupTheory/GroupAction/Quotient.lean,Mathlib/LinearAlgebra/Dual.lean,Mathlib/LinearAlgebra/Ray.lean,Mathlib/Logic/Encodable/Basic.lean,Mathlib/Logic/Equiv/Basic.lean,Mathlib/ModelTheory/DirectLimit.lean,Mathlib/ModelTheory/Fraisse.lean,Mathlib/ModelTheory/Quotients.lean,Mathlib/NumberTheory/NumberField/CanonicalEmbedding/FundamentalCone.lean,Mathlib/NumberTheory/NumberField/Embeddings.lean,Mathlib/NumberTheory/NumberField/Units/DirichletTheorem.lean,Mathlib/NumberTheory/Padics/PadicIntegers.lean,Mathlib/NumberTheory/Padics/PadicNumbers.lean,Mathlib/Order/RelIso/Basic.lean,Mathlib/RepresentationTheory/Action/Concrete.lean,Mathlib/SetTheory/Cardinal/Basic.lean,Mathlib/SetTheory/Cardinal/Ordinal.lean,Mathlib/SetTheory/Game/Basic.lean,Mathlib/SetTheory/Game/Birthday.lean,Mathlib/SetTheory/Game/Impartial.lean,Mathlib/SetTheory/Game/Ordinal.lean,Mathlib/SetTheory/Game/State.lean,Mathlib/SetTheory/Lists.lean,Mathlib/SetTheory/Ordinal/Arithmetic.lean,Mathlib/SetTheory/Ordinal/Basic.lean,Mathlib/SetTheory/Surreal/Basic.lean,Mathlib/SetTheory/Surreal/Dyadic.lean,Mathlib/SetTheory/Surreal/Multiplication.lean,Mathlib/SetTheory/ZFC/Basic.lean,Mathlib/SetTheory/ZFC/Rank.lean,Mathlib/Topology/Connected/PathConnected.lean,Mathlib/Topology/Homotopy/HomotopyGroup.lean,Mathlib/Topology/Homotopy/Path.lean,Mathlib/Topology/Homotopy/Product.lean,Mathlib/Topology/MetricSpace/GromovHausdorff.lean,Mathlib/Topology/UniformSpace/Separation.lean,test/interactiveUnfold.lean	68	1	['github-actions']	nobody	410-9704 1 year ago	410-9704 1 year ago	4-72805 4 days
8029	alreadydone author:alreadydone	refactor: Homotopy between Functions not ContinuousMaps	This allows talking about homotopies without needing to supply proofs of continuity for the two ends. This for example simplifies the definition of H-spaces. Of course, if a homotopy exists between two functions, those two functions are automatically continuous because they are restrictions of the homotopy (which is continuous) to subspaces. `Homotopy.refl` still needs a continuous map as input, and `Homotopic` is only an equivalence relation when restricted to ContinuousMap. --- TODO: fix docstrings [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology RFC merge-conflict	246/250	Mathlib/AlgebraicTopology/FundamentalGroupoid/InducedMaps.lean,Mathlib/Topology/Homotopy/Basic.lean,Mathlib/Topology/Homotopy/Contractible.lean,Mathlib/Topology/Homotopy/Equiv.lean,Mathlib/Topology/Homotopy/HSpaces.lean,Mathlib/Topology/Homotopy/HomotopyGroup.lean,Mathlib/Topology/Homotopy/Path.lean,Mathlib/Topology/Homotopy/Product.lean	8	3	['alreadydone', 'urkud']	nobody	400-38509 1 year ago	492-62168 1 year ago	9-20043 9 days
14598	Command-Master author:Command-Master	chore: add typeclasses to unify various `add_top`, `add_eq_top`, etc.	Add the four typeclasses `IsTopAbsorbing`, `IsBotAbsorbing`, `NoTopSum`, `NoBotSum`, as additive equivalents for `MulZeroClass` and `NoZeroDivisors`. Add instances of these for `ENNReal`, `WithTop α`, `WithBot α`, `PUnit`, `EReal`, `PartENat`, `Measure`, `Interval` and `Filter`. Also split `Algebra/Order/AddGroupWithTop` to `Algebra/Order/Group/WithTop` and `Algebra/Order/Monoid/WithTop` --- Previous usages of lemmas with quantified names like `WithTop.add_top` have to be changed to just `add_top`. `add_lt_top` is `@[simp]`, in accordance with `ENNReal.add_lt_top` being `@[simp]`. This affects `WithTop.add_lt_top` which previously hadn't been `@[simp]`. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-order t-algebra merge-conflict label:t-algebra$	264/195	Archive/Wiedijk100Theorems/BallotProblem.lean,Mathlib.lean,Mathlib/Algebra/Order/Group/WithTop.lean,Mathlib/Algebra/Order/GroupWithZero/Canonical.lean,Mathlib/Algebra/Order/Interval/Basic.lean,Mathlib/Algebra/Order/Monoid/Unbundled/Basic.lean,Mathlib/Algebra/Order/Monoid/Unbundled/Defs.lean,Mathlib/Algebra/Order/Monoid/Unbundled/WithTop.lean,Mathlib/Algebra/Order/Monoid/WithTop.lean,Mathlib/Algebra/PUnitInstances/Order.lean,Mathlib/Algebra/Polynomial/Degree/Definitions.lean,Mathlib/Algebra/Polynomial/Monic.lean,Mathlib/Algebra/Tropical/Basic.lean,Mathlib/Analysis/Analytic/Meromorphic.lean,Mathlib/Analysis/Normed/Lp/ProdLp.lean,Mathlib/Analysis/NormedSpace/ENorm.lean,Mathlib/Analysis/SpecialFunctions/JapaneseBracket.lean,Mathlib/Analysis/SpecialFunctions/Log/ENNRealLog.lean,Mathlib/Data/ENNReal/Operations.lean,Mathlib/Data/ENat/Basic.lean,Mathlib/Data/Nat/PartENat.lean,Mathlib/Data/Nat/WithBot.lean,Mathlib/Data/Real/EReal.lean,Mathlib/LinearAlgebra/Lagrange.lean,Mathlib/MeasureTheory/Covering/Differentiation.lean,Mathlib/MeasureTheory/Decomposition/Lebesgue.lean,Mathlib/MeasureTheory/Function/ConditionalExpectation/CondexpL1.lean,Mathlib/MeasureTheory/Function/Jacobian.lean,Mathlib/MeasureTheory/Function/L1Space.lean,Mathlib/MeasureTheory/Function/L2Space.lean,Mathlib/MeasureTheory/Function/LpSeminorm/Basic.lean,Mathlib/MeasureTheory/Function/LpSeminorm/TriangleInequality.lean,Mathlib/MeasureTheory/Function/LpSpace.lean,Mathlib/MeasureTheory/Function/StronglyMeasurable/Basic.lean,Mathlib/MeasureTheory/Function/UniformIntegrable.lean,Mathlib/MeasureTheory/Integral/Bochner.lean,Mathlib/MeasureTheory/Integral/MeanInequalities.lean,Mathlib/MeasureTheory/Integral/SetIntegral.lean,Mathlib/MeasureTheory/Integral/VitaliCaratheodory.lean,Mathlib/MeasureTheory/Measure/Hausdorff.lean,Mathlib/MeasureTheory/Measure/Lebesgue/Basic.lean,Mathlib/MeasureTheory/Measure/LevyProkhorovMetric.lean,Mathlib/MeasureTheory/Measure/MeasureSpace.lean,Mathlib/MeasureTheory/Measure/MeasureSpaceDef.lean,Mathlib/MeasureTheory/Measure/Regular.lean,Mathlib/MeasureTheory/Measure/Typeclasses.lean,Mathlib/NumberTheory/Padics/PadicNumbers.lean,Mathlib/Order/Filter/Pointwise.lean,Mathlib/Probability/Kernel/Defs.lean,Mathlib/Probability/Martingale/Convergence.lean,Mathlib/RingTheory/Multiplicity.lean,Mathlib/RingTheory/MvPowerSeries/NoZeroDivisors.lean,Mathlib/RingTheory/UniqueFactorizationDomain.lean,Mathlib/Topology/EMetricSpace/Defs.lean,Mathlib/Topology/MetricSpace/Bounded.lean,Mathlib/Topology/MetricSpace/HausdorffDistance.lean,Mathlib/Topology/MetricSpace/Lipschitz.lean	57	30	['Command-Master', 'YaelDillies', 'github-actions']	nobody	373-5170 1 year ago	373-5170 1 year ago	7-45599 7 days
12778	MichaelStollBayreuth author:MichaelStollBayreuth	perf: decouple algebraic and order hierarchies in type class search	Based on the experience gained with [#12680](https://github.com/leanprover-community/mathlib4/pull/12680), this attempts to decouple the algebraic and order hierarchies in type class search. * We lower the priorities of instances like `OrderedSemiring.toSemiring` (which are generated by the `extends` clause with default priority 1000) to 50. * Additionally, we make the default priority available via `open scoped AlgebraOrderInstances` and use that where appropriate. Motivation: Looking at instance synthesization traces, it appears that when (e.g.) presented with the goal to find a `Semiring` instance, the algorithm frequently goes down a rabbit hole trying and failing to find order instances. This seems to be caused by the presence of instances like `OrderedSemiring.toSemiring` with default priority, which are tried early in the search, but lead nowhere (after a fairly long time). These instances are created by declarations of the form ```lean class OrderedSemiring (α : Type u) extends Semiring α, OrderedAddCommMonoid α where ... ``` which automatically sets up (among other things) an instance `OrderedSemiring.toSemiring` with default piority. It appears that these instances cannot be removed completely (only locally in a module), so the next best solution is to make them low priority (which is possible also for downstream modules). To provide for situations where these instances are desired, we put a default priority version in the scope `AlgebraOrderInstances`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	slow-typeclass-synthesis t-order t-algebra merge-conflict label:t-algebra$	306/27	Mathlib/Algebra/Algebra/Subalgebra/Order.lean,Mathlib/Algebra/ContinuedFractions/Computation/ApproximationCorollaries.lean,Mathlib/Algebra/ContinuedFractions/Computation/Approximations.lean,Mathlib/Algebra/Module/Rat.lean,Mathlib/Algebra/Module/Submodule/Order.lean,Mathlib/Algebra/Order/AbsoluteValue.lean,Mathlib/Algebra/Order/Algebra.lean,Mathlib/Algebra/Order/Antidiag/Prod.lean,Mathlib/Algebra/Order/Archimedean/Basic.lean,Mathlib/Algebra/Order/BigOperators/Group/Finset.lean,Mathlib/Algebra/Order/BigOperators/Group/List.lean,Mathlib/Algebra/Order/BigOperators/Group/Multiset.lean,Mathlib/Algebra/Order/BigOperators/Ring/Finset.lean,Mathlib/Algebra/Order/BigOperators/Ring/List.lean,Mathlib/Algebra/Order/BigOperators/Ring/Multiset.lean,Mathlib/Algebra/Order/CauSeq/Basic.lean,Mathlib/Algebra/Order/Chebyshev.lean,Mathlib/Algebra/Order/CompleteField.lean,Mathlib/Algebra/Order/Field/Basic.lean,Mathlib/Algebra/Order/Field/Defs.lean,Mathlib/Algebra/Order/Field/Pi.lean,Mathlib/Algebra/Order/Floor.lean,Mathlib/Algebra/Order/Floor/Div.lean,Mathlib/Algebra/Order/Group/Defs.lean,Mathlib/Algebra/Order/Group/Units.lean,Mathlib/Algebra/Order/GroupWithZero/Canonical.lean,Mathlib/Algebra/Order/Hom/Basic.lean,Mathlib/Algebra/Order/Hom/Monoid.lean,Mathlib/Algebra/Order/Interval/Basic.lean,Mathlib/Algebra/Order/Interval/Set/Instances.lean,Mathlib/Algebra/Order/Invertible.lean,Mathlib/Algebra/Order/Kleene.lean,Mathlib/Algebra/Order/Module/Algebra.lean,Mathlib/Algebra/Order/Module/Defs.lean,Mathlib/Algebra/Order/Module/Pointwise.lean,Mathlib/Algebra/Order/Monoid/Basic.lean,Mathlib/Algebra/Order/Monoid/Canonical/Defs.lean,Mathlib/Algebra/Order/Monoid/Defs.lean,Mathlib/Algebra/Order/Monoid/OrderDual.lean,Mathlib/Algebra/Order/Monoid/Prod.lean,Mathlib/Algebra/Order/Nonneg/Field.lean,Mathlib/Algebra/Order/Nonneg/Ring.lean,Mathlib/Algebra/Order/Pi.lean,Mathlib/Algebra/Order/Positive/Field.lean,Mathlib/Algebra/Order/Positive/Ring.lean,Mathlib/Algebra/Order/Rearrangement.lean,Mathlib/Algebra/Order/Ring/Basic.lean,Mathlib/Algebra/Order/Ring/Defs.lean,Mathlib/Algebra/Order/Ring/InjSurj.lean,Mathlib/Algebra/Order/Ring/Pow.lean,Mathlib/Algebra/Order/Sub/WithTop.lean,Mathlib/Algebra/Order/ToIntervalMod.lean,Mathlib/Algebra/Ring/BooleanRing.lean,Mathlib/AlgebraicGeometry/Morphisms/RingHomProperties.lean,Mathlib/AlgebraicTopology/FundamentalGroupoid/Basic.lean,Mathlib/Analysis/BoundedVariation.lean,Mathlib/Analysis/Complex/UpperHalfPlane/Metric.lean,Mathlib/Analysis/Convex/Basic.lean,Mathlib/Analysis/Convex/Cone/Basic.lean,Mathlib/Analysis/Convex/Cone/Closure.lean,Mathlib/Analysis/Convex/Cone/Pointed.lean,Mathlib/Analysis/Convex/Cone/Proper.lean,Mathlib/Analysis/Convex/Exposed.lean,Mathlib/Analysis/Convex/Extrema.lean,Mathlib/Analysis/Convex/Function.lean,Mathlib/Analysis/Convex/Gauge.lean,Mathlib/Analysis/Convex/GaugeRescale.lean,Mathlib/Analysis/Convex/Hull.lean,Mathlib/Analysis/Convex/Join.lean,Mathlib/Analysis/Convex/Mul.lean,Mathlib/Analysis/Convex/Quasiconvex.lean,Mathlib/Analysis/Convex/SpecificFunctions/Pow.lean,Mathlib/Analysis/Convex/Star.lean,Mathlib/Analysis/Convex/Strict.lean,Mathlib/Analysis/InnerProductSpace/Orientation.lean,Mathlib/Analysis/MeanInequalities.lean,Mathlib/Analysis/SpecialFunctions/Gamma/BohrMollerup.lean,Mathlib/Analysis/SpecialFunctions/Polynomials.lean,Mathlib/Analysis/SpecificLimits/FloorPow.lean,Mathlib/Analysis/SpecificLimits/Normed.lean,Mathlib/Combinatorics/Optimization/ValuedCSP.lean,Mathlib/Combinatorics/Pigeonhole.lean,Mathlib/Combinatorics/SetFamily/FourFunctions.lean,Mathlib/Data/DFinsupp/Lex.lean,Mathlib/Data/DFinsupp/Multiset.lean,Mathlib/Data/DFinsupp/Order.lean,Mathlib/Data/Finset/MulAntidiagonal.lean,Mathlib/Data/Finsupp/Lex.lean,Mathlib/Data/Finsupp/Multiset.lean,Mathlib/Data/Finsupp/Order.lean,Mathlib/Data/Int/Log.lean,Mathlib/Data/Multiset/Antidiagonal.lean,Mathlib/Data/Multiset/Basic.lean,Mathlib/Data/Multiset/Bind.lean,Mathlib/Data/Nat/Cast/Field.lean,Mathlib/Data/Nat/Cast/Order/Basic.lean,Mathlib/Data/Nat/Choose/Bounds.lean,Mathlib/Data/PNat/Factors.lean,Mathlib/Data/Rat/Denumerable.lean,Mathlib/Data/Set/Pointwise/Interval.lean	135	34	['MichaelStollBayreuth', 'YaelDillies', 'github-actions', 'leanprover-bot']	nobody	373-4073 1 year ago	373-4073 1 year ago	18-19513 18 days
19212	Julian author:Julian	feat(LinearAlgebra): add a variable_alias for VectorSpace	Taken directly from the variable_alias docs. Zulip: https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/why.20.5Bvariable_alias.5D.20attribute.20is.20not.20used.20in.20Mathlib.3F --- This is the first actual variable alias added to mathlib. I haven't reviewed variable_alias fully, but it seems like there's at least 3 ways they could be distributed in Mathlib: * alongside whatever subfolder they "belong to" (which is what I've tentatively done here) * In a file called `Aliases` somewhere near the thing they alias (which seems less discoverable to me) * In a single file, a la `Mathlib.TrainingWheels` (with some less playful name) which is meant to define a bunch of more "friendly" aliases all in one place. I kind of like the idea of the third thing as a future module but perhaps it can be synthesized if/when there are more aliases? For now as I say I've done the first one, but please let me know if someone prefers something else. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	25/0	Mathlib.lean,Mathlib/LinearAlgebra/VectorSpace.lean,scripts/noshake.json	3	10	['Julian', 'PieterCuijpers', 'github-actions', 'urkud']	nobody	352-68325 11 months ago	352-68325 11 months ago	7-68492 7 days
19337	zeramorphic author:zeramorphic	feat(Data/Finsupp): generalise `Finsupp` to any "zero" value	Remove the explicit dependence of `Finsupp` on `[Zero M]`, instead defining `Finsupp'` (better name pending) to be functions that are equal to a fixed value `z : M` cofinitely often. This PR is intended to do the initial work of replacing the definition of `Finsupp` with an instantiation of the more general definition, without adding any appropriate API. If accepted, the API development will follow in later PRs. Issues to consider: - Naming of `Finsupp'.` - Where should `Finsupp'` lemmas go? Do they need their own file/folder under `Data/`? Relevant Zulip threads: - https://leanprover.zulipchat.com/#narrow/channel/217875-Is-there-code-for-X.3F/topic/Finsupp.20generalisations - https://leanprover.zulipchat.com/#narrow/channel/217875-Is-there-code-for-X.3F/topic/Finsupp-like.20partial.20function Comments are welcome. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data merge-conflict	203/83	Archive/Wiedijk100Theorems/Partition.lean,Mathlib/Algebra/MvPolynomial/Basic.lean,Mathlib/Algebra/MvPolynomial/Rename.lean,Mathlib/Algebra/MvPolynomial/Variables.lean,Mathlib/Algebra/Polynomial/Basic.lean,Mathlib/Algebra/Polynomial/Laurent.lean,Mathlib/Data/Finsupp/BigOperators.lean,Mathlib/Data/Finsupp/Defs.lean,Mathlib/Data/Finsupp/Order.lean,Mathlib/Data/Nat/Choose/Multinomial.lean,Mathlib/RingTheory/MvPolynomial/Symmetric/Defs.lean,Mathlib/RingTheory/PowerBasis.lean,scripts/nolints_prime_decls.txt	13	5	['github-actions', 'vihdzp', 'zeramorphic']	nobody	350-44402 11 months ago	350-44402 11 months ago	4-60621 4 days
18756	astrainfinita author:astrainfinita	refactor: deprecate `DistribMulActionSemiHomClass` `MulSemiringActionSemiHomClass`	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	50/28	Mathlib/Algebra/Algebra/NonUnitalHom.lean,Mathlib/Algebra/Module/LinearMap/Defs.lean,Mathlib/GroupTheory/GroupAction/Hom.lean	3	4	['astrainfinita', 'github-actions', 'leanprover-bot']	nobody	339-10071 11 months ago	339-10071 11 months ago	31-75259 31 days
18748	FR-vdash-bot author:FR-vdash-bot	refactor: deprecate `ContinuousLinearMapClass`	--- - [ ] depends on: #18689 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra t-topology merge-conflict label:t-algebra$	115/49	Mathlib/Analysis/CStarAlgebra/Spectrum.lean,Mathlib/Analysis/LocallyConvex/WeakOperatorTopology.lean,Mathlib/Analysis/Normed/Algebra/Spectrum.lean,Mathlib/Analysis/Normed/Operator/LinearIsometry.lean,Mathlib/Topology/Algebra/Module/Basic.lean,Mathlib/Topology/Algebra/Module/CharacterSpace.lean,Mathlib/Topology/Algebra/Module/FiniteDimension.lean,Mathlib/Topology/Algebra/Module/StrongTopology.lean,Mathlib/Topology/Algebra/Module/WeakDual.lean,Mathlib/Topology/Homeomorph.lean	10	5	['FR-vdash-bot', 'github-actions', 'leanprover-bot', 'mathlib4-dependent-issues-bot']	nobody	332-60484 10 months ago	332-60487 10 months ago	0-989 16 minutes
20527	trivial1711 author:trivial1711	refactor(Topology/UniformSpace/Completion): more descriptive names for `α → Completion α`	- We rename the various maps `α → Completion α` in order to make their names more consistent. - Let `α` be a uniform space. We rename the uniformly continuous function `α → Completion α` from `UniformSpace.Completion.coe'` to `UniformSpace.Completion.coe`. - Let `α` be a uniform additive group. We rename the additive group homomorphism `α →+ Completion α` from `UniformSpace.Completion.toCompl` to `UniformSpace.Completion.coeAddHom`. - Let `α` be a uniform ring. The ring homomorphism `α →+* Completion α` is called `UniformSpace.Completion.coeRingHom`; its name is unchanged. - Let `α` be a normed space over a field `𝕜`. We rename the linear isometry `α →ₗᵢ[𝕜] Completion α` from `UniformSpace.Completion.toComplₗᵢ` to `UniformSpace.Completion.coeₗᵢ`. - Let `α` be a normed space over a field `𝕜`. We rename the continuous linear map `α →L[𝕜] Completion α` from `UniformSpace.Completion.toComplL` to `UniformSpace.Completion.coeL`. - Let `α` be a normed additive group. We rename the norm preserving homomorphism `NormedAddGroupHom α (Completion α)` from `NormedAddCommGroup.toCompl` to `UniformSpace.Completion.coeNormedAddGroupHom`. - We analogously rename some other theorems. - We add some trivial theorems (all of which are proved by `rfl`) that state that the functions considered above are equal. We give all of them the `simp` and `norm_cast` attributes. - We add a new theorem `UniformSpace.Completion.coeAddHom_eq_coe` that states that `UniformSpace.Completion.coeAddHom` and `UniformSpace.Completion.coe` are equal as functions. - We similarly add a new theorem `UniformSpace.Completion.coeRingHom_eq_coe`. - We rename the theorem `UniformSpace.Completion.coe_toComplₗᵢ` to `UniformSpace.Completion.coeₗᵢ_eq_coe`. - We rename the theorem `UniformSpace.Completion.coe_toComplL` to `UniformSpace.Completion.coeL_eq_coe`. - We similarly add a new theorem `UniformSpace.Completion.coeNormedAddGroupHom_eq_coe`. - We change all occurrences of the string `((↑) : α → Completion α)` to `(coe : α → Completion α)` or just `coe`. - We put the statements of some theorems into simp normal form by using the plain function `coe` rather than the homomorphisms that carry more structure. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology merge-conflict	130/92	Mathlib/Analysis/Analytic/Uniqueness.lean,Mathlib/Analysis/Calculus/FDeriv/Analytic.lean,Mathlib/Analysis/Complex/AbsMax.lean,Mathlib/Analysis/Complex/Liouville.lean,Mathlib/Analysis/InnerProductSpace/Completion.lean,Mathlib/Analysis/Normed/Group/HomCompletion.lean,Mathlib/Analysis/Normed/Module/Completion.lean,Mathlib/Analysis/SpecialFunctions/NonIntegrable.lean,Mathlib/MeasureTheory/Integral/IntegralEqImproper.lean,Mathlib/Topology/Algebra/GroupCompletion.lean,Mathlib/Topology/Algebra/InfiniteSum/GroupCompletion.lean,Mathlib/Topology/Algebra/InfiniteSum/Nonarchimedean.lean,Mathlib/Topology/Algebra/Nonarchimedean/Completion.lean,Mathlib/Topology/Algebra/UniformRing.lean,Mathlib/Topology/Category/UniformSpace.lean,Mathlib/Topology/MetricSpace/Completion.lean,Mathlib/Topology/UniformSpace/Completion.lean	17	4	['eric-wieser', 'github-actions', 'trivial1711']	nobody	304-57277 10 months ago	304-57277 10 months ago	6-66637 6 days
18474	FR-vdash-bot author:FR-vdash-bot	perf: lower the priority of `WithOne.to` instances	--- From #7873. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data slow-typeclass-synthesis t-algebra merge-conflict label:t-algebra$	9/2	Mathlib/Algebra/Polynomial/BigOperators.lean,Mathlib/Data/Int/Cast/Defs.lean,Mathlib/Data/Nat/Cast/Defs.lean	3	7	['FR-vdash-bot', 'eric-wieser', 'github-actions', 'leanprover-bot']	nobody	302-44307 9 months ago	302-44307 9 months ago	76-67978 76 days
20372	jvlmdr author:jvlmdr	feat(MeasureTheory/Function): Add ContinuousLinearMap.bilinearCompLp(L)	Introduce ContinuousLinearMap.bilinearCompLp and bilinearCompLpL. Generalize eLpNorm_le_eLpNorm_mul_eLpNorm theorems to include constant C in bound condition. --- Expect this may be useful for defining tempered distributions from functions in `L^p`. The definitions more or less follow `ContinuousLinearMap.compLp...`. Names are loosely analogous to `ContinuousLinearMap.bilinearComp` and `SchwartzMap.bilinLeftCLM`. Note: I preferred the spelling `hpqr : p⁻¹ + q⁻¹ = r⁻¹` with `f` in `L^p` and `g` in `L^q` to `hpqr : 1 / p = 1 / q + 1 / r`. It's easier to obtain from `ENNReal.IsConjExponent` too. A few questions: - [ ] I defined `bilinear{Left,Right}LpL` in addition to `bilinearCompLpL` because `LinearMap.mkContinuous₂` is marked as `noncomputable` and `LinearMap.mkContinuous` is not. Is this worth the extra definitions? (Note: This is not visible in the source due to `noncomputable section`.) - [ ] Should I use `C : ℝ` instead of `C : NNReal` for `eLpNorm_le_eLpNorm_mul_eLpNorm'_of_norm'`? - [ ] Is it going to be painful to have `[Fact (1 ≤ p)] [Fact (1 ≤ q)] [Fact (1 ≤ r)]`? I don't think there's a way to avoid it though. Maybe providing specialized versions for `p.IsConjExponent q` with `L^1`? Naming: - [ ] Is it satisfactory to add a `'` to the `eLpNorm_le_eLpNorm_mul_eLpNorm ` definitions in `CompareExp.lean` where `≤ ‖f x‖ * ‖g x‖` has been replaced with `≤ C * ‖f x‖ * ‖g x‖`? These could replace the existing theorems, although I don't want to break backwards compatibility. There are 5 instances: `eLpNorm_le_eLpNorm_top_mul_eLpNorm'`, `eLpNorm_le_eLpNorm_mul_eLpNorm_top'`, `eLpNorm'_le_eLpNorm'_mul_eLpNorm''`, `eLpNorm_le_eLpNorm_mul_eLpNorm_of_nnnorm'`, `eLpNorm_le_eLpNorm_mul_eLpNorm'_of_norm'` (I'm not sure why the existing theorem `eLpNorm_le_eLpNorm_mul_eLpNorm'_of_norm` has an internal `'`) - [ ] Is `bilinearLeftLpL` a suitable name? Other options: `bilinearCompLpLeftL`, `bilinearCompLeftLpL`, `bilinLeftLpL` (analogous to `SchwartzMap.bilinLeftCLM`) [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-measure-probability merge-conflict	203/40	Mathlib/MeasureTheory/Function/LpSeminorm/CompareExp.lean,Mathlib/MeasureTheory/Function/LpSpace.lean	2	1	['github-actions']	nobody	289-68564 9 months ago	289-68564 9 months ago	27-43617 27 days
21099	chrisflav author:chrisflav	chore(RingTheory/Generators): use unification hints for variables and relations	When working with generators and presentations, we rely on the `MvPolynomial` API, but since the type of variables is bundled in `Generators R S`, many lemmas don't apply with `rw` or `simp`, because they can't see through the definition of `vars` in constructions such as `Generators.comp` and `Generators.localizationAway`. A possible approach is to make all of these constructions `abbrev`s, but this causes `simp` to also unfold `val` which is not always desirable. More generally, it is then harder to predict how instance search and `simp` behave. This approach is tried in #21050, but causes many regressions. This approach is less invasive, as it uses `unif_hint` to unify the `vars` (and `rels`) fields of constructions with the correct type. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	231/91	Mathlib/Algebra/Module/Presentation/Differentials.lean,Mathlib/RingTheory/Generators.lean,Mathlib/RingTheory/Kaehler/JacobiZariski.lean,Mathlib/RingTheory/Presentation.lean,Mathlib/RingTheory/Smooth/StandardSmooth.lean	5	16	['chrisflav', 'erdOne', 'github-actions', 'leanprover-bot', 'mattrobball']	nobody	263-51542 8 months ago	263-51542 8 months ago	27-75210 27 days
21959	BGuillemet author:BGuillemet	feat(Topology/ContinuousMap): Stone-Weierstrass theorem for MvPolynomial	Add the subalgebra of multivariate polynomials and prove it separates points, on the same model as `ContinuousMap/Polynomial.lean`. Prove the Stone-Weierstrass theorem and some variations for multivariate polynomials. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-topology merge-conflict	285/1	Mathlib.lean,Mathlib/Topology/ContinuousMap/MvPolynomial.lean,Mathlib/Topology/ContinuousMap/StoneWeierstrass.lean	3	1	['github-actions']	nobody	253-54585 8 months ago	253-54585 8 months ago	16-76141 16 days
22660	Ruben-VandeVelde author:Ruben-VandeVelde	chore: follow naming convention around Group.IsNilpotent	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	133/67	Mathlib/GroupTheory/Frattini.lean,Mathlib/GroupTheory/Nilpotent.lean,Mathlib/GroupTheory/SpecificGroups/ZGroup.lean	3	1	['github-actions']	nobody	241-76840 7 months ago	241-76840 7 months ago	10-48025 10 days
22701	ctchou author:ctchou	feat(Combinatorics): the Katona circle method	This file formalizes the Katona circle method. From PlainCombi (LeanCamCombi): https://github.com/YaelDillies/LeanCamCombi/blob/master/LeanCamCombi/PlainCombi/KatonaCircle.lean Co-authored-by: Yaël Dillies	new-contributor t-combinatorics merge-conflict	121/0	Mathlib.lean,Mathlib/Combinatorics/KatonaCircle.lean	2	1	['github-actions']	nobody	221-30354 7 months ago	221-30354 7 months ago	30-8337 30 days
23411	PatrickMassot author:PatrickMassot	chore: remove finiteness from Order.Filter.Lift	Co-authored-by: Anatole Dedecker --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	longest-pole t-topology merge-conflict	48/21	Mathlib/Dynamics/TopologicalEntropy/DynamicalEntourage.lean,Mathlib/Order/Filter/Basic.lean,Mathlib/Order/Filter/Finite.lean,Mathlib/Order/Filter/Lift.lean,Mathlib/Order/Filter/SmallSets.lean,Mathlib/Topology/Algebra/ContinuousMonoidHom.lean,Mathlib/Topology/Basic.lean	7	4	['Vierkantor', 'github-actions', 'kim-em', 'leanprover-community-bot-assistant']	nobody	219-77068 7 months ago	220-10237 7 months ago	10-21608 10 days
21488	imbrem author:imbrem	feat(CategoryTheory/Monoidal): premonoidal categories	Add support for premonoidal categories --- Still want to add support for: - Premonoidal braided/symmetric categories - The monoidal coherence theorem, which I've already ported in my `discretion` library - The `coherence` tactic, which should work fine for premonoidal categories too but wanted to get this in front of reviewers ASAP to make sure my general approach was alright [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-category-theory merge-conflict	900/361	Mathlib/Algebra/Category/ModuleCat/Presheaf/Monoidal.lean,Mathlib/CategoryTheory/Bicategory/End.lean,Mathlib/CategoryTheory/GradedObject/Monoidal.lean,Mathlib/CategoryTheory/Localization/Monoidal.lean,Mathlib/CategoryTheory/Monoidal/Braided/Basic.lean,Mathlib/CategoryTheory/Monoidal/Category.lean,Mathlib/CategoryTheory/Monoidal/Center.lean,Mathlib/CategoryTheory/Monoidal/CoherenceLemmas.lean,Mathlib/CategoryTheory/Monoidal/Discrete.lean,Mathlib/CategoryTheory/Monoidal/End.lean,Mathlib/CategoryTheory/Monoidal/Free/Basic.lean,Mathlib/CategoryTheory/Monoidal/Functor.lean,Mathlib/CategoryTheory/Monoidal/FunctorCategory.lean,Mathlib/CategoryTheory/Monoidal/Mon_.lean,Mathlib/CategoryTheory/Monoidal/Opposite.lean,Mathlib/CategoryTheory/Monoidal/Transport.lean,Mathlib/Tactic/CategoryTheory/Monoidal/Datatypes.lean,Mathlib/Tactic/CategoryTheory/Monoidal/Normalize.lean,Mathlib/Tactic/CategoryTheory/Monoidal/PureCoherence.lean,Mathlib/Tactic/CategoryTheory/MonoidalComp.lean,MathlibTest/StringDiagram.lean	21	9	['YaelDillies', 'github-actions', 'grunweg', 'imbrem', 'kim-em', 'leanprover-community-bot-assistant']	nobody	218-62987 7 months ago	218-62988 7 months ago	58-20339 58 days
21525	sinhp author:sinhp	feat(CategoryTheory): Locally Cartesian Closed Categories (Prelim)	This PR defines the basic preliminaries for defining locally cartesian closed categories (LCCCs). In particular, using the calculus of mates we define certain natural isomorphisms involving `Over.star` and `Over.pullback` which will be crucial in defining the right adjoint to the pullback functor in the development of LCCCs. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import t-category-theory merge-conflict	338/24	Mathlib/CategoryTheory/Comma/Over/Basic.lean,Mathlib/CategoryTheory/Comma/Over/Pullback.lean,Mathlib/CategoryTheory/Galois/Examples.lean	3	13	['b-mehta', 'github-actions', 'joelriou', 'leanprover-community-bot-assistant', 'sinhp']	nobody	218-62985 7 months ago	218-62987 7 months ago	43-83249 43 days
16314	FR-vdash-bot author:FR-vdash-bot	chore(Data/Quot): deprecate `ind*'` APIs	--- - [x] depends on: #16264 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data merge-conflict	247/287	Counterexamples/CliffordAlgebraNotInjective.lean,Mathlib/Algebra/Colimit/Module.lean,Mathlib/Algebra/Lie/Quotient.lean,Mathlib/Algebra/Module/Torsion.lean,Mathlib/Algebra/RingQuot.lean,Mathlib/Analysis/SpecialFunctions/Trigonometric/Angle.lean,Mathlib/CategoryTheory/ConnectedComponents.lean,Mathlib/CategoryTheory/Subobject/Basic.lean,Mathlib/CategoryTheory/Subobject/FactorThru.lean,Mathlib/CategoryTheory/Subobject/Lattice.lean,Mathlib/Computability/Reduce.lean,Mathlib/Computability/Tape.lean,Mathlib/Data/List/Cycle.lean,Mathlib/Data/Multiset/MapFold.lean,Mathlib/Data/Multiset/ZeroCons.lean,Mathlib/Data/Quot.lean,Mathlib/Data/Setoid/Basic.lean,Mathlib/Data/Setoid/Partition.lean,Mathlib/FieldTheory/Fixed.lean,Mathlib/GroupTheory/Complement.lean,Mathlib/GroupTheory/Congruence/Basic.lean,Mathlib/GroupTheory/Congruence/Defs.lean,Mathlib/GroupTheory/Congruence/Hom.lean,Mathlib/GroupTheory/Coset/Basic.lean,Mathlib/GroupTheory/Coset/Defs.lean,Mathlib/GroupTheory/FreeAbelianGroup.lean,Mathlib/GroupTheory/GroupAction/Basic.lean,Mathlib/GroupTheory/GroupAction/Defs.lean,Mathlib/GroupTheory/GroupAction/Quotient.lean,Mathlib/GroupTheory/Index.lean,Mathlib/GroupTheory/MonoidLocalization/Basic.lean,Mathlib/GroupTheory/PGroup.lean,Mathlib/GroupTheory/Perm/Cycle/Concrete.lean,Mathlib/GroupTheory/PresentedGroup.lean,Mathlib/GroupTheory/QuotientGroup/Basic.lean,Mathlib/GroupTheory/QuotientGroup/Defs.lean,Mathlib/GroupTheory/SchurZassenhaus.lean,Mathlib/GroupTheory/Sylow.lean,Mathlib/LinearAlgebra/Alternating/DomCoprod.lean,Mathlib/LinearAlgebra/Projectivization/Basic.lean,Mathlib/LinearAlgebra/Quotient/Basic.lean,Mathlib/LinearAlgebra/Quotient/Defs.lean,Mathlib/MeasureTheory/Function/AEEqFun.lean,Mathlib/NumberTheory/Padics/PadicNumbers.lean,Mathlib/NumberTheory/RamificationInertia/Basic.lean,Mathlib/Order/Antisymmetrization.lean,Mathlib/Order/Category/PartOrd.lean,Mathlib/Order/Filter/Germ/Basic.lean,Mathlib/RepresentationTheory/GroupCohomology/Hilbert90.lean,Mathlib/RingTheory/AdicCompletion/Algebra.lean,Mathlib/RingTheory/AdicCompletion/Basic.lean,Mathlib/RingTheory/AdicCompletion/Functoriality.lean,Mathlib/RingTheory/AdjoinRoot.lean,Mathlib/RingTheory/Congruence/Basic.lean,Mathlib/RingTheory/Flat/FaithfullyFlat/Basic.lean,Mathlib/RingTheory/GradedAlgebra/HomogeneousLocalization.lean,Mathlib/RingTheory/Ideal/Cotangent.lean,Mathlib/RingTheory/Ideal/Norm/AbsNorm.lean,Mathlib/RingTheory/Ideal/Quotient/Basic.lean,Mathlib/RingTheory/Ideal/Quotient/Defs.lean,Mathlib/RingTheory/Ideal/Quotient/Operations.lean,Mathlib/RingTheory/Valuation/Quotient.lean,Mathlib/Topology/Algebra/Group/TopologicalAbelianization.lean,Mathlib/Topology/Algebra/InfiniteSum/Module.lean,Mathlib/Topology/Separation/Basic.lean	65	4	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	213-1551 6 months ago	213-1553 6 months ago	55-52030 55 days
15483	FR-vdash-bot author:FR-vdash-bot	chore(GroupTheory/Coset): reduce defeq abuse	--- - [x] depends on: #15482 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	114/60	Mathlib/GroupTheory/Commensurable.lean,Mathlib/GroupTheory/Coset.lean,Mathlib/GroupTheory/QuotientGroup.lean,Mathlib/LinearAlgebra/Alternating/DomCoprod.lean,Mathlib/MeasureTheory/Measure/Haar/Quotient.lean,Mathlib/Topology/Algebra/Group/Compact.lean	6	14	['FR-vdash-bot', 'eric-wieser', 'github-actions', 'grunweg', 'leanprover-bot', 'leanprover-community-mathlib4-bot', 'mattrobball', 'mergify', 'urkud']	nobody	212-32844 6 months ago	460-71174 1 year ago	4-79214 4 days
20567	grunweg author:grunweg	feat(Cache): two small features	- add an informational message to the get command (when run without arguments): when more than 80% of all cache files present were not used in the last command, tell the user about the `clean` command --- - [ ] depends on #20568 (for the first feature) - [ ] TODO: re-design this feature and the clean command: if there are N local copies of mathlib, cache should have a pointer to all of them - to avoid clearing all N-1 from inside the last local copy [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-meta merge-conflict	38/2	Cache/Main.lean	1	11	['Julian', 'arthurpaulino', 'fpvandoorn', 'github-actions', 'grunweg']	nobody	210-36947 6 months ago	210-36947 6 months ago	1-17369 1 day
23859	urkud author:urkud	feat(Topology/../Order/Field): generalize to `Semifield`	.. from a linear ordered field to a linear ordered semifield--- - [ ] depends on: #23857 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology merge-conflict	245/219	Mathlib/Algebra/Order/Group/Pointwise/Interval.lean,Mathlib/Analysis/BoxIntegral/Box/SubboxInduction.lean,Mathlib/Topology/Algebra/Order/Field.lean,Mathlib/Topology/Order/Basic.lean	4	3	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	205-75861 6 months ago	205-75864 6 months ago	0-265 4 minutes
23810	b-reinke author:b-reinke	chore(Order/Interval): generalize succ/pred lemmas to partial orders	Many lemmas in `Mathlib/Order/Interval/Set/SuccPred.lean`and `Mathlib/Order/Interval/Finset/SuccPred.lean` also work for partial orders. They are generalized in this PR by introducing different sections for `PartialOrder` and `LinearOrder` assumptions in the respective files. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-order merge-conflict	231/89	Mathlib/Order/Interval/Finset/SuccPred.lean,Mathlib/Order/Interval/Set/SuccPred.lean	2	2	['github-actions', 'leanprover-community-bot-assistant']	nobody	203-52636 6 months ago	203-52638 6 months ago	16-29623 16 days
24285	madvorak author:madvorak	chore(Algebra/*-{Category,Homology}): remove unnecessary universe variables	Discussions: https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Call.20for.20help.3A.20technical.2F.20organisational.20debt/with/513620128 https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Algebra.20and.20.60Type.60/with/513558902 https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Task.2026.3A.20Replace.20Type.20u.20by.20Type.20wherever.20possible/with/513592993 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	542/916	Mathlib/Algebra/AddTorsor/Basic.lean,Mathlib/Algebra/Algebra/Defs.lean,Mathlib/Algebra/Algebra/Equiv.lean,Mathlib/Algebra/Algebra/Field.lean,Mathlib/Algebra/Algebra/Hom.lean,Mathlib/Algebra/Algebra/Operations.lean,Mathlib/Algebra/Algebra/Spectrum/Basic.lean,Mathlib/Algebra/Algebra/Subalgebra/Lattice.lean,Mathlib/Algebra/Algebra/Subalgebra/Tower.lean,Mathlib/Algebra/Algebra/Tower.lean,Mathlib/Algebra/Central/Basic.lean,Mathlib/Algebra/Central/Defs.lean,Mathlib/Algebra/Central/TensorProduct.lean,Mathlib/Algebra/CharP/Pi.lean,Mathlib/Algebra/CharP/Quotient.lean,Mathlib/Algebra/CharP/Subring.lean,Mathlib/Algebra/DirectSum/Algebra.lean,Mathlib/Algebra/DirectSum/Basic.lean,Mathlib/Algebra/DirectSum/Finsupp.lean,Mathlib/Algebra/DirectSum/Module.lean,Mathlib/Algebra/EuclideanDomain/Basic.lean,Mathlib/Algebra/EuclideanDomain/Defs.lean,Mathlib/Algebra/Field/Basic.lean,Mathlib/Algebra/Field/Defs.lean,Mathlib/Algebra/Field/IsField.lean,Mathlib/Algebra/Field/MinimalAxioms.lean,Mathlib/Algebra/Field/Subfield/Basic.lean,Mathlib/Algebra/Field/Subfield/Defs.lean,Mathlib/Algebra/FreeNonUnitalNonAssocAlgebra.lean,Mathlib/Algebra/Group/Conj.lean,Mathlib/Algebra/Group/Defs.lean,Mathlib/Algebra/Group/Equiv/Finite.lean,Mathlib/Algebra/Group/Ext.lean,Mathlib/Algebra/Group/Hom/End.lean,Mathlib/Algebra/Group/Hom/Instances.lean,Mathlib/Algebra/Group/Invertible/Basic.lean,Mathlib/Algebra/Group/Invertible/Defs.lean,Mathlib/Algebra/Group/Pi/Basic.lean,Mathlib/Algebra/Group/Pi/Lemmas.lean,Mathlib/Algebra/Group/TypeTags/Basic.lean,Mathlib/Algebra/Group/TypeTags/Finite.lean,Mathlib/Algebra/Group/TypeTags/Hom.lean,Mathlib/Algebra/Group/Units/Basic.lean,Mathlib/Algebra/Group/Units/Defs.lean,Mathlib/Algebra/Group/Units/Hom.lean,Mathlib/Algebra/Group/WithOne/Basic.lean,Mathlib/Algebra/Group/WithOne/Defs.lean,Mathlib/Algebra/GroupWithZero/Action/Pi.lean,Mathlib/Algebra/GroupWithZero/Defs.lean,Mathlib/Algebra/GroupWithZero/Invertible.lean,Mathlib/Algebra/GroupWithZero/NeZero.lean,Mathlib/Algebra/Lie/Abelian.lean,Mathlib/Algebra/Lie/Basic.lean,Mathlib/Algebra/Lie/CartanMatrix.lean,Mathlib/Algebra/Lie/CartanSubalgebra.lean,Mathlib/Algebra/Lie/Character.lean,Mathlib/Algebra/Lie/Classical.lean,Mathlib/Algebra/Lie/DirectSum.lean,Mathlib/Algebra/Lie/Free.lean,Mathlib/Algebra/Lie/Ideal.lean,Mathlib/Algebra/Lie/IdealOperations.lean,Mathlib/Algebra/Lie/Matrix.lean,Mathlib/Algebra/Lie/Nilpotent.lean,Mathlib/Algebra/Lie/NonUnitalNonAssocAlgebra.lean,Mathlib/Algebra/Lie/OfAssociative.lean,Mathlib/Algebra/Lie/Quotient.lean,Mathlib/Algebra/Lie/SkewAdjoint.lean,Mathlib/Algebra/Lie/Solvable.lean,Mathlib/Algebra/Lie/Subalgebra.lean,Mathlib/Algebra/Lie/Submodule.lean,Mathlib/Algebra/Lie/TensorProduct.lean,Mathlib/Algebra/Lie/UniversalEnveloping.lean,Mathlib/Algebra/Module/Basic.lean,Mathlib/Algebra/Module/CharacterModule.lean,Mathlib/Algebra/Module/DedekindDomain.lean,Mathlib/Algebra/Module/Defs.lean,Mathlib/Algebra/Module/End.lean,Mathlib/Algebra/Module/Equiv/Opposite.lean,Mathlib/Algebra/Module/Lattice.lean,Mathlib/Algebra/Module/LinearMap/Basic.lean,Mathlib/Algebra/Module/LinearMap/Defs.lean,Mathlib/Algebra/Module/LinearMap/End.lean,Mathlib/Algebra/Module/LocalizedModule/Basic.lean,Mathlib/Algebra/Module/MinimalAxioms.lean,Mathlib/Algebra/Module/NatInt.lean,Mathlib/Algebra/Module/Opposite.lean,Mathlib/Algebra/Module/Pi.lean,Mathlib/Algebra/Module/Presentation/Differentials.lean,Mathlib/Algebra/Module/Presentation/Tensor.lean,Mathlib/Algebra/Module/Rat.lean,Mathlib/Algebra/Module/RingHom.lean,Mathlib/Algebra/Module/Submodule/Basic.lean,Mathlib/Algebra/Module/Torsion.lean,Mathlib/Algebra/MonoidAlgebra/Basic.lean,Mathlib/Algebra/MonoidAlgebra/Defs.lean,Mathlib/Algebra/MonoidAlgebra/Support.lean,Mathlib/Algebra/MvPolynomial/Basic.lean,Mathlib/Algebra/MvPolynomial/CommRing.lean,Mathlib/Algebra/MvPolynomial/Degrees.lean,Mathlib/Algebra/MvPolynomial/Equiv.lean	182	22	['erdOne', 'github-actions', 'leanprover-bot', 'leanprover-community-bot-assistant', 'madvorak', 'mattrobball']	nobody	203-41333 6 months ago	203-41334 6 months ago	2-12022 2 days
24354	grunweg author:grunweg	chore(HasFiniteIntegral): rename three lemmas	Discovered in #24343. --- - [ ] depends on: #24343 (to avoid merge conflicts) [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-measure-probability merge-conflict	108/30	Mathlib/MeasureTheory/Function/L1Space/HasFiniteIntegral.lean	1	3	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	198-45737 6 months ago	198-45738 6 months ago	0-4604 1 hour
13649	FR-vdash-bot author:FR-vdash-bot	chore: redefine `Nat.div2` `Nat.bodd`	The new definitions are faster than the old ones. `Nat.binaryRec` will be moved to batteries (https://github.com/leanprover-community/batteries/pull/799) or core (https://github.com/leanprover/lean4/pull/3756), so relevant contents are moved to a new file temporarily. --- - [x] depends on: #15567 - [x] depends on: #19666 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict	63/88	Mathlib/Computability/Primrec.lean,Mathlib/Data/Int/Bitwise.lean,Mathlib/Data/Nat/Bits.lean,Mathlib/Data/Nat/Bitwise.lean,Mathlib/Data/Nat/Size.lean,Mathlib/Logic/Denumerable.lean,Mathlib/Logic/Encodable/Basic.lean,Mathlib/Logic/Equiv/Nat.lean	8	15	['FR-vdash-bot', 'digama0', 'eric-wieser', 'github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'urkud']	digama0 assignee:digama0	195-24883 6 months ago	195-24885 6 months ago	87-51692 87 days
4979	mhk119 author:mhk119	doc(Data/Nat/Bitblast): initial commit	Initial commit of Bitblast.lean where we prove equivalence of bitblast unsigned less than and bitblast addition. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data merge-conflict	202/4	Mathlib/Data/Bool/Basic.lean,Mathlib/Data/Nat/Bitwise.lean,Mathlib/Data/Nat/Pow.lean	3	49	['ChrisHughes24', 'digama0', 'goens', 'grunweg', 'j-loreaux', 'kim-em', 'mhk119']	nobody	194-83118 6 months ago	194-83118 6 months ago	7-68358 7 days
23546	JovanGerb author:JovanGerb	feat(LinearAlgebra/AffineSpace/AffineSubspace): rename `AffineSubspace.mk'` to `Submodule.shift`	In addition to renaming, I've refactored the code a bit: - `mem_mk'_iff_vsub_mem` was obsolete since it was the same as `mem_mk'`, so I removed it (this is due to a change in the definition I made recently) - I added a nonempty instance for `shift` - I added a simp lemma that `shift` isn't equal to `⊥` (the empty affine subspace). I need this for the next point. - Edit: I'll leave this for a later PR. ~I proved a simp lemma that a `shift` is parallel to a `shift` if and only if the linear subspaces are the same.~ - I renamed `mk'_eq` to `shift_direction_eq_self `. - I renamed `eq_or_eq_secondInter_of_mem_mk'_span_singleton_iff_mem` to `eq_or_eq_secondInter_iff_mem_of_mem_shift_span_singleton`. I think it is better to put the `of_mem_mk'_span_singleton` at the end of the name. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-euclidean-geometry merge-conflict	128/99	Mathlib/Algebra/Module/ZLattice/Basic.lean,Mathlib/Geometry/Euclidean/Basic.lean,Mathlib/Geometry/Euclidean/MongePoint.lean,Mathlib/Geometry/Euclidean/PerpBisector.lean,Mathlib/Geometry/Euclidean/Sphere/SecondInter.lean,Mathlib/Geometry/Euclidean/Sphere/Tangent.lean,Mathlib/LinearAlgebra/AffineSpace/AffineSubspace/Defs.lean	7	4	['JovanGerb', 'github-actions', 'leanprover-community-bot-assistant']	nobody	193-57865 6 months ago	193-57866 6 months ago	26-25420 26 days
22837	joneugster author:joneugster	feat(Data/Set/Basic): add subset_iff and not_mem_subset_iff	Add `Set.subset_iff` for consistent API with `Finset.subset_iff`. Add `Set.not_mem_subset_iff` and `Finset.not_mem_subset_iff`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-set-theory t-data merge-conflict	9/0	Mathlib/Data/Finset/Defs.lean,Mathlib/Data/Set/Basic.lean	2	4	['Ruben-VandeVelde', 'github-actions', 'joneugster', 'leanprover-community-bot-assistant']	nobody	172-60865 5 months ago	172-60867 5 months ago	30-35190 30 days
21476	grunweg author:grunweg	feat(lint-style): enable running on downstream projects	Enable lint-style to run on downstream projects, by making the following modifications: - allow passing an explicit list of libraries to lint: if nothing is passed, it lints `Mathlib`, `Archive` and `Counterexamples` (as before); otherwise, it lints precisely the passed modules - only check init imports, undocumented scripts and the errors from `lint-style.py` when linting Mathlib - make the style exceptions file configurable and optional: using the `nolints-file` flag, the exceptions file can be configured. If the flag is omitted, we try to find a file at `scripts/nolints-style.txt` --- and otherwise proceed with no style exceptions. This means mathlib can continue unchanged, and downstream projects can either add an explicit exceptions file, or proceed without any exceptions. After this PR, one should be able to run lint-style on a downstream project by `lake exe lint-style ProjectName`. Prompted by [this zulip discussion](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/lint-style.20for.20downstream.20libraries). --- - [ ] depends on: #24570 - [ ] depends on: #24953 (I did not test the last part.) [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-linter merge-conflict	58/19	Mathlib/Tactic/Linter/TextBased.lean,scripts/lint-style.lean	2	19	['Vierkantor', 'adomani', 'github-actions', 'grunweg', 'joneugster', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	joneugster assignee:joneugster	171-66353 5 months ago	171-66356 5 months ago	43-17409 43 days
23349	BGuillemet author:BGuillemet	feat: add LocallyLipschitzOn.lipschitzOnWith_of_isCompact and two small lemmas about Lipschitz functions	Main feat (in Mathlib/Topology/EMetricSpace/Basic.lean): if a function `f` from an extended pseudometric space to a pseudometric space is locally Lipschitz on a compact subset `s`, then `f` is Lipschitz on `s`. The theorem is true only when the codomain of `f` is a pseudometric space, so it needs imports from Mathlib/Topology/MetricSpace. Other small feat (in Mathlib/Analysis/Calculus/ContDiff/RCLike.lean): a function that is continuously differentiable on an open subset is locally Lipschitz on this subset. --- - [ ] depends on: #22890 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import new-contributor t-topology merge-conflict	59/4	Mathlib/Analysis/Calculus/ContDiff/RCLike.lean,Mathlib/Topology/EMetricSpace/Lipschitz.lean	2	4	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	PatrickMassot assignee:PatrickMassot	170-48083 5 months ago	170-48085 5 months ago	35-30364 35 days
21182	joneugster author:joneugster	fix(Util/CountHeartbeats): move elaboration in #count_heartbeats inside a namespace	Currently the `#count_heartbeat` linter reported the heartbeats until it concluded `error: [declaration] has already been declared` instead of re-elaborating the declaration. --- [Zulip report](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/count_heartbeats.20for.20all.20declarations.20in.20a.20file.3F/near/496303652) [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-meta merge-conflict	72/5	Mathlib/Util/CountHeartbeats.lean,MathlibTest/CountHeartbeats.lean	2	17	['adomani', 'github-actions', 'joneugster', 'leanprover-community-bot-assistant', 'mathlib-bors']	adomani assignee:adomani	163-76831 5 months ago	163-76832 5 months ago	64-19141 64 days
25340	dupuisf author:dupuisf	chore(Analysis/Convex): move files pertaining to convex/concave functions to their own folder	This PR creates a new folder under `Analysis/Convex` called `Analysis/Convex/Function`, which includes files that are mostly or entirely about convex/concave functions (as opposed to convex sets). --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-convex-geometry merge-conflict	4264/4155	Mathlib.lean,Mathlib/Analysis/Convex/Continuous.lean,Mathlib/Analysis/Convex/Deriv.lean,Mathlib/Analysis/Convex/Exposed.lean,Mathlib/Analysis/Convex/Extrema.lean,Mathlib/Analysis/Convex/Function.lean,Mathlib/Analysis/Convex/Function/Basic.lean,Mathlib/Analysis/Convex/Function/Continuous.lean,Mathlib/Analysis/Convex/Function/Deriv.lean,Mathlib/Analysis/Convex/Function/Extrema.lean,Mathlib/Analysis/Convex/Function/Integral.lean,Mathlib/Analysis/Convex/Function/Jensen.lean,Mathlib/Analysis/Convex/Function/Mul.lean,Mathlib/Analysis/Convex/Function/Piecewise.lean,Mathlib/Analysis/Convex/Function/Quasiconvex.lean,Mathlib/Analysis/Convex/Function/Slope.lean,Mathlib/Analysis/Convex/Function/Strong.lean,Mathlib/Analysis/Convex/Integral.lean,Mathlib/Analysis/Convex/Jensen.lean,Mathlib/Analysis/Convex/Mul.lean,Mathlib/Analysis/Convex/Piecewise.lean,Mathlib/Analysis/Convex/Quasiconvex.lean,Mathlib/Analysis/Convex/Slope.lean,Mathlib/Analysis/Convex/SpecificFunctions/Basic.lean,Mathlib/Analysis/Convex/SpecificFunctions/Deriv.lean,Mathlib/Analysis/Convex/Strong.lean,Mathlib/Analysis/MeanInequalities.lean,Mathlib/Analysis/MeanInequalitiesPow.lean,Mathlib/Analysis/Normed/Module/Convex.lean,Mathlib/Analysis/Seminorm.lean,Mathlib/Analysis/SpecialFunctions/Log/NegMulLog.lean,Mathlib/Analysis/SpecialFunctions/Pochhammer.lean,Mathlib/MeasureTheory/Measure/Decomposition/IntegralRNDeriv.lean,Mathlib/NumberTheory/Harmonic/GammaDeriv.lean	34	2	['github-actions', 'leanprover-community-bot-assistant']	nobody	159-70910 5 months ago	159-70912 5 months ago	6-40169 6 days
18441	ADedecker author:ADedecker	refactor(AdicTopology): use new API for algebraic filter bases, and factor some code	--- - [x] depends on: #18437 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra t-topology merge-conflict label:t-algebra$	847/159	Mathlib.lean,Mathlib/Topology/Algebra/FilterBasis.lean,Mathlib/Topology/Algebra/FilterBasisNew.lean,Mathlib/Topology/Algebra/Nonarchimedean/AdicTopology.lean,Mathlib/Topology/Algebra/Nonarchimedean/Bases.lean,Mathlib/Topology/Algebra/Nonarchimedean/BasesNew.lean	6	3	['ADedecker', 'github-actions', 'mathlib4-dependent-issues-bot']	nobody	147-62651 4 months ago	147-62653 4 months ago	0-679 11 minutes
18439	ADedecker author:ADedecker	refactor: use new algebraic filter bases API in `FiniteAdeleRing`	--- - [x] depends on: #18437 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra t-topology merge-conflict label:t-algebra$	699/21	Mathlib.lean,Mathlib/RingTheory/DedekindDomain/FiniteAdeleRing.lean,Mathlib/Topology/Algebra/FilterBasis.lean,Mathlib/Topology/Algebra/FilterBasisNew.lean,Mathlib/Topology/Algebra/Nonarchimedean/Bases.lean,Mathlib/Topology/Algebra/Nonarchimedean/BasesNew.lean	6	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	147-62649 4 months ago	147-62651 4 months ago	0-619 10 minutes
18438	ADedecker author:ADedecker	refactor: adapt `KrullTopology` to the new algebraic filter bases API	--- - [x] depends on: #18437 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra t-topology merge-conflict label:t-algebra$	771/168	Mathlib.lean,Mathlib/FieldTheory/KrullTopology.lean,Mathlib/Topology/Algebra/FilterBasis.lean,Mathlib/Topology/Algebra/FilterBasisNew.lean,Mathlib/Topology/Algebra/Nonarchimedean/Bases.lean,Mathlib/Topology/Algebra/Nonarchimedean/BasesNew.lean	6	5	['ADedecker', 'AntoineChambert-Loir', 'github-actions', 'mathlib4-dependent-issues-bot']	nobody	147-62648 4 months ago	147-62649 4 months ago	0-638 10 minutes
13964	pechersky author:pechersky	feat(Data/DigitExpansion): begin defining variant of reals without rationals	Based on a de Bruijn 1976 paper. This file is just the basic definition of a digit expansion. Will be followed up with further constructions. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data merge-conflict	518/0	Mathlib.lean,Mathlib/Data/DigitExpansion/Defs.lean,docs/references.bib	3	11	['eric-wieser', 'github-actions', 'kim-em', 'pechersky']	dupuisf assignee:dupuisf	144-44939 4 months ago	382-71155 1 year ago	129-57991 129 days
16074	Rida-Hamadani author:Rida-Hamadani	feat: combinatorial maps and planar graphs	We define combinatorial maps, then we define planar graph using combinatorial maps. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-combinatorics merge-conflict	243/0	Mathlib.lean,Mathlib/Combinatorics/SimpleGraph/Planar.lean,Mathlib/Data/CombinatorialMap.lean	3	28	['Parcly-Taxel', 'Rida-Hamadani', 'github-actions', 'lambda-fairy', 'leanprover-community-bot-assistant']	kmill assignee:kmill	132-10514 4 months ago	132-10515 4 months ago	72-51453 72 days
24823	eric-wieser author:eric-wieser	refactor: add `hom` lemmas for the `MonoidalCategory` structure on `ModuleCat`	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	148/164	Mathlib/Algebra/Category/FGModuleCat/Basic.lean,Mathlib/Algebra/Category/ModuleCat/Adjunctions.lean,Mathlib/Algebra/Category/ModuleCat/Monoidal/Basic.lean,Mathlib/Algebra/Category/ModuleCat/Monoidal/Closed.lean,Mathlib/Algebra/Category/ModuleCat/Monoidal/Symmetric.lean,Mathlib/Algebra/Category/ModuleCat/Presheaf/Free.lean,Mathlib/Algebra/Category/ModuleCat/Presheaf/Generator.lean,Mathlib/Algebra/Category/ModuleCat/Presheaf/Monoidal.lean,Mathlib/CategoryTheory/Monoidal/Internal/Module.lean,Mathlib/RepresentationTheory/Coinvariants.lean,Mathlib/RepresentationTheory/Rep.lean	11	21	['101damnations', 'YaelDillies', 'eric-wieser', 'github-actions', 'joelriou', 'kbuzzard', 'leanprover-community-bot-assistant']	101damnations assignee:101damnations	132-9599 4 months ago	132-9599 4 months ago	43-42841 43 days
25071	erdOne author:erdOne	feat(EllipticCurve): basic API for singular cubics	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebraic-geometry merge-conflict	320/0	Mathlib.lean,Mathlib/AlgebraicGeometry/EllipticCurve/Singular/Basic.lean,Mathlib/AlgebraicGeometry/EllipticCurve/VariableChange.lean	3	35	['Multramate', 'acmepjz', 'erdOne', 'github-actions', 'leanprover-community-bot-assistant']	nobody	132-9353 4 months ago	132-9354 4 months ago	45-4961 45 days
25283	Brian-Nugent author:Brian-Nugent	feat: regular local rings	Adds regular local rings and proves they are integral domains. --- - [ ] depends on: #25280 - [ ] depends on: #25282 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra merge-conflict label:t-algebra$	871/0	.vscode/settings.json,Mathlib.lean,Mathlib/RingTheory/EmbeddingDimension.lean,Mathlib/RingTheory/LocalRingDimension.lean,Mathlib/RingTheory/RegularLocalRing.lean	5	6	['Brian-Nugent', 'github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'yuanyi-350']	nobody	132-9346 4 months ago	132-9346 4 months ago	11-84822 11 days
25573	JovanGerb author:JovanGerb	feat: define `∃ x > y, ...` notation to mean `∃ x, y < x ∧ ...`	This PR changes the elaboration of the binders `∃ x > y,` and `∀ x > y,` to use `<` instead of `>`, because we want to avoid working with `>` as much as possible (and similarly for `≥` vs `≤` ). The advantage is that we don't need to worry about rewriting with lemmas like `gt_iff_lt`. The disadvantage is that people might find this confusing. [#mathlib4 > naming convention for ≤ and < @ 💬](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/naming.20convention.20for.20.E2.89.A4.20and.20.3C/near/522910464) The main changes are in `Mathlib.Init`, `Mathlib.Util.Delaborators` and `MathlibTest.delaborators`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-meta merge-conflict	59/52	Counterexamples/DiscreteTopologyNonDiscreteUniformity.lean,Mathlib/Algebra/Order/Monoid/Canonical/Defs.lean,Mathlib/Analysis/Analytic/Basic.lean,Mathlib/Analysis/BoxIntegral/Integrability.lean,Mathlib/Analysis/Calculus/UniformLimitsDeriv.lean,Mathlib/Analysis/Complex/Liouville.lean,Mathlib/Analysis/Complex/OpenMapping.lean,Mathlib/Analysis/Fourier/PoissonSummation.lean,Mathlib/Analysis/MellinTransform.lean,Mathlib/Analysis/Normed/Operator/Banach.lean,Mathlib/Dynamics/Ergodic/Conservative.lean,Mathlib/Dynamics/PeriodicPts/Defs.lean,Mathlib/Geometry/Manifold/IntegralCurve/ExistUnique.lean,Mathlib/Init.lean,Mathlib/MeasureTheory/Covering/LiminfLimsup.lean,Mathlib/MeasureTheory/Function/ConvergenceInMeasure.lean,Mathlib/MeasureTheory/Function/Egorov.lean,Mathlib/MeasureTheory/Function/StronglyMeasurable/Basic.lean,Mathlib/MeasureTheory/Integral/DivergenceTheorem.lean,Mathlib/MeasureTheory/Integral/Layercake.lean,Mathlib/NumberTheory/LSeries/SumCoeff.lean,Mathlib/Order/Filter/AtTopBot/Finite.lean,Mathlib/RingTheory/RootsOfUnity/PrimitiveRoots.lean,Mathlib/RingTheory/Valuation/Basic.lean,Mathlib/Topology/CWComplex/Classical/Finite.lean,Mathlib/Topology/ContinuousMap/Ideals.lean,Mathlib/Topology/EMetricSpace/Defs.lean,Mathlib/Topology/EMetricSpace/Paracompact.lean,Mathlib/Topology/LocallyFinite.lean,Mathlib/Topology/MetricSpace/Ultra/Basic.lean,Mathlib/Util/Delaborators.lean,MathlibTest/delaborators.lean	32	2	['github-actions', 'leanprover-community-bot-assistant']	nobody	132-9334 4 months ago	132-9335 4 months ago	26-17604 26 days
25988	Multramate author:Multramate	refactor(AlgebraicGeometry/EllipticCurve/*): replace Fin 3 with products	This PR continues the work from #24593. Original PR: https://github.com/leanprover-community/mathlib4/pull/24593	t-algebraic-geometry merge-conflict	1000/1022	Mathlib/AlgebraicGeometry/EllipticCurve/Jacobian/Basic.lean,Mathlib/AlgebraicGeometry/EllipticCurve/Jacobian/Formula.lean,Mathlib/AlgebraicGeometry/EllipticCurve/Jacobian/Point.lean,Mathlib/AlgebraicGeometry/EllipticCurve/Projective/Basic.lean,Mathlib/AlgebraicGeometry/EllipticCurve/Projective/Formula.lean,Mathlib/AlgebraicGeometry/EllipticCurve/Projective/Point.lean	6	3	['Multramate', 'github-actions', 'leanprover-community-bot-assistant']	nobody	132-9041 4 months ago	132-9041 4 months ago	18-21880 18 days
26012	linesthatinterlace author:linesthatinterlace	feat: Low-level derivatives of lifts on `OneHom`, `MulHom` and `MonoidHom`	This PR continues the work from #25290. Original PR: https://github.com/leanprover-community/mathlib4/pull/25290	migrated-from-branch t-algebra merge-conflict label:t-algebra$	785/34	Mathlib/Algebra/Group/Equiv/Basic.lean,Mathlib/Algebra/Group/Hom/Basic.lean,Mathlib/Algebra/Group/Hom/Defs.lean,Mathlib/Algebra/Ring/Hom/Basic.lean,Mathlib/Algebra/Ring/Hom/Defs.lean	5	3	['github-actions', 'leanprover-community-bot-assistant', 'linesthatinterlace']	nobody	132-9036 4 months ago	132-9037 4 months ago	17-68773 17 days
7596	alreadydone author:alreadydone	feat: covering maps from properly discontinuous actions and discrete subgroups	--- - [x] depends on: #23236 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	file-removed t-topology merge-conflict	350/21	Mathlib.lean,Mathlib/Analysis/SpecialFunctions/Complex/Circle.lean,Mathlib/Topology/Algebra/ConstMulAction.lean,Mathlib/Topology/Algebra/Group/Pointwise.lean,Mathlib/Topology/Covering/AddCircle.lean,Mathlib/Topology/Covering/Basic.lean,Mathlib/Topology/Covering/Galois.lean,Mathlib/Topology/Homotopy/Lifting.lean,Mathlib/Topology/Instances/AddCircle/Defs.lean	9	18	['ADedecker', 'alreadydone', 'digama0', 'github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'tb65536']	nobody	131-47617 4 months ago	131-47618 4 months ago	73-67280 73 days
24405	mcdoll author:mcdoll	refactor(Topology/Algebra/Module/WeakDual): Clean up	- Move `Dual` and `dualPairing` lower in the import-hierachy - deduplicate `dualPairing` - Make `WeakDual` and `WeakSpace` reducible --- New version of #11500 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import t-topology merge-conflict	146/162	Mathlib.lean,Mathlib/Analysis/Fourier/RiemannLebesgueLemma.lean,Mathlib/Analysis/InnerProductSpace/Adjoint.lean,Mathlib/Analysis/InnerProductSpace/Dual.lean,Mathlib/Analysis/LocallyConvex/WeakSpace.lean,Mathlib/Analysis/Normed/Module/Dual.lean,Mathlib/Analysis/Normed/Module/WeakDual.lean,Mathlib/Analysis/VonNeumannAlgebra/Basic.lean,Mathlib/MeasureTheory/Function/AEEqOfIntegral.lean,Mathlib/MeasureTheory/Measure/FiniteMeasure.lean,Mathlib/Topology/Algebra/Module/Dual.lean,Mathlib/Topology/Algebra/Module/WeakDual.lean,docs/overview.yaml,docs/undergrad.yaml	14	2	['github-actions', 'leanprover-community-bot-assistant']	nobody	130-60870 4 months ago	130-60871 4 months ago	69-52361 69 days
26067	mapehe author:mapehe	feat(Topology/StoneCech): exists_continuous_surjection_from_StoneCech_to_dense_range	This lemma formalises the following version of the maximality property of the Stone–Čech compactification: If `f : α → β` is a continuous map from a topological space `α` to a Hausdorff space `β` with dense range, then there exists a continuous surjection from `StoneCech α` to `β` extending `f`. In particular, `StoneCech α` is the “largest” compact Hausdorff space into which `α` densely embeds, in the sense that any other such space is a continuous image of it. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology merge-conflict	18/0	Mathlib/Topology/StoneCech.lean	1	2	['github-actions', 'leanprover-community-bot-assistant']	nobody	128-76819 4 months ago	128-76819 4 months ago	20-8582 20 days
24096	plp127 author:plp127	feat(Topology): Completely Regular Space iff Uniformizable	Proves that `CompletelyRegularSpace`s are uniformizable and that `UniformSpace`s are completely regular. --- - [x] depends on: #24179 - [x] depends on: #24173 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology merge-conflict	339/1	Mathlib.lean,Mathlib/Topology/Bases.lean,Mathlib/Topology/UniformSpace/Basic.lean,Mathlib/Topology/UniformSpace/Defs.lean,Mathlib/Topology/UniformSpace/Uniformizable.lean	5	10	['alreadydone', 'github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'plp127']	nobody	125-50121 4 months ago	126-9138 4 months ago	2-8297 2 days
26608	vihdzp author:vihdzp	feat(SetTheory/Cardinal/Aleph): `o.card ≤ ℵ_ o` and variants	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-set-theory merge-conflict	24/0	Mathlib/SetTheory/Cardinal/Aleph.lean	1	3	['github-actions', 'kckennylau', 'leanprover-community-bot-assistant']	nobody	111-40094 3 months ago	111-40095 3 months ago	23-63406 23 days
20719	gio256 author:gio256	feat(AlgebraicTopology): delaborators for truncated simplicial notations	We add delaborators for the following notations, introduced in #20688: - `⦋m⦌ₙ`, which denotes the `m`-dimensional simplex in the `n`-truncated simplex category. - `X _⦋m⦌ₙ`, which denotes the `m`-th term of an `n`-truncated simplicial object `X`. - `X ^⦋m⦌ₙ`, which denotes the `m`-th term of an `n`-truncated cosimplicial object `X`. If `pp.proofs` is set to `true`, we also pretty-print the proof `p : m ≤ n` for all three notations as `⦋m, p⦌ₙ`, `X _⦋m, p⦌ₙ`, and `X ^⦋m, p⦌ₙ`, respectively. Credit to @kmill for one piece of code and much metaprogramming inspiration. --- - [x] depends on: #20688 - [x] depends on: #23018 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebraic-topology infinity-cosmos t-meta merge-conflict	525/33	Mathlib.lean,Mathlib/AlgebraicTopology/SimplexCategory/Basic.lean,Mathlib/AlgebraicTopology/SimplexCategory/Defs.lean,Mathlib/AlgebraicTopology/SimplicialObject/Basic.lean,Mathlib/Tactic.lean,Mathlib/Tactic/SimplexCategory.lean,Mathlib/Util/Superscript.lean,MathlibTest/SimplexCategory.lean,MathlibTest/SimplicialObject.lean,MathlibTest/superscript.lean,scripts/noshake.json	11	23	['eric-wieser', 'gio256', 'github-actions', 'kim-em', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	eric-wieser assignee:eric-wieser	105-67696 3 months ago	105-67696 3 months ago	88-84229 88 days
25238	Hagb author:Hagb	feat(Tactic/ComputeDegree): add support for scalar multiplication with different types	It would be able to deal with `a • (X : R[X])` where `a : S` is in a different type `S` with `[SMulZeroClass S R]`. --- - [x] depends on: #25237 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-meta merge-conflict	17/5	Mathlib/Tactic/ComputeDegree.lean,MathlibTest/ComputeDegree.lean	2	3	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	101-74081 3 months ago	101-74081 3 months ago	38-26044 38 days
11632	mattrobball author:mattrobball	chore(Group/RingTheory.Congruence): make `Quotient`'s reducible	These are essentially wrappers and should not expose any data when made reducible. Their use in constructing typeclass instances makes reducible transparency desirable. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-group-theory merge-conflict	16/35	Mathlib/GroupTheory/Congruence/Basic.lean,Mathlib/RingTheory/Congruence/Basic.lean	2	14	['eric-wieser', 'fpvandoorn', 'github-actions', 'grunweg', 'kmill', 'leanprover-bot', 'mattrobball']	nobody	101-74028 3 months ago	101-74028 3 months ago	2-10495 2 days
9820	jjaassoonn author:jjaassoonn	feat(RingTheory/GradedAlgebra/HomogeneousIdeal): generalize to homogeneous submodule	The definitions, constructions and theorems in `HomogeneousIdeal.lean` are generalized to a homogeneous submodules. So say $R$ is a ring and $M \cong \bigoplus_{i} M_i$ is an $R$-module. Then a homogeneous $R$-submodule of $M$ is an $R$-submodule $N$ such that for all $i$ and $n \in N$, $n_i \in N$. Note that this notion doesn't actually require $R$ to be graded and $M$ is a graded module. But for more interesting lemmas, we do need that $M$ is graded $R$-module. We bake the fact $R$ is graded into the definition of homogeneous submodule, otherwise, `CompleteLattice HomogeneousSubmodule` cannot find the order of synthesis (the proof depends on that $R$ is graded) All definitions/constructions/theorems have a copy for ideals as well, this is to make sure dot notation still works. The motivation of this generalization is graded quotient module --- - [ ] depends on:#18728 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-ring-theory merge-conflict	516/185	Mathlib/Algebra/Module/GradedModule.lean,Mathlib/AlgebraicGeometry/ProjectiveSpectrum/Scheme.lean,Mathlib/AlgebraicGeometry/ProjectiveSpectrum/Topology.lean,Mathlib/RingTheory/GradedAlgebra/Homogeneous/Ideal.lean,Mathlib/RingTheory/GradedAlgebra/Homogeneous/Submodule.lean,Mathlib/RingTheory/GradedAlgebra/Radical.lean,scripts/nolints_prime_decls.txt	7	3	['github-actions', 'leanprover-community-bot-assistant']	nobody	100-76003 3 months ago	100-76003 3 months ago	172-57747 172 days
9339	FMLJohn author:FMLJohn	feat (RingTheory/GradedAlgebra/HomogeneousIdeal): given a finitely generated homogeneous ideal of a graded semiring, construct a finite spanning set for the ideal which only contains homogeneous elements	--- - [ ] depends on: #8187 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-ring-theory merge-conflict	402/4	Mathlib.lean,Mathlib/Algebra/DirectSum/Internal.lean,Mathlib/Algebra/GradedMonoid.lean,Mathlib/Algebra/Module/GradeZeroModule.lean,Mathlib/RingTheory/Finiteness.lean,Mathlib/RingTheory/GradedAlgebra/Basic.lean,Mathlib/RingTheory/GradedAlgebra/HomogeneousIdeal.lean,Mathlib/RingTheory/GradedAlgebra/Noetherian.lean	8	11	['FMLJohn', 'github-actions', 'jjaassoonn', 'leanprover-community-mathlib4-bot']	nobody	100-75996 3 months ago	100-75996 3 months ago	0-0 0 seconds
26200	adomani author:adomani	fix: add label when landrun fails	Adds the `permission-denied` label on PRs that get blocked by landrun. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	CI merge-conflict	68/8	.github/build.in.yml,.github/workflows/bors.yml,.github/workflows/build.yml,.github/workflows/build_fork.yml	4	2	['github-actions', 'mathlib4-merge-conflict-bot']	nobody	100-25034 3 months ago	100-25034 3 months ago	46-52210 46 days
27451	kckennylau author:kckennylau	feat(RingTheory/Valuation): define ball, closed ball, and sphere	From the 2025 Local Class Field Theory Workshop. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-ring-theory merge-conflict	27/0	Mathlib/RingTheory/Valuation/Basic.lean	1	13	['JovanGerb', 'github-actions', 'kckennylau', 'mathlib4-merge-conflict-bot', 'pechersky', 'wwylele']	nobody	94-57537 3 months ago	94-57538 3 months ago	17-52359 17 days
27987	kckennylau author:kckennylau	feat(RingTheory/Valuation): define ball, closed ball, and sphere	--- The pullback PR of #26827 and #27451. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-ring-theory large-import merge-conflict	73/0	Mathlib/RingTheory/Valuation/Basic.lean	1	4	['JovanGerb', 'github-actions', 'kckennylau', 'mathlib4-merge-conflict-bot']	nobody	94-57166 3 months ago	94-57167 3 months ago	6-6455 6 days
27003	eric-wieser author:eric-wieser	chore: use `Simp.ResultQ` more often	Also uses `~q` in place of manual `isDefEq` matching. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-meta merge-conflict	18/22	Mathlib/Tactic/NormNum/Core.lean,Mathlib/Tactic/NormNum/Result.lean,Mathlib/Tactic/ReduceModChar.lean	3	7	['JovanGerb', 'eric-wieser', 'github-actions', 'mathlib4-merge-conflict-bot']	JovanGerb assignee:JovanGerb	92-71790 3 months ago	92-71791 3 months ago	32-70098 32 days
25483	VTrelat author:VTrelat	chore(Data/Set/Prod, SetTheory/ZFC/Basic): add theorem prod_subset_of_prod and extend ZFC model	Required by @eric-wieser in #24281 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data new-contributor merge-conflict	103/0	Mathlib/Data/Set/Prod.lean,Mathlib/SetTheory/ZFC/Basic.lean	2	10	['Ruben-VandeVelde', 'VTrelat', 'github-actions', 'leanprover-community-bot-assistant']	nobody	92-61433 3 months ago	132-9340 4 months ago	29-56208 29 days
25401	digama0 author:digama0	feat(Util): SuppressSorry option	See also leanprover/lean4#8611 and [#lean4 > Silent sorry @ 💬](https://leanprover.zulipchat.com/#narrow/channel/270676-lean4/topic/Silent.20sorry/near/503537964). This is a stop-gap solution while leanprover/lean4#8611 is underway, but it works about as well as any other built in option. Hooking declaration elaborators turns out to be a very powerful technique. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-meta merge-conflict	342/0	Mathlib.lean,Mathlib/Util/CommandElabHook.lean,Mathlib/Util/SuppressSorry.lean,MathlibTest/suppressSorry.lean	4	15	['digama0', 'eric-wieser', 'github-actions', 'mathlib4-merge-conflict-bot']	alexjbest assignee:alexjbest	92-26586 3 months ago	92-26586 3 months ago	71-28549 71 days
19097	Vierkantor author:Vierkantor	chore(Algebra.Polynomial): split `Polynomial/Basic.lean` into smaller files	This PR splits `Mathlib.Algebra.Polynomial.Basic` into the following files: * `Polynomial/Defs.lean`: definition and ring structure on `R[X]` * `Polynomial/Module.lean`: module structure on `R[X]` * `Polynomial/Monomial.lean`: merged definition of `monomial`, `X`, `C` into the existing file (this is probably the file you want to import from now on) * `Polynomial/EraseUpdate.lean`: definition of `erase` and `update` * `Polynomial/Sum.lean`: definition of `sum` Initially I added the monomial results to a new file, but ended up merging it with `Monomial.lean` since the two of them merge cleanly. --- - [x] depends on: #28030 (going to resurrect this PR on top of that one later) - [x] depends on: #19095 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	3109/2500	Mathlib.lean,Mathlib/Algebra/BigOperators/Finsupp.lean,Mathlib/Algebra/MonoidAlgebra/Basic.lean,Mathlib/Algebra/MonoidAlgebra/Defs.lean,Mathlib/Algebra/MonoidAlgebra/Division.lean,Mathlib/Algebra/MonoidAlgebra/Lift.lean,Mathlib/Algebra/MonoidAlgebra/MapDomain.lean,Mathlib/Algebra/MonoidAlgebra/Module.lean,Mathlib/Algebra/MonoidAlgebra/Opposite.lean,Mathlib/Algebra/MonoidAlgebra/Support.lean,Mathlib/Algebra/Polynomial/Basic.lean,Mathlib/Algebra/Polynomial/Cardinal.lean,Mathlib/Algebra/Polynomial/Coeff.lean,Mathlib/Algebra/Polynomial/Defs.lean,Mathlib/Algebra/Polynomial/Degree/Definitions.lean,Mathlib/Algebra/Polynomial/Degree/TrailingDegree.lean,Mathlib/Algebra/Polynomial/EraseUpdate.lean,Mathlib/Algebra/Polynomial/Eval/Defs.lean,Mathlib/Algebra/Polynomial/Eval/Degree.lean,Mathlib/Algebra/Polynomial/Module.lean,Mathlib/Algebra/Polynomial/Monomial.lean,Mathlib/Algebra/Polynomial/Sum.lean,Mathlib/Data/Finsupp/Basic.lean,Mathlib/Data/Finsupp/Defs.lean,Mathlib/Data/Finsupp/Ext.lean,Mathlib/Data/Finsupp/Fintype.lean,Mathlib/Data/Finsupp/Indicator.lean,Mathlib/Data/Finsupp/Notation.lean,Mathlib/Data/Finsupp/Pointwise.lean,Mathlib/Data/Finsupp/SMulWithZero.lean,Mathlib/Data/Finsupp/Single.lean,Mathlib/Data/List/ToFinsupp.lean,Mathlib/LinearAlgebra/Matrix/Charpoly/Eigs.lean,Mathlib/RingTheory/KrullDimension/Basic.lean,Mathlib/RingTheory/Polynomial/Opposites.lean,Mathlib/RingTheory/PowerSeries/Basic.lean,Mathlib/Tactic/ExtractGoal.lean,MathlibTest/Polynomial.lean,MathlibTest/instance_diamonds.lean,scripts/noshake.json	40	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	86-69587 2 months ago	92-62372 3 months ago	0-0 0 seconds
28622	alreadydone author:alreadydone	chore(Mathlib): replace `=>` by `↦`	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict	51792/51792	Mathlib/Algebra/AddTorsor/Basic.lean,Mathlib/Algebra/AddTorsor/Defs.lean,Mathlib/Algebra/Algebra/Basic.lean,Mathlib/Algebra/Algebra/Bilinear.lean,Mathlib/Algebra/Algebra/Defs.lean,Mathlib/Algebra/Algebra/Equiv.lean,Mathlib/Algebra/Algebra/Hom.lean,Mathlib/Algebra/Algebra/Hom/Rat.lean,Mathlib/Algebra/Algebra/NonUnitalHom.lean,Mathlib/Algebra/Algebra/NonUnitalSubalgebra.lean,Mathlib/Algebra/Algebra/Operations.lean,Mathlib/Algebra/Algebra/Opposite.lean,Mathlib/Algebra/Algebra/Prod.lean,Mathlib/Algebra/Algebra/Rat.lean,Mathlib/Algebra/Algebra/Spectrum/Basic.lean,Mathlib/Algebra/Algebra/Spectrum/Pi.lean,Mathlib/Algebra/Algebra/Spectrum/Quasispectrum.lean,Mathlib/Algebra/Algebra/Subalgebra/Basic.lean,Mathlib/Algebra/Algebra/Subalgebra/Centralizer.lean,Mathlib/Algebra/Algebra/Subalgebra/Directed.lean,Mathlib/Algebra/Algebra/Subalgebra/IsSimpleOrder.lean,Mathlib/Algebra/Algebra/Subalgebra/Lattice.lean,Mathlib/Algebra/Algebra/Subalgebra/Matrix.lean,Mathlib/Algebra/Algebra/Subalgebra/Operations.lean,Mathlib/Algebra/Algebra/Subalgebra/Pointwise.lean,Mathlib/Algebra/Algebra/Subalgebra/Prod.lean,Mathlib/Algebra/Algebra/Subalgebra/Unitization.lean,Mathlib/Algebra/Algebra/Tower.lean,Mathlib/Algebra/Algebra/TransferInstance.lean,Mathlib/Algebra/Algebra/Unitization.lean,Mathlib/Algebra/Algebra/ZMod.lean,Mathlib/Algebra/AlgebraicCard.lean,Mathlib/Algebra/BigOperators/Associated.lean,Mathlib/Algebra/BigOperators/Expect.lean,Mathlib/Algebra/BigOperators/Fin.lean,Mathlib/Algebra/BigOperators/Finprod.lean,Mathlib/Algebra/BigOperators/Finsupp/Basic.lean,Mathlib/Algebra/BigOperators/Finsupp/Fin.lean,Mathlib/Algebra/BigOperators/Group/Finset/Basic.lean,Mathlib/Algebra/BigOperators/Group/Finset/Defs.lean,Mathlib/Algebra/BigOperators/Group/Finset/Piecewise.lean,Mathlib/Algebra/BigOperators/Group/Finset/Sigma.lean,Mathlib/Algebra/BigOperators/Group/List/Basic.lean,Mathlib/Algebra/BigOperators/Group/List/Defs.lean,Mathlib/Algebra/BigOperators/Group/List/Lemmas.lean,Mathlib/Algebra/BigOperators/Group/Multiset/Basic.lean,Mathlib/Algebra/BigOperators/Group/Multiset/Defs.lean,Mathlib/Algebra/BigOperators/GroupWithZero/Finset.lean,Mathlib/Algebra/BigOperators/Intervals.lean,Mathlib/Algebra/BigOperators/Option.lean,Mathlib/Algebra/BigOperators/Pi.lean,Mathlib/Algebra/BigOperators/Ring/Finset.lean,Mathlib/Algebra/BigOperators/Ring/Multiset.lean,Mathlib/Algebra/Category/AlgCat/Basic.lean,Mathlib/Algebra/Category/AlgCat/Limits.lean,Mathlib/Algebra/Category/AlgCat/Monoidal.lean,Mathlib/Algebra/Category/BialgCat/Basic.lean,Mathlib/Algebra/Category/BoolRing.lean,Mathlib/Algebra/Category/CoalgCat/Basic.lean,Mathlib/Algebra/Category/CoalgCat/ComonEquivalence.lean,Mathlib/Algebra/Category/FGModuleCat/Limits.lean,Mathlib/Algebra/Category/Grp/AB.lean,Mathlib/Algebra/Category/Grp/Adjunctions.lean,Mathlib/Algebra/Category/Grp/Basic.lean,Mathlib/Algebra/Category/Grp/Biproducts.lean,Mathlib/Algebra/Category/Grp/CartesianMonoidal.lean,Mathlib/Algebra/Category/Grp/Colimits.lean,Mathlib/Algebra/Category/Grp/EpiMono.lean,Mathlib/Algebra/Category/Grp/FilteredColimits.lean,Mathlib/Algebra/Category/Grp/Images.lean,Mathlib/Algebra/Category/Grp/Kernels.lean,Mathlib/Algebra/Category/Grp/LargeColimits.lean,Mathlib/Algebra/Category/Grp/LeftExactFunctor.lean,Mathlib/Algebra/Category/Grp/Limits.lean,Mathlib/Algebra/Category/Grp/Preadditive.lean,Mathlib/Algebra/Category/Grp/ZModuleEquivalence.lean,Mathlib/Algebra/Category/Grp/Zero.lean,Mathlib/Algebra/Category/GrpWithZero.lean,Mathlib/Algebra/Category/HopfAlgCat/Basic.lean,Mathlib/Algebra/Category/ModuleCat/Adjunctions.lean,Mathlib/Algebra/Category/ModuleCat/Basic.lean,Mathlib/Algebra/Category/ModuleCat/Biproducts.lean,Mathlib/Algebra/Category/ModuleCat/ChangeOfRings.lean,Mathlib/Algebra/Category/ModuleCat/Colimits.lean,Mathlib/Algebra/Category/ModuleCat/EpiMono.lean,Mathlib/Algebra/Category/ModuleCat/FilteredColimits.lean,Mathlib/Algebra/Category/ModuleCat/Images.lean,Mathlib/Algebra/Category/ModuleCat/Injective.lean,Mathlib/Algebra/Category/ModuleCat/Kernels.lean,Mathlib/Algebra/Category/ModuleCat/Limits.lean,Mathlib/Algebra/Category/ModuleCat/Monoidal/Basic.lean,Mathlib/Algebra/Category/ModuleCat/Monoidal/Closed.lean,Mathlib/Algebra/Category/ModuleCat/Monoidal/Symmetric.lean,Mathlib/Algebra/Category/ModuleCat/Presheaf.lean,Mathlib/Algebra/Category/ModuleCat/Presheaf/Abelian.lean,Mathlib/Algebra/Category/ModuleCat/Presheaf/Colimits.lean,Mathlib/Algebra/Category/ModuleCat/Presheaf/Limits.lean,Mathlib/Algebra/Category/ModuleCat/Presheaf/Pushforward.lean,Mathlib/Algebra/Category/ModuleCat/Presheaf/Sheafify.lean,Mathlib/Algebra/Category/ModuleCat/Products.lean	3838	4	['github-actions', 'mathlib4-merge-conflict-bot']	nobody	86-30066 2 months ago	86-30067 2 months ago	0-83357 23 hours
28532	alreadydone author:alreadydone	chore(Algebra/Ring/Defs): add two classes and extend more	Add the missing `NonAssocComm(Semi)ring` and modify existing classes to `extends` more to remove some manual instances. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	89/70	Mathlib/Algebra/Colimit/DirectLimit.lean,Mathlib/Algebra/Ring/Defs.lean,Mathlib/Analysis/Normed/Unbundled/SpectralNorm.lean,Mathlib/LinearAlgebra/CliffordAlgebra/Basic.lean,Mathlib/NumberTheory/SelbergSieve.lean,Mathlib/RingTheory/Localization/Integral.lean,Mathlib/RingTheory/PowerSeries/GaussNorm.lean,Mathlib/RingTheory/Valuation/Discrete/Basic.lean,Mathlib/Tactic/Ring/Basic.lean,MathlibTest/TCSynth.lean	10	17	['alreadydone', 'eric-wieser', 'github-actions', 'leanprover-bot', 'mathlib4-merge-conflict-bot']	nobody	85-49929 2 months ago	85-49930 2 months ago	2-77063 2 days
28626	alreadydone author:alreadydone	chore(Archive, Counterexamples): replace => by ↦	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict	288/288	Archive/Arithcc.lean,Archive/Examples/IfNormalization/Result.lean,Archive/Examples/IfNormalization/WithoutAesop.lean,Archive/Examples/PropEncodable.lean,Archive/Imo/Imo1959Q1.lean,Archive/Imo/Imo1960Q1.lean,Archive/Imo/Imo1962Q4.lean,Archive/Imo/Imo1972Q5.lean,Archive/Imo/Imo1977Q6.lean,Archive/Imo/Imo1981Q3.lean,Archive/Imo/Imo1987Q1.lean,Archive/Imo/Imo1988Q6.lean,Archive/Imo/Imo1994Q1.lean,Archive/Imo/Imo1998Q2.lean,Archive/Imo/Imo2001Q2.lean,Archive/Imo/Imo2006Q3.lean,Archive/Imo/Imo2006Q5.lean,Archive/Imo/Imo2008Q2.lean,Archive/Imo/Imo2008Q4.lean,Archive/Imo/Imo2011Q3.lean,Archive/Imo/Imo2013Q1.lean,Archive/Imo/Imo2019Q1.lean,Archive/Imo/Imo2024Q5.lean,Archive/MiuLanguage/Basic.lean,Archive/MiuLanguage/DecisionSuf.lean,Archive/OxfordInvariants/Summer2021/Week3P1.lean,Archive/Sensitivity.lean,Archive/Wiedijk100Theorems/AbelRuffini.lean,Archive/Wiedijk100Theorems/AreaOfACircle.lean,Archive/Wiedijk100Theorems/AscendingDescendingSequences.lean,Archive/Wiedijk100Theorems/BallotProblem.lean,Archive/Wiedijk100Theorems/BirthdayProblem.lean,Archive/Wiedijk100Theorems/BuffonsNeedle.lean,Archive/Wiedijk100Theorems/CubingACube.lean,Archive/Wiedijk100Theorems/FriendshipGraphs.lean,Archive/Wiedijk100Theorems/Konigsberg.lean,Archive/Wiedijk100Theorems/Partition.lean,Archive/Wiedijk100Theorems/SumOfPrimeReciprocalsDiverges.lean,Archive/ZagierTwoSquares.lean,Counterexamples/AharoniKorman.lean,Counterexamples/CanonicallyOrderedCommSemiringTwoMul.lean,Counterexamples/CharPZeroNeCharZero.lean,Counterexamples/CliffordAlgebraNotInjective.lean,Counterexamples/DirectSumIsInternal.lean,Counterexamples/GameMultiplication.lean,Counterexamples/Girard.lean,Counterexamples/HomogeneousPrimeNotPrime.lean,Counterexamples/MapFloor.lean,Counterexamples/MonicNonRegular.lean,Counterexamples/Phillips.lean,Counterexamples/Pseudoelement.lean,Counterexamples/QuadraticForm.lean,Counterexamples/SorgenfreyLine.lean,Counterexamples/ZeroDivisorsInAddMonoidAlgebras.lean	54	2	['github-actions', 'mathlib4-merge-conflict-bot']	nobody	84-59192 2 months ago	84-59193 2 months ago	2-48353 2 days
13795	astrainfinita author:astrainfinita	perf(Algebra/{Group, GroupWithZero, Ring}/InjSurj): reduce everything	--- - [ ] depends on: #15192 - [ ] depends on: #15476 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	340/194	Mathlib/Algebra/Equiv/TransferInstance.lean,Mathlib/Algebra/Group/InjSurj.lean,Mathlib/Algebra/GroupWithZero/Action/Defs.lean,Mathlib/Algebra/GroupWithZero/Action/End.lean,Mathlib/Algebra/GroupWithZero/InjSurj.lean,Mathlib/Algebra/Module/Defs.lean,Mathlib/Algebra/Module/RingHom.lean,Mathlib/Algebra/Ring/InjSurj.lean,scripts/noshake.json	9	37	['MichaelStollBayreuth', 'astrainfinita', 'eric-wieser', 'github-actions', 'leanprover-bot', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mattrobball']	nobody	83-65263 2 months ago	212-80268 6 months ago	52-31623 52 days
28150	Equilibris author:Equilibris	chore: clean up proofs typevec proofs	While adding variable universe corecs I found a lot of theorems in typevec that could do with a bit of a clean-up --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data new-contributor merge-conflict	24/26	Mathlib/Data/TypeVec.lean	1	7	['Equilibris', 'alexkeizer', 'github-actions', 'mathlib4-merge-conflict-bot']	nobody	83-26508 2 months ago	83-26509 2 months ago	13-49738 13 days
27403	MoritzBeroRoos author:MoritzBeroRoos	fix: replace probably erroneous usage of ⬝ (with old \cdot) by · (with \centerdot)	Discussion at [zulip](https://leanprover.zulipchat.com/#narrow/channel/270676-lean4/topic/.5Ccdot.20!.3D.20.5Ccenterdot). Currently the abbreviations \cdot and \centerdot resolve to different, with the naked eye nearly undistinguishable symbols (despite the c in cdot surely standing for center..). This pr replaces instances of ⬝ where · was probably meant. All of the replacement is in comments, except for the file bench_summary.lean which is used for priting the github benchmark results. Since this file is about scientific notation of numbers, sure · was meant to be used, not a rectangle. [Related](https://github.com/leanprover-community/mathlib4/pull/27399) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor merge-conflict	195/195	Mathlib/Algebra/ContinuedFractions/Computation/Approximations.lean,Mathlib/Algebra/DirectSum/Idempotents.lean,Mathlib/Algebra/Lie/Derivation/Basic.lean,Mathlib/Algebra/Module/Equiv/Basic.lean,Mathlib/AlgebraicGeometry/EllipticCurve/DivisionPolynomial/Basic.lean,Mathlib/Analysis/Analytic/Constructions.lean,Mathlib/Analysis/CStarAlgebra/CStarMatrix.lean,Mathlib/Analysis/Calculus/ContDiff/Basic.lean,Mathlib/Analysis/Calculus/ContDiff/Bounds.lean,Mathlib/Analysis/Calculus/FDeriv/Symmetric.lean,Mathlib/Analysis/Fourier/FourierTransformDeriv.lean,Mathlib/Analysis/InnerProductSpace/Dual.lean,Mathlib/Analysis/InnerProductSpace/PiL2.lean,Mathlib/Analysis/Normed/Unbundled/InvariantExtension.lean,Mathlib/Analysis/SpecialFunctions/Complex/CircleAddChar.lean,Mathlib/Combinatorics/Configuration.lean,Mathlib/Combinatorics/SimpleGraph/AdjMatrix.lean,Mathlib/Combinatorics/SimpleGraph/LapMatrix.lean,Mathlib/Data/Matrix/Block.lean,Mathlib/Data/Matrix/ConjTranspose.lean,Mathlib/Data/Matrix/Hadamard.lean,Mathlib/Data/Matrix/Mul.lean,Mathlib/Data/Matrix/Notation.lean,Mathlib/Data/Matrix/Reflection.lean,Mathlib/Data/Matrix/RowCol.lean,Mathlib/Data/Matrix/Vec.lean,Mathlib/FieldTheory/PurelyInseparable/PerfectClosure.lean,Mathlib/Geometry/Manifold/GroupLieAlgebra.lean,Mathlib/GroupTheory/Coxeter/Matrix.lean,Mathlib/LinearAlgebra/CrossProduct.lean,Mathlib/LinearAlgebra/Matrix/BilinearForm.lean,Mathlib/LinearAlgebra/Matrix/DotProduct.lean,Mathlib/LinearAlgebra/Matrix/Nondegenerate.lean,Mathlib/LinearAlgebra/Matrix/Orthogonal.lean,Mathlib/LinearAlgebra/Matrix/PosDef.lean,Mathlib/LinearAlgebra/Matrix/SchurComplement.lean,Mathlib/LinearAlgebra/Matrix/SesquilinearForm.lean,Mathlib/LinearAlgebra/Matrix/Trace.lean,Mathlib/LinearAlgebra/Multilinear/Basic.lean,Mathlib/LinearAlgebra/PerfectPairing/Matrix.lean,Mathlib/LinearAlgebra/Projectivization/Constructions.lean,Mathlib/NumberTheory/NumberField/ProductFormula.lean,Mathlib/NumberTheory/SiegelsLemma.lean,Mathlib/RingTheory/DividedPowers/SubDPIdeal.lean,Mathlib/SetTheory/Ordinal/Veblen.lean,Mathlib/Topology/Algebra/Module/Equiv.lean,Mathlib/Topology/Homeomorph/Lemmas.lean,Mathlib/Topology/Instances/Matrix.lean,scripts/bench_summary.lean	49	5	['eric-wieser', 'github-actions', 'grunweg', 'leanprover-community-bot-assistant']	nobody	83-5828 2 months ago	105-68150 3 months ago	7-54661 7 days
28042	kckennylau author:kckennylau	feat(Topology/ValuativeRel): a topological basis indexed by pairs of elements	--- The pullback PR of #27314 and #27163. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-ring-theory merge-conflict	140/23	Mathlib/RingTheory/Valuation/ValuativeRel.lean,Mathlib/Topology/Algebra/Valued/ValuativeRel.lean	2	3	['github-actions', 'grunweg', 'mathlib4-merge-conflict-bot']	nobody	83-5782 2 months ago	83-5782 2 months ago	7-4998 7 days
27399	MoritzBeroRoos author:MoritzBeroRoos	chore: replace every usage of ⬝ᵥ (with old \cdot) by ·ᵥ (with \centerdot)	Discussion at [zulip](https://leanprover.zulipchat.com/#narrow/channel/270676-lean4/topic/.5Ccdot.20!.3D.20.5Ccenterdot). Currently the abbreviations `\cdot` and `\centerdot` resolve to different, with the naked eye nearly undistinguishable symbols (despite the c in cdot surely standing for `center`..): - `\cdot` gives ⬝ [U+2B1D](https://www.compart.com/en/unicode/U+2B1D) "Black Very Small Square" - `\centerdot` gives · [U+00B7](https://www.compart.com/en/unicode/U+00B7) "Middle Dot" Mathlib mostly uses the `\centerdot` variant, except for the dotProduct notation and some probably unsuspecting people wanting \centerdot but getting \cdot in their comments and 6 uses of a notation using the raw `\cdot` without any subscript at `Mathlib\Topology\Homotopy\Product.lean`. This PR replaces the dot product `⬝ᵥ` with its `\centerdot` counterpart `·ᵥ`. The related PR [here](https://github.com/leanprover/vscode-lean4/pull/639) can then overwrite the `\cdot` abbreviation, to produce the same symbol as the `centerdot` abbreviation does. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor merge-conflict	133/133	Mathlib/Analysis/CStarAlgebra/CStarMatrix.lean,Mathlib/Analysis/InnerProductSpace/PiL2.lean,Mathlib/Combinatorics/Configuration.lean,Mathlib/Combinatorics/SimpleGraph/AdjMatrix.lean,Mathlib/Combinatorics/SimpleGraph/LapMatrix.lean,Mathlib/Data/Matrix/Block.lean,Mathlib/Data/Matrix/ConjTranspose.lean,Mathlib/Data/Matrix/Hadamard.lean,Mathlib/Data/Matrix/Mul.lean,Mathlib/Data/Matrix/Notation.lean,Mathlib/Data/Matrix/Reflection.lean,Mathlib/Data/Matrix/RowCol.lean,Mathlib/Data/Matrix/Vec.lean,Mathlib/LinearAlgebra/CrossProduct.lean,Mathlib/LinearAlgebra/Matrix/BilinearForm.lean,Mathlib/LinearAlgebra/Matrix/DotProduct.lean,Mathlib/LinearAlgebra/Matrix/Nondegenerate.lean,Mathlib/LinearAlgebra/Matrix/Orthogonal.lean,Mathlib/LinearAlgebra/Matrix/PosDef.lean,Mathlib/LinearAlgebra/Matrix/SchurComplement.lean,Mathlib/LinearAlgebra/Matrix/SesquilinearForm.lean,Mathlib/LinearAlgebra/Matrix/Trace.lean,Mathlib/LinearAlgebra/PerfectPairing/Matrix.lean,Mathlib/LinearAlgebra/Projectivization/Constructions.lean,Mathlib/Topology/Instances/Matrix.lean	25	6	['MoritzBeroRoos', 'eric-wieser', 'github-actions', 'leanprover-community-bot-assistant']	nobody	82-54060 2 months ago	105-68151 3 months ago	7-62439 7 days
25889	plp127 author:plp127	fix(Tactic/Widget/Conv): fix various issues	Fixes various issues with the `conv?` widget. Closes #25162. ([Zulip thread](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/bug.20in.20.60conv.3F.60)) Specifically, fixes issues with `conv?` where - when converting a `SubExpr.Pos` to conv directions, it always uses the goal expression as reference, even when working on a hypothesis, this often leads to bad results and makes it unusable on hypotheses - it refuses to go all the way in to a function (for example in `Nat.succ 0`, you can't access `Nat.succ`) - it refuses to enter binders where the name of the bound variable contains the character `0` (try it on `∀ (x0 : Nat), x0 = x0`) - it panics if it can't find a binder name instead of just coming up with one itself, this also means usually you can't enter either side of a non-dependent arrow since those usually don't have binder names (try it on `False → False`) - you can't enter the type of a binder, you end up going into the body instead (try it on `fun (x : False) => (x.elim : False → Nat) x.elim`) - you can't partially enter a function, you end up going to the top argument after instead (for example, in the expression `id (id id) 0`, when you click on `id (id id)`, you end up going to `id id`) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-meta merge-conflict	419/84	Mathlib/Tactic/Widget/Conv.lean,MathlibTest/conv?.lean	2	5	['bryangingechen', 'github-actions', 'mathlib4-merge-conflict-bot', 'plp127']	bryangingechen and kmill assignee:kmill assignee:bryangingechen	81-42353 2 months ago	81-42354 2 months ago	70-58775 70 days
28708	sjh227 author:sjh227	feat (Data) : edit DoublyStochastic, add Stochastic to matrix	edit DoublyStochastic add Stochastic --- Add the file Stochastic to matrix. Edit DoublyStochastic so that it depends on Stochastic along with a new lemma	t-data new-contributor merge-conflict	249/1	Mathlib.lean,Mathlib/Data/Matrix/DoublyStochastic.lean,Mathlib/Data/Matrix/Stochastic.lean	3	26	['github-actions', 'j-loreaux', 'mathlib4-merge-conflict-bot', 'sjh227']	nobody	78-44772 2 months ago	78-44772 2 months ago	0-78027 21 hours
27785	staroperator author:staroperator	chore(Algebra/Group/Submonoid): golf `Nat.addSubmonoidClosure_one` using `simp`	This should improve the proof readability. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import t-algebra merge-conflict label:t-algebra$	8/15	Mathlib/Algebra/Group/Submonoid/Membership.lean,Mathlib/Algebra/Group/Submonoid/Operations.lean,Mathlib/Algebra/Order/Star/Basic.lean	3	9	['github-actions', 'joneugster', 'leanprover-bot', 'mathlib4-merge-conflict-bot', 'staroperator']	joneugster assignee:joneugster	78-11123 2 months ago	78-11124 2 months ago	26-34065 26 days
28148	kckennylau author:kckennylau	feat(Matrix): Simproc and Rw-proc for Matrix Transpose	Co-authored by Aaron Liu. ```lean example : !![1, 2, 3; 4, 5, 6]ᵀ = !![1, 4; 2, 5; 3, 6] := by rw [transpose_of% 2 3] example : !![1, 2, 3; 4, 5, 6]ᵀ = !![1, 4; 2, 5; 3, 6] := by rw [transpose_of] example : !![1, 2, 3; 4, 5, 6]ᵀ = !![1, 4; 2, 5; 3, 6] := by simp only [matrix_transpose] ``` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-meta merge-conflict	267/8	Mathlib.lean,Mathlib/Data/Matrix/Notation.lean,Mathlib/LinearAlgebra/UnitaryGroup.lean,Mathlib/Tactic.lean,Mathlib/Tactic/Simproc/Matrix.lean,MathlibTest/Simproc/Matrix.lean,MathlibTest/matrix.lean,scripts/noshake.json	8	32	['eric-wieser', 'github-actions', 'kckennylau', 'mathlib4-merge-conflict-bot', 'plp127']	eric-wieser assignee:eric-wieser	78-10994 2 months ago	78-10995 2 months ago	16-54453 16 days
27566	wwylele author:wwylele	feat(Data/Real): Archimedean.embedReal is a ring hom when M is an ordered ring	Also shows that this ends up the same as `LinearOrderedField.inducedOrderRingHom` for fields --- This is a spin-off from #27268 ~~because I got bored~~ . This is not in a high priority as I don't need it for anything yet, but the last lemma shows that `embedReal` is a generalization of `LinearOrderedField.inducedOrderRingHom` (which is only stated for field, and I didn't find when I was making the group embedding). Perhaps we should refactor `Mathlib/Algebra/Order/CompleteField.lean` with the definition here. Indeed, if we replace every `ℝ` with `(R : Type*)[ConditionallyCompleteLinearOrderedField R]` in `Data/Real/Embedding.lean`, the proof still works. What do you think? [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import t-data merge-conflict	220/3	Mathlib/Data/Real/Embedding.lean	1	2	['github-actions', 'mathlib4-merge-conflict-bot']	nobody	69-4113 2 months ago	69-4114 2 months ago	40-32085 40 days
26908	robin-carlier author:robin-carlier	feat(CategoryTheory/Monoidal/DayConvolution): alternative ext principle for unitors	Currently, our infrastructure for left/right unitors for Day convolution of functors `C ⥤ V` do not have satisfactory extensionality principle: the current way to characterize morphisms out of `U ⊛ F` is the default extensionality principle for Day convolution, which characterizes first such functors via functors out of `U ⊠ F`. Left unitors are then obtained using the fact `U ⊠ F` is a left Kan extension of a functor from `PUnit × C` (which is equivalent to `C`) but we did not record on its own this principle. Using the transitivity of left Kan extensions proved in #26899, we directly exhibit `U ⊛ F` as a left Kan extension of `F ⋙ tensorLeft (𝟙_ V)` along `tensorLeft (𝟙_ C)`. The unit of this Kan extension is composed exactly of the morphisms that appear in the [characterization of left unitors](https://leanprover-community.github.io/mathlib4_docs/Mathlib/CategoryTheory/Monoidal/DayConvolution.html#CategoryTheory.MonoidalCategory.DayConvolutionUnit.leftUnitor_hom_unit_app). We also slightly generalize the instances that express that external products with unitors are left Kan extensions, so that they can be used when taking external products with more complicated functors than currently. This is again useful when chaining extensionality lemmas for morphisms out of terms of the form `(F ⊛ U) ⊛ G`. We prove a similar thing for right unitors With this, it should be possible to have a much more satisfactory way of working with Day convolutions: this allows to "elimiinate" units without ending up with terms in an external product. --- - [ ] depends on: #26899 - [ ] depends on: #26906 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-category-theory merge-conflict	307/18	Mathlib/CategoryTheory/Functor/KanExtension/Basic.lean,Mathlib/CategoryTheory/Monoidal/DayConvolution.lean	2	4	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	66-57340 2 months ago	66-57341 2 months ago	0-1812 30 minutes
27150	robin-carlier author:robin-carlier	feat(CategoryTheory/Monoidal/DayConvolution): constructors for braided and symmetric structure on day convolutions monoidal categories	Following the pattern in #27119, we give API to construct `BraidedCategory` and `SymmetricCategory` structures on a monoidal category equipped with a `LawfulDayConvolutionMonoidalCategoryStruct`. To achieve this, we introduce an other type class `LawfulDayConvolutionBraidedCategoryStruct` that bundles an associator isomorphism that behaves like the one constructed for functors in #27067. We provide a noncomputable constructor for this typeclass that takes as input fullness of the "realization" functor to a category of functors, and we show that the typeclasses are sufficient to define the desired structures. --- - [x] depends on: #27067 - [x] depends on: #26820 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-category-theory merge-conflict	826/9	Mathlib/CategoryTheory/Monoidal/DayConvolution.lean,Mathlib/CategoryTheory/Monoidal/DayConvolution/Braided.lean	2	5	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	66-52379 2 months ago	66-53167 2 months ago	0-1002 16 minutes
27119	robin-carlier author:robin-carlier	feat(CategoryTheory/Monoidal/DayConvolution): constructors for closed monoidal day convolution monoidal structures	Following the pattern introduced in #26798 and #26820 and using results of #26879, we introduce a typeclass `LawfulDayConvolutionClosedMonoidalCategoryStruct` that encodes the data needed on a `LawfulDayConvolutionMonoidalCategoryStruct` to define well-behaved internal homs. We give a constructor assuming existence of relevant ends, and prove that this data defines a `MonoidalClosed` instance on the monoidal category structures one can deduce from `LawfulDayConvolutionMonoidalCategoryStruct`. --- - [x] depends on: #27079 - [x] depends on: #27091 - [x] depends on: #26879 - [x] depends on: #26820 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-category-theory merge-conflict	900/9	Mathlib/CategoryTheory/Monoidal/DayConvolution.lean,Mathlib/CategoryTheory/Monoidal/DayConvolution/Closed.lean	2	6	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	65-66230 2 months ago	66-53164 2 months ago	0-1 1 second
28623	gilesgshaw author:gilesgshaw	feat(Logic/Basic): minor additions and simplification of proofs	Add new theorems and simplify proofs. Specifically, we add the family of related theorems `apply_dite_iff_exists`, `apply_dite_iff_forall`, `apply_ite_iff_and` and `apply_ite_iff_or`. For each other 'family' of theorems in the file that is analogous to the above, we do the following - Simplify proofs where possible, e.g. by appealing to the new theorems - Complete the family, if any of the corresponding four are missing - Rename to ensure consistency with the above pattern ---	new-contributor t-logic merge-conflict	83/55	Archive/Examples/IfNormalization/Result.lean,Archive/Examples/IfNormalization/WithoutAesop.lean,Mathlib/Algebra/ContinuedFractions/Computation/Translations.lean,Mathlib/Algebra/MvPolynomial/Variables.lean,Mathlib/Algebra/Notation/Indicator.lean,Mathlib/LinearAlgebra/Matrix/Rank.lean,Mathlib/Logic/Basic.lean,Mathlib/MeasureTheory/Measure/WithDensity.lean,Mathlib/SetTheory/Ordinal/Notation.lean	9	12	['eric-wieser', 'gilesgshaw', 'github-actions', 'mathlib4-merge-conflict-bot', 'plp127']	awainverse assignee:awainverse	65-60091 2 months ago	65-60092 2 months ago	21-3001 21 days
27933	grunweg author:grunweg	chore(OrdNode): format code example in code blocks	Wrap them in code blocks (and unindent them; that indentation is not needed any more). This also avoids warnings from the linter in #27898. ------- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data merge-conflict	459/212	Mathlib/Data/Ordmap/Ordnode.lean	1	4	['eric-wieser', 'github-actions', 'grunweg', 'mathlib4-merge-conflict-bot']	nobody	62-10724 2 months ago	62-10725 2 months ago	39-69478 39 days
26154	ADedecker author:ADedecker	refactor: add refactored APIs for algebraic filter bases	This PR continues the work from #18437. Original PR: https://github.com/leanprover-community/mathlib4/pull/18437	t-topology merge-conflict	651/0	Mathlib.lean,Mathlib/Topology/Algebra/FilterBasis.lean,Mathlib/Topology/Algebra/FilterBasisNew.lean,Mathlib/Topology/Algebra/Nonarchimedean/Bases.lean,Mathlib/Topology/Algebra/Nonarchimedean/BasesNew.lean	5	3	['ADedecker', 'github-actions', 'mathlib4-merge-conflict-bot']	PatrickMassot assignee:PatrickMassot	59-72335 1 month ago	59-72336 1 month ago	87-79752 87 days
26890	robin-carlier author:robin-carlier	feat(CategoryTheory/Monoidal/DayConvolution) : more API for `DayFunctor`	We provide some lemmas that helps characterizing the monoidal structure on `DayFunctor`, they are special cases of the lemmas for `LawfulDayConvolutionMonoidalCategoryStruct`. --- - [ ] depends on: #26824 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-category-theory merge-conflict	1372/19	Mathlib.lean,Mathlib/CategoryTheory/Functor/KanExtension/Basic.lean,Mathlib/CategoryTheory/Monoidal/DayConvolution.lean,Mathlib/CategoryTheory/Monoidal/DayConvolution/DayFunctor.lean	4	n/a	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	57-36127 1 month ago	unknown	unknown
29281	plp127 author:plp127	docs: `Fin.natAdd_castLEEmb`	Change the docstring of `Fin.natAdd_castLEEmb` which confused me when I read it so I rewrote it. PS. this doesn't really follow the naming convention since data should be in `camelCase` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data merge-conflict	2/3	Mathlib/Data/Fin/Embedding.lean	1	2	['github-actions', 'mathlib4-merge-conflict-bot']	nobody	53-64628 1 month ago	53-64629 1 month ago	18-38918 18 days
29330	plp127 author:plp127	chore: define `Fin.cycleIcc` with conditions	Redefine `Fin.cycleIcc` using conditionals instead of composing existing `Fin` operations together. Its worst-case runtime drops from O(n) to O(1). As a bonus, the definition no longer needs explaining. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-group-theory merge-conflict	61/68	Mathlib/GroupTheory/Perm/Fin.lean	1	10	['JovanGerb', 'eric-wieser', 'github-actions', 'mathlib4-merge-conflict-bot', 'plp127', 'tb65536']	nobody	50-83932 1 month ago	50-83933 1 month ago	20-39203 20 days
21950	erdOne author:erdOne	feat(NumberTheory/Padics): the completion of `ℚ` at a finite place is `ℚ_[p]`	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-number-theory merge-conflict	253/1	Mathlib.lean,Mathlib/Algebra/GroupWithZero/WithZero.lean,Mathlib/NumberTheory/Padics/HeightOneSpectrum.lean,Mathlib/NumberTheory/Padics/PadicNumbers.lean,Mathlib/Topology/Algebra/Valued/WithVal.lean,Mathlib/Topology/Algebra/WithZeroMulInt.lean,Mathlib/Topology/Algebra/WithZeroTopology.lean	7	33	['Ruben-VandeVelde', 'erdOne', 'faenuccio', 'github-actions', 'leanprover-community-bot-assistant', 'pechersky', 'smmercuri', 'xroblot']	nobody	48-59042 1 month ago	129-58979 4 months ago	79-1228 79 days
27214	robin-carlier author:robin-carlier	feat(CategoryTheory/Limits/Shapes/Pullback/Categorical): Categorical pullback squares	In this PR, we give the definition and first basic properties of categorical pullback squares. Using our previous work on `CategoricalPullback`, we define a typeclass `CatPullbackSquare T L R B` that asserts that a given `CatCommSq T L R B` is a "pullback square": this is the data of a chosen adjoint equivalence to the canonical functor from the top left corner of the square to the categorical pulback of its leg. Using this equivalence, be derive a universal property for functors from `X`with values in the top left corner of the square: they are equivalent to `CatCommSqOver R B X`, the category of categorical commutative squares over the cospan `R, B` with top left corner `X`. We prove some coherence result for this equivalence, most notably an isomorphism that, given `S : CatCommSqOver R B X`, bundles the two commutative triangles formed by the induced functor, and the coherence between the squares that these isomorphisms satisfy: this is conveniently bundled in the data of a single isomorphisms of `CatCommSqOver R B X`. Finally, we provide a `Prop`-class `IsCatPullbackSquare` that merely asserts the existence (via `Nonempty`) of the relevant data: we show that it is tautotogically equivalent to the propopsition that the canonical functor to the categorical pullback is an equivalence. --- - [ ] depends on: #26679 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-category-theory merge-conflict	786/1	Mathlib.lean,Mathlib/CategoryTheory/Limits/Shapes/Pullback/Categorical/Basic.lean,Mathlib/CategoryTheory/Limits/Shapes/Pullback/Categorical/Square.lean	3	3	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	45-49124 1 month ago	45-49125 1 month ago	0-5521 1 hour
26466	robin-carlier author:robin-carlier	feat(AlgebraicTopology/SimplexCategory/Augmented): the canonical monoid object in the augmented simplex category	Show that in the augmented simplex category, `⦋0⦌` is an internal monoid object. Future work will show that this is in fact the universal monoid object: for any monoidal category `C`, evaluation at `⦋0⦌` induces an equivalence of categories between `Mon_ C` and the category of monoidal functors from `AugmentedSimplexCategory` to `C`. The resulting augmented cosimplicial object one gets from this construction is sometimes called the "monoidal bar construction" attached to a monoid. This PR was split from #25743. --- - [ ] depends on: #25743 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebraic-topology t-category-theory merge-conflict	571/111	Mathlib.lean,Mathlib/AlgebraicTopology/SimplexCategory/Augmented.lean,Mathlib/AlgebraicTopology/SimplexCategory/Augmented/Basic.lean,Mathlib/AlgebraicTopology/SimplexCategory/Augmented/Mon_.lean,Mathlib/AlgebraicTopology/SimplexCategory/Augmented/Monoidal.lean,Mathlib/AlgebraicTopology/SimplexCategory/Basic.lean	6	4	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	44-68526 1 month ago	44-68528 1 month ago	0-1708 28 minutes
26578	robin-carlier author:robin-carlier	feat(CategoryTheory/Limits/Pullbacks/Categorical/CatCospanTransform): adjunctions of categorical cospans	We build upon the bicategory-like structure developed in #26447 and #26412 to define the notion of adjunctions of categorical cospans. This is a structure encoding the data of two `CatCospanTransform`s, along with the usual unit and counit morphisms as part of the data, satisfying the usual left and right triangle identities. We provide basic API for these, such as extracting adjunctions between individual components. We also provide a proof that the notion satisfies a "coherence": with our chosen constructor, the forward direction of the structure `CatCommSq` on the left adjoints correspond to the inverse of the square for the right adjoints through `mateEquiv`. These adjunctions will be used as a substrate for defining equivalences of categorical cospans in a future PR: such an equivalence will be a structure extending a `CatCospanAdjunction` with isomorphisms data on the unit and co-unit (we will however provide alternative constructors in sync with the constructor for equivalences of categories). --- - [x] depends on: #26447 - [x] depends on: #26547 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import t-category-theory merge-conflict	205/0	Mathlib/CategoryTheory/Limits/Shapes/Pullback/Categorical/CatCospanTransform.lean	1	5	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	43-71751 1 month ago	43-74723 1 month ago	0-625 10 minutes
25042	alreadydone author:alreadydone	feat(Topology): restriction/extension of Trivialization and composition with Homeomorph	--- - [x] depends on: #25041 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology merge-conflict	148/2	Mathlib/Topology/FiberBundle/Trivialization.lean,Mathlib/Topology/Maps/Basic.lean	2	4	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	ADedecker assignee:ADedecker	42-74195 1 month ago	42-74196 1 month ago	134-68375 134 days
23621	astrainfinita author:astrainfinita	chore: deprecate `LinearOrderedComm{Monoid, Group}WithZero`	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) - [x] depends on: #20676	t-order t-algebra merge-conflict label:t-algebra$	261/205	Archive/Imo/Imo1998Q2.lean,Counterexamples/LinearOrderWithPosMulPosEqZero.lean,Mathlib/Algebra/Order/Field/Canonical.lean,Mathlib/Algebra/Order/Field/Rat.lean,Mathlib/Algebra/Order/Floor/Ring.lean,Mathlib/Algebra/Order/GroupWithZero/Canonical.lean,Mathlib/Algebra/Order/GroupWithZero/Finset.lean,Mathlib/Algebra/Order/Hom/Monoid.lean,Mathlib/Algebra/Order/Nonneg/Field.lean,Mathlib/Algebra/Order/Nonneg/Ring.lean,Mathlib/Algebra/Order/Ring/Nat.lean,Mathlib/Combinatorics/Additive/PluenneckeRuzsa.lean,Mathlib/Combinatorics/SimpleGraph/Triangle/Basic.lean,Mathlib/Data/ENNReal/Basic.lean,Mathlib/Data/NNRat/Lemmas.lean,Mathlib/Data/NNReal/Defs.lean,Mathlib/Data/Rat/Cast/Order.lean,Mathlib/FieldTheory/IntermediateField/Adjoin/Defs.lean,Mathlib/FieldTheory/RatFunc/AsPolynomial.lean,Mathlib/GroupTheory/ArchimedeanDensely.lean,Mathlib/NumberTheory/EllipticDivisibilitySequence.lean,Mathlib/NumberTheory/FunctionField.lean,Mathlib/NumberTheory/Ostrowski.lean,Mathlib/RingTheory/Valuation/Archimedean.lean,Mathlib/RingTheory/Valuation/Basic.lean,Mathlib/RingTheory/Valuation/ExtendToLocalization.lean,Mathlib/RingTheory/Valuation/Integers.lean,Mathlib/RingTheory/Valuation/Integral.lean,Mathlib/RingTheory/Valuation/Minpoly.lean,Mathlib/RingTheory/Valuation/Quotient.lean,Mathlib/RingTheory/Valuation/RankOne.lean,Mathlib/RingTheory/Valuation/ValExtension.lean,Mathlib/RingTheory/Valuation/ValuationRing.lean,Mathlib/RingTheory/Valuation/ValuationSubring.lean,Mathlib/SetTheory/Cardinal/Order.lean,Mathlib/Topology/Algebra/Valued/LocallyCompact.lean,Mathlib/Topology/Algebra/Valued/NormedValued.lean,Mathlib/Topology/Algebra/Valued/ValuationTopology.lean,Mathlib/Topology/Algebra/Valued/ValuedField.lean,Mathlib/Topology/Algebra/Valued/WithVal.lean,Mathlib/Topology/Algebra/WithZeroTopology.lean,Mathlib/Topology/UnitInterval.lean,MathlibTest/instance_diamonds.lean,scripts/noshake.json	44	n/a	['YaelDillies', 'astrainfinita', 'github-actions', 'grunweg', 'leanprover-bot', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	kbuzzard assignee:kbuzzard	40-53466 1 month ago	unknown	unknown
29587	uniwuni author:uniwuni	feat(GroupTheory/Finiteness): define finitely generated semigroups	We define finitely generated semigroups and basics similarly to monoids and groups and prove that semigroups and monoids remain finitely generated when a congruence is quotiented out. This will be important when further developing semigroup theory. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict	259/14	Mathlib/Algebra/Group/Submonoid/Defs.lean,Mathlib/GroupTheory/Finiteness.lean	2	4	['github-actions', 'mathlib4-merge-conflict-bot', 'plp127', 'uniwuni']	dupuisf assignee:dupuisf	36-75395 1 month ago	36-75396 1 month ago	25-78230 25 days
27990	kckennylau author:kckennylau	feat(Counterexamples): a nontrivial valuation with discrete topology	This file constructs a valuation on `K[X]` satisfying `IsValuativeTopology K[X] ∧ Nonempty (valuation K[X]).RankOne ∧ IsNontrivial K[X] ∧ DiscreteTopology K[X]`, and proves that `IsValuativeTopology F ∧ IsNontrivial F ∧ DiscreteTopology F` is not possible if `F` is a field. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-ring-theory merge-conflict	172/0	Counterexamples.lean,Counterexamples/DiscreteTopologyWithNontrivialValuation.lean	2	n/a	['github-actions', 'grunweg', 'kckennylau', 'mathlib4-merge-conflict-bot', 'pechersky']	nobody	32-55597 1 month ago	unknown	unknown
29378	mans0954 author:mans0954	feat(Analysis/LocallyConvex/AbsConvex): Balanced and AbsConvex sets under linear maps	Provide `Balanced` and `AbsConvex` versions of `Convex.linear_image`, `Convex.linear_preimage` and the `is_linear` equivalents. --- - [ ] depends on: #29342 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-analysis merge-conflict	133/68	Mathlib/Analysis/Convex/Basic.lean,Mathlib/Analysis/LocallyConvex/AbsConvex.lean,Mathlib/Analysis/LocallyConvex/AbsConvexOpen.lean,Mathlib/Analysis/LocallyConvex/BalancedCoreHull.lean,Mathlib/Analysis/LocallyConvex/Basic.lean,Mathlib/Analysis/Normed/Module/Dual.lean	6	4	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	30-12033 30 days ago	30-12034 30 days ago	0-14664 4 hours
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 merge-conflict	0/102	Mathlib/Data/Nat/Digits/Defs.lean	1	2	['github-actions', 'mathlib4-merge-conflict-bot']	nobody	27-44756 27 days ago	27-44756 27 days ago	12-698 12 days
25978	Bergschaf author:Bergschaf	feat(Order/Sublocale): Open Sublocales	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) - [x] depends on: #25089	t-order merge-conflict	377/8	Mathlib.lean,Mathlib/Order/Hom/Lattice.lean,Mathlib/Order/Nucleus.lean,Mathlib/Order/Sublocale.lean,Mathlib/Order/Synonym.lean,docs/references.bib	6	3	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	21-44453 21 days ago	94-2329 3 months ago	0-1908 31 minutes
30690	grunweg author:grunweg	style(Order): fix whitespace	Extracted from #30658. Found by extending the commandStart linter to proof bodies. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-order merge-conflict	69/69	Mathlib/Order/Basic.lean,Mathlib/Order/Bounds/Image.lean,Mathlib/Order/Defs/PartialOrder.lean,Mathlib/Order/Filter/Cocardinal.lean,Mathlib/Order/Heyting/Basic.lean,Mathlib/Order/KonigLemma.lean,Mathlib/Order/Max.lean,Mathlib/Order/Minimal.lean,Mathlib/Order/Monotone/Basic.lean,Mathlib/Order/PiLex.lean,Mathlib/Order/RelClasses.lean,Mathlib/Order/SetIsMax.lean,Mathlib/Order/SetNotation.lean,Mathlib/Order/WithBot.lean	14	4	['JovanGerb', 'github-actions', 'grunweg', 'mathlib4-merge-conflict-bot']	Vierkantor assignee:Vierkantor	16-69632 16 days ago	16-69633 16 days ago	8-67789 8 days
29909	Vierkantor author:Vierkantor	feat(CI): add build output to CI workflows	This PR uses the Zulip build report script (originally developed for the nightly-regression-report workflow) to add a summary of build output to other Zulip posts about workflow results. This allows us to more easily see the origin of a failure. This requires redoing the script a little to make it a bit more flexible, and the output is slightly reformatted to become consistent across the various workflows (4 of them that post to Zulip). We don't do so for the nightly-testing failures, since those run in a different workflow, and it would be a lot of work to access the command output from another workflow. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	CI merge-conflict	93/69	.github/workflows/daily.yml,.github/workflows/nightly-docgen.yml,.github/workflows/nightly-regression-report.yml,scripts/zulip_build_report.sh	4	2	['github-actions', 'mathlib4-merge-conflict-bot']	robertylewis assignee:robertylewis	10-10505 10 days ago	10-10505 10 days ago	41-48286 41 days
28132	dupuisf author:dupuisf	feat: preliminary `grind` tags for `IsUnit`	This PR adds preliminary `grind` tags for the `IsUnit` predicate. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	61/17	Mathlib/Algebra/Group/Action/Units.lean,Mathlib/Algebra/Group/Units/Defs.lean,Mathlib/Algebra/GroupWithZero/Units/Basic.lean,Mathlib/Algebra/Ring/Units.lean,Mathlib/Analysis/CStarAlgebra/ContinuousFunctionalCalculus/Order.lean,Mathlib/Analysis/SpecialFunctions/ContinuousFunctionalCalculus/Rpow/Basic.lean	6	3	['github-actions', 'mathlib4-merge-conflict-bot']	kim-em assignee:kim-em	9-32195 9 days ago	9-32196 9 days ago	80-71575 80 days
30484	vihdzp author:vihdzp	refactor: override `≤` and `<` in `Function.Injective.semilatticeSup`, etc.	These constructors now take `LE` and `LT` instance arguments, and proofs that the "induced" relations are equal. This matches the behavior for all other data fields of the same constructors, which avoids diamonds which could otherwise arise. To recover the old behavior, you can instantiate `LE` and `LT` instances through `PartialOrder.lift` (if they don't exist already), and set the `le` and `lt` fields to `Iff.rfl`. --- I seem to have (somehow?) changed a syntactic equality on fractional ideals - given that this golfs various proofs and even removes a porting note, I think this change is desirable. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-order merge-conflict	392/382	Mathlib/Algebra/Lie/Submodule.lean,Mathlib/Algebra/Module/Injective.lean,Mathlib/Algebra/Order/Kleene.lean,Mathlib/Analysis/Convex/Cone/Dual.lean,Mathlib/Analysis/Normed/Group/Seminorm.lean,Mathlib/Analysis/Seminorm.lean,Mathlib/CategoryTheory/Sites/Precoverage.lean,Mathlib/Combinatorics/Digraph/Basic.lean,Mathlib/Combinatorics/SimpleGraph/Basic.lean,Mathlib/Combinatorics/SimpleGraph/Finsubgraph.lean,Mathlib/Combinatorics/SimpleGraph/Subgraph.lean,Mathlib/Combinatorics/Young/YoungDiagram.lean,Mathlib/FieldTheory/Galois/GaloisClosure.lean,Mathlib/MeasureTheory/MeasurableSpace/MeasurablyGenerated.lean,Mathlib/ModelTheory/Definability.lean,Mathlib/NumberTheory/NumberField/FractionalIdeal.lean,Mathlib/Order/BooleanAlgebra/Basic.lean,Mathlib/Order/BooleanSubalgebra.lean,Mathlib/Order/CompleteBooleanAlgebra.lean,Mathlib/Order/CompleteLattice/Basic.lean,Mathlib/Order/CompleteLattice/Lemmas.lean,Mathlib/Order/CompleteSublattice.lean,Mathlib/Order/Concept.lean,Mathlib/Order/Disjoint.lean,Mathlib/Order/Heyting/Basic.lean,Mathlib/Order/Heyting/Regular.lean,Mathlib/Order/Hom/Bounded.lean,Mathlib/Order/Hom/BoundedLattice.lean,Mathlib/Order/Hom/Lattice.lean,Mathlib/Order/Interval/Basic.lean,Mathlib/Order/Lattice.lean,Mathlib/Order/Nucleus.lean,Mathlib/Order/Sublattice.lean,Mathlib/Order/UpperLower/CompleteLattice.lean,Mathlib/RingTheory/DedekindDomain/Different.lean,Mathlib/RingTheory/DedekindDomain/Factorization.lean,Mathlib/RingTheory/DedekindDomain/Ideal/Basic.lean,Mathlib/RingTheory/DividedPowers/SubDPIdeal.lean,Mathlib/RingTheory/Filtration.lean,Mathlib/RingTheory/FractionalIdeal/Basic.lean,Mathlib/RingTheory/FractionalIdeal/Extended.lean,Mathlib/RingTheory/FractionalIdeal/Inverse.lean,Mathlib/RingTheory/FractionalIdeal/Operations.lean,Mathlib/RingTheory/GradedAlgebra/Homogeneous/Ideal.lean,Mathlib/Topology/Algebra/Group/ClosedSubgroup.lean,Mathlib/Topology/Algebra/Group/GroupTopology.lean,Mathlib/Topology/Algebra/Module/ClosedSubmodule.lean,Mathlib/Topology/Algebra/OpenSubgroup.lean,Mathlib/Topology/ContinuousMap/Bounded/Normed.lean,Mathlib/Topology/ContinuousMap/CompactlySupported.lean,Mathlib/Topology/ContinuousMap/Ordered.lean,Mathlib/Topology/DiscreteQuotient.lean,Mathlib/Topology/Sets/Closeds.lean,Mathlib/Topology/Sets/Compacts.lean,Mathlib/Topology/Sets/Opens.lean,Mathlib/Topology/Sets/Order.lean	56	32	['Vierkantor', 'YaelDillies', 'github-actions', 'leanprover-bot', 'mathlib4-merge-conflict-bot', 'plp127', 'vihdzp']	nobody	8-9286 8 days ago	8-9287 8 days ago	5-71110 5 days
29877	Komyyy author:Komyyy	feat: inner product of the gradient	Also, this PR enables the `conj` notation in the file. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-analysis merge-conflict	37/10	Mathlib/Analysis/Calculus/Gradient/Basic.lean	1	2	['github-actions', 'mathlib4-merge-conflict-bot']	hrmacbeth assignee:hrmacbeth	7-60854 7 days ago	7-60856 7 days ago	45-5432 45 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 merge-conflict	61/17	Mathlib/Combinatorics/SimpleGraph/Connectivity/WalkDecomp.lean,Mathlib/Combinatorics/SimpleGraph/Walk.lean	2	2	['github-actions', 'mathlib4-merge-conflict-bot']	awainverse assignee:awainverse	7-3770 7 days ago	7-3771 7 days ago	62-42811 62 days
29937	Thmoas-Guan author:Thmoas-Guan	feat(RingTheory): `ringKrullDim` of quotient via supportDim	In this PR, we establish some lemma about `ringKrullDim` of quotient via lemmas of `supportDim`. Co-authored-by: Yongle Hu @mbkybky --- - [ ] depends on: #26219 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-ring-theory merge-conflict	290/15	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/Support.lean	8	4	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	3-52976 3 days ago	3-52977 3 days ago	0-8336 2 hours
30441	linesthatinterlace author:linesthatinterlace	fix(Data/List/Sort): Deprecate and replace `List.Sorted`	Deprecates `Sorted` and defines new special-case predicates to be used for preorders. --- `List.Sorted` is essentially an irrelevant definition, as it is identical to List.Pairwise, and we have some results about Sorted which also always apply to Pairwise or do so under certain conditions (and vice versa). We also commonly use Sorted to talk specifically about `<` and `<=`, which can be somewhat unwieldy. This PR deprecates `Sorted` (so that there should now be no non-deprecated definitions under that namespace), and adds in `SortedLE`, `SortedLT`, `SortedGE` and `SortedGT`, which are defined analogously to `List.Nodup` for Preorders (List.Nodup is a good example of somewhere where using a special case of Pairwise works well). The vision is that API for these can be created together and for many purposes will suffice. `insertionSort` has now been moved to be independent of any of this, though theorems are provided showing that it does link to these predicates in a linear order. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict	781/521	Mathlib/AlgebraicTopology/SimplexCategory/GeneratorsRelations/NormalForms.lean,Mathlib/Analysis/Convex/BetweenList.lean,Mathlib/Combinatorics/Young/YoungDiagram.lean,Mathlib/Data/Fin/Tuple/Sort.lean,Mathlib/Data/Finset/Sort.lean,Mathlib/Data/List/Nodup.lean,Mathlib/Data/List/NodupEquivFin.lean,Mathlib/Data/List/OfFn.lean,Mathlib/Data/List/Pairwise.lean,Mathlib/Data/List/Sort.lean,Mathlib/Data/Multiset/Sort.lean,Mathlib/Data/Nat/BitIndices.lean,Mathlib/Data/Nat/Factors.lean,Mathlib/LinearAlgebra/Matrix/Spectrum.lean,Mathlib/Logic/Equiv/Finset.lean,Mathlib/Logic/Equiv/Multiset.lean,Mathlib/NumberTheory/ADEInequality.lean,Mathlib/NumberTheory/Divisors.lean,Mathlib/Order/JordanHolder.lean,Mathlib/Order/Synonym.lean,Mathlib/SetTheory/Ordinal/Basic.lean,Mathlib/SetTheory/Ordinal/CantorNormalForm.lean,Mathlib/Tactic/Simproc/Factors.lean,Mathlib/Topology/Category/Profinite/Nobeling/Basic.lean,Mathlib/Topology/Category/Profinite/Nobeling/Span.lean	25	56	['github-actions', 'joelriou', 'linesthatinterlace', 'mathlib4-merge-conflict-bot', 'vihdzp']	nobody	2-29558 2 days ago	2-29559 2 days ago	26-41807 26 days
26827	pechersky author:pechersky	feat(Analysis/Normed/ValuativeRel): helper instance for NormedField	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) - [x] depends on: #26713 - [x] depends on: #26826	t-algebra t-analysis t-number-theory merge-conflict label:t-algebra$	211/27	Mathlib.lean,Mathlib/Analysis/Normed/ValuativeRel.lean,Mathlib/Topology/Algebra/Valued/ValuativeRel.lean	3	34	['ADedecker', 'adamtopaz', 'erdOne', 'github-actions', 'kbuzzard', 'kckennylau', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'pechersky']	kbuzzard assignee:kbuzzard	1-60799 1 day ago	1-60799 1 day ago	127-58875 127 days
30281	j-loreaux author:j-loreaux	chore(Analysis/{NormedSpace,Normed/Module}): migrate all remaining files	closes #28698 --- - [ ] depends on: #29447 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	file-removed t-analysis merge-conflict	36/36	Mathlib.lean,Mathlib/Analysis/CStarAlgebra/Unitary/Span.lean,Mathlib/Analysis/Calculus/DifferentialForm/Basic.lean,Mathlib/Analysis/Calculus/FDeriv/CompCLM.lean,Mathlib/Analysis/Calculus/FormalMultilinearSeries.lean,Mathlib/Analysis/Calculus/IteratedDeriv/ConvergenceOnBall.lean,Mathlib/Analysis/Complex/AbsMax.lean,Mathlib/Analysis/Convex/AmpleSet.lean,Mathlib/Analysis/Normed/Module/Alternating/Basic.lean,Mathlib/Analysis/Normed/Module/Alternating/Curry.lean,Mathlib/Analysis/Normed/Module/Alternating/Uncurry/Fin.lean,Mathlib/Analysis/Normed/Module/Connected.lean,Mathlib/Analysis/Normed/Module/ENormedSpace.lean,Mathlib/Analysis/Normed/Module/Extr.lean,Mathlib/Analysis/Normed/Module/FiniteDimension.lean,Mathlib/Analysis/Normed/Module/MStructure.lean,Mathlib/Analysis/Normed/Module/Multilinear/Basic.lean,Mathlib/Analysis/Normed/Module/Multilinear/Curry.lean,Mathlib/Analysis/Normed/Module/MultipliableUniformlyOn.lean,Mathlib/Analysis/Normed/Module/Normalize.lean,Mathlib/Analysis/Normed/Module/PiTensorProduct/InjectiveSeminorm.lean,Mathlib/Analysis/Normed/Module/PiTensorProduct/ProjectiveSeminorm.lean,Mathlib/Analysis/Normed/Module/RieszLemma.lean,Mathlib/Analysis/Normed/Operator/BoundedLinearMaps.lean,Mathlib/Analysis/Normed/Operator/CompleteCodomain.lean,Mathlib/Analysis/SpecialFunctions/Integrability/LogMeromorphic.lean,Mathlib/Analysis/SpecialFunctions/Trigonometric/Cotangent.lean,Mathlib/Geometry/Euclidean/SignedDist.lean,Mathlib/NumberTheory/LSeries/ZMod.lean,Mathlib/NumberTheory/ModularForms/DedekindEta.lean	30	5	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	1-54646 1 day ago	1-54647 1 day ago	3-41416 3 days
29014	ShreckYe author:ShreckYe	feat(Data/List/Scan): some theorems that relate `scanl` with `foldl`	I am not sure which is the best form of `getElem_scanl_eq_foldl_take` here, so I added several alternative forms. Feel free to remove any of them if necessary.	t-data merge-conflict	35/0	Mathlib/Data/List/Scan.lean	1	11	['ShreckYe', 'github-actions', 'mathlib4-merge-conflict-bot', 'themathqueen', 'vlad902']	pechersky assignee:pechersky	1-17030 1 day ago	4-14761 4 days ago	74-62841 74 days
27936	alreadydone author:alreadydone	feat(Algebra): additivize Dvd and Prime	`Prime` can't be directly additivized, so we introduce `Preprime`, which drops the `≠ 0` condition, and additivize it to `AddPrime`. To show that `Preprime` is a reasonable definition, we show its connection to `Irreducible` under `IsPrimal` and `IsRegular` conditions. We also show that an element in a product monoid is preprime iff one component is a unit and the other is preprime, and the same with `Preprime` replaced by `Irreducible`. Also additivize `IsPrimal`, `IsRelPrime` and `DecompositionMonoid`. The motivation is that the primality of `single g 1` in `AddMonoidAlgebra k G` is connected to the primality of `g` in `G`. --- I've checked [all 29 files](https://github.com/search?q=repo%3Aleanprover-community%2Fmathlib4%20%E2%88%A3%20to_additive&type=code) containing the `∣` symbol and the `to_additive` attribute and fixed the wrongly translated (`dvd` to `addDvd`) names. TODO: connect (Add)Dvd to [ExistsMul/AddOfLE](https://leanprover-community.github.io/mathlib4_docs/Mathlib/Algebra/Order/Monoid/Unbundled/ExistsOfLE.html#ExistsMulOfLE) [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	400/191	Mathlib.lean,Mathlib/Algebra/BigOperators/Group/Finset/Basic.lean,Mathlib/Algebra/BigOperators/Group/Finset/Defs.lean,Mathlib/Algebra/BigOperators/Group/Finset/Piecewise.lean,Mathlib/Algebra/BigOperators/Group/List/Lemmas.lean,Mathlib/Algebra/BigOperators/Group/Multiset/Basic.lean,Mathlib/Algebra/Divisibility/Basic.lean,Mathlib/Algebra/Divisibility/Finite.lean,Mathlib/Algebra/Divisibility/Hom.lean,Mathlib/Algebra/Divisibility/Prod.lean,Mathlib/Algebra/Divisibility/Units.lean,Mathlib/Algebra/Group/Action/Pointwise/Finset.lean,Mathlib/Algebra/Group/Prod.lean,Mathlib/Algebra/GroupWithZero/Associated.lean,Mathlib/Algebra/Notation/Defs.lean,Mathlib/Algebra/Prime/Defs.lean,Mathlib/Algebra/Prime/Lemmas.lean,Mathlib/Algebra/Prime/Prod.lean,Mathlib/Data/Nat/Prime/Defs.lean,Mathlib/Dynamics/PeriodicPts/Defs.lean,Mathlib/GroupTheory/Coset/Card.lean,Mathlib/GroupTheory/Exponent.lean,Mathlib/GroupTheory/GroupAction/Blocks.lean,Mathlib/GroupTheory/GroupAction/Period.lean,Mathlib/GroupTheory/Index.lean,Mathlib/GroupTheory/OrderOfElement.lean,Mathlib/GroupTheory/Perm/Cycle/Type.lean,Mathlib/GroupTheory/Schreier.lean,Mathlib/GroupTheory/SpecificGroups/Cyclic.lean,Mathlib/Tactic/ToAdditive/GuessName.lean	30	13	['JovanGerb', 'adomani', 'alreadydone', 'bryangingechen', 'github-actions', 'mathlib4-merge-conflict-bot']	bryangingechen assignee:bryangingechen	1-14753 1 day ago	1-14754 1 day ago	98-49698 98 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 merge-conflict	752/0	Mathlib.lean,Mathlib/Dynamics/SymbolicDynamics/Basic.lean,Mathlib/Tactic/ToAdditive/GuessName.lean	3	120	['Sfgangloff', 'eric-wieser', 'github-actions', 'kckennylau', 'mathlib4-merge-conflict-bot', 'sgouezel']	sgouezel assignee:sgouezel	1-14752 1 day ago	1-14753 1 day ago	70-47424 70 days
26484	peabrainiac author:peabrainiac	feat(Geometry/Diffeology): basics of diffeological spaces	Introduces diffeological spaces, smooth maps between them, the D-topology and the standard diffeology on finite-dimensional normed spaces. --- This PR continues the work from #21969.	t-differential-geometry merge-conflict	471/0	Mathlib.lean,Mathlib/Geometry/Diffeology/Basic.lean,docs/references.bib	3	11	['JovanGerb', 'github-actions', 'grunweg', 'lecopivo', 'mathlib4-merge-conflict-bot', 'peabrainiac']	grunweg assignee:grunweg	0-73333 20 hours ago	0-73334 20 hours ago	138-31722 138 days

Stale new contributor PRs

Number	Author	Title	Description	Labels	+/-	Modified files (first 100)	📝	💬	All users who commented or reviewed	Assignee(s)	Updated	Last status change	total time in review
15224	AnthonyBordg author:AnthonyBordg	feat(CategoryTheory/Sites): covering families and their associated Grothendieck topology	Define covering families on a category and their associated Grothendieck topology by using the API for `Coverage`. Give an explicit characterization of the covering sieves of the said topology. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-category-theory awaiting-author	112/0	Mathlib.lean,Mathlib/CategoryTheory/Sites/CoveringFamilies.lean	2	20	['AnthonyBordg', 'adamtopaz', 'dagurtomas', 'github-actions', 'joelriou']	nobody	465-56480 1 year ago	470-50145 1 year ago	1-48443 1 day
14563	awueth author:awueth	feat: if-then-else of exclusive or statement	--- If `¬(P ∧ Q)` then `ite (P ∨ Q) a 1 = (ite P a 1) * (ite Q a 1)` [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra awaiting-author label:t-algebra$	5/0	Mathlib/Algebra/Group/Basic.lean	1	3	['eric-wieser', 'github-actions', 'kim-em']	nobody	455-73856 1 year ago	455-73856 1 year ago	6-38745 6 days
11090	pangelinos author:pangelinos	feat: define spectral spaces and prove that a quasi-compact open of a spectral space is spectral	Define spectral spaces and prove that a quasi-compact open of a spectral space is spectral. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-topology please-adopt good first issue	69/0	Topology/Spectral/basic.lean	1	15	['YaelDillies', 'adomani', 'j-loreaux', 'jcommelin', 'kim-em', 'pangelinos']	nobody	451-58108 1 year ago	455-71034 1 year ago	16-44803 16 days
15121	Eloitor author:Eloitor	feat: iff theorems for IsSplitEpi and IsSplitMono in opposite category	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-category-theory awaiting-author	40/0	Mathlib/CategoryTheory/EpiMono.lean	1	3	['github-actions', 'joelriou', 'mattrobball']	nobody	438-33600 1 year ago	469-79259 1 year ago	7-3203 7 days
14603	awueth author:awueth	feat: degree is invariant under graph isomorphism	--- Mathlib has the definition `SimpleGraph.Iso.mapNeighborSet` which is an equivalence between neighbor sets induced by an isomorphism. Would it be beneficial to add the same equivalence for `neighborFinset`? [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-combinatorics WIP	24/0	Mathlib/Combinatorics/SimpleGraph/Map/Finite.lean	1	11	['awueth', 'github-actions', 'jcommelin', 'kim-em', 'urkud']	nobody	387-52602 1 year ago	387-52602 1 year ago	31-44440 31 days
18461	hannahfechtner author:hannahfechtner	feat: left and right common multiples mixins	add mixins for left and right common multiples. These carry the data of what factors are used to create the common multiples --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra awaiting-author label:t-algebra$	78/0	Mathlib/Algebra/Group/Defs.lean	1	13	['github-actions', 'hannahfechtner', 'jcommelin', 'kbuzzard', 'kim-em', 'trivial1711']	nobody	297-77137 9 months ago	297-77137 9 months ago	69-35596 69 days
20797	vbeffara author:vbeffara	feat(Topology/Covering): CM version of eq_of_comp_eq	Add equivalents of the lemmas `IsCoveringMap.eq_of_comp_eq` and `IsCoveringMap.const_of_comp_CM` for the case of bundled `ContinuousMap` parameters. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-topology easy awaiting-author	9/1	Mathlib/Topology/Covering.lean	1	4	['github-actions', 'ocfnash', 'vbeffara']	nobody	297-63902 9 months ago	298-64855 9 months ago	2-77310 2 days
13442	dignissimus author:dignissimus	feat: mabel tactic for multiplicative abelian groups	Mabel tactic for multiplicative abelian groups (#10361) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-meta modifies-tactic-syntax awaiting-author help-wanted	439/0	Mathlib.lean,Mathlib/Tactic.lean,Mathlib/Tactic/MAbel.lean,MathlibTest/mabel.lean	4	10	['BoltonBailey', 'dignissimus', 'github-actions', 'joneugster', 'kbuzzard']	joneugster assignee:joneugster	267-29665 8 months ago	272-11261 8 months ago	0-16 16 seconds
21501	sksgurdldi author:sksgurdldi	feat(List): add sum_zipWith_eq_finset_sum	### Description: This PR adds the lemma `List.sum_zipWith_eq_finset_sum` to `Mathlib.Algebra.BigOperators.Group.Finset.Basic`. #### Statement: The sum of the `zipWith` operation on two lists equals the sum of applying the operation to corresponding elements of the two lists, indexed over the minimum of their lengths. #### Formal Statement: ```lean lemma sum_zipWith_eq_finset_sum [Inhabited α] [Inhabited β] [AddCommMonoid γ] {op : α → β → γ} (l : List α) (m : List β) : (List.zipWith op l m).sum = ∑ x ∈ (Finset.range (Nat.min l.length m.length)), op (l[x]!) (m[x]!) ``` #### Remarks: - This lemma provides a useful equivalence between `List.zipWith` and summation over a `Finset.range` indexed by `Nat.min l.length m.length`. - It can be helpful in algebraic manipulations involving list-based summations. #### Dependencies: No additional dependencies. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra awaiting-author label:t-algebra$	43/0	Mathlib/Algebra/BigOperators/Group/Finset/Basic.lean	1	1	['github-actions', 'j-loreaux']	nobody	267-28744 8 months ago	267-28744 8 months ago	13-33168 13 days
22302	CharredLee author:CharredLee	feat: add `CategoryTheory.Topos.Power`	This is a continuation of #21281 with the end goal of defining topoi in Mathlib. It introduces the notion of a power object in a category with a subobject classifier, which is a special case of an internal hom. The definition `HasPowerObjects C` contained in this PR is all that remains before `IsTopos C` can be defined. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-category-theory awaiting-author	312/0	Mathlib.lean,Mathlib/CategoryTheory/Topos/Power.lean	2	2	['github-actions', 'joelriou']	b-mehta assignee:b-mehta	261-29940 8 months ago	261-31067 8 months ago	0-1528 25 minutes
22159	shetzl author:shetzl	feat: add definition of pushdown automata	Add the definition of pushdown automata and their two acceptance conditions: acceptance based on empty stack and acceptance based on final state. Co-authored-by: Tobias Leichtfried --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-computability new-contributor awaiting-author	70/0	Mathlib.lean,Mathlib/Computability/PDA.lean	2	34	['YaelDillies', 'github-actions', 'madvorak', 'shetzl']	nobody	241-77487 7 months ago	241-77487 7 months ago	20-81771 20 days
21903	yhtq author:yhtq	feat: add from/toList between `FreeSemigroup` and `List` with relative theorems	Add from/toList between `FreeSemigroup` and `List` with relative theorems, as well as an incidental definition of lexicographic order on `FreeSemigroup`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import new-contributor t-algebra awaiting-CI label:t-algebra$	169/0	Mathlib/Algebra/Free.lean	1	11	['YaelDillies', 'github-actions']	nobody	220-6413 7 months ago	220-6413 7 months ago	51-9403 51 days
22809	b-reinke author:b-reinke	feat: Category algebras and path algebras	This PR defines the category algebra of a linear category and path algebras of quivers. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra t-category-theory WIP label:t-algebra$	218/0	Mathlib/Algebra/Ring/Assoc.lean,Mathlib/CategoryTheory/Linear/CategoryAlgebra.lean,Mathlib/Combinatorics/Quiver/PathAlgebra.lean,Mathlib/Data/DFinsupp/BigOperators.lean	4	2	['b-reinke', 'github-actions']	nobody	194-83884 6 months ago	194-83884 6 months ago	0-0 0 seconds
15649	TpmKranz author:TpmKranz	feat(Computability): introduce Generalised NFA as bridge to Regular Expression	Lays the groundwork for a proof of equivalence of NFA and RE, w.r.t. described language. Actual connection to NFA comes later, after the groundwork for the opposite direction has been laid. Second chunk of #12648 --- - [x] depends on: #15647 [Data.FinEnum.Option unchanged since then] [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-zulip t-computability new-contributor awaiting-author	298/0	Mathlib.lean,Mathlib/Computability/GNFA.lean,Mathlib/Computability/Language.lean,Mathlib/Computability/RegularExpressions.lean,docs/references.bib	5	6	['github-actions', 'mathlib4-dependent-issues-bot', 'meithecatte', 'trivial1711']	nobody	192-30203 6 months ago	192-30212 6 months ago	23-54870 23 days
20648	anthonyde author:anthonyde	feat: formalize regular expression -> εNFA	The file `Computability/RegularExpressionsToEpsilonNFA.lean` contains a formal definition of Thompson's method for constructing an `εNFA` from a `RegularExpression` and a proof of its correctness. --- - [x] depends on: #20644 - [x] depends on: #20645 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-zulip t-computability new-contributor	490/0	Mathlib.lean,Mathlib/Computability/RegularExpressionsToEpsilonNFA.lean,docs/references.bib	3	5	['github-actions', 'mathlib4-dependent-issues-bot', 'meithecatte', 'qawbecrdtey']	nobody	192-29514 6 months ago	192-30149 6 months ago	75-77754 75 days
22314	shetzl author:shetzl	feat: add leftmost derivations for context-free grammars	Leftmost derivations are often easier to reason about than arbitrary derivations. This PR adds leftmost variants of Rewrites, Produces and Derives to the existing definition of context-free grammars and proves that a string of terminals can be derived iff it can be leftmost derived. Co-authored-by: Tobias Leichtfried --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-computability new-contributor awaiting-author	383/0	Mathlib.lean,Mathlib/Computability/LeftmostDerivation.lean	2	54	['YaelDillies', 'github-actions', 'madvorak', 'shetzl']	YaelDillies assignee:YaelDillies	188-74878 6 months ago	188-74878 6 months ago	72-3718 72 days
24008	meithecatte author:meithecatte	chore(EpsilonNFA): replace manual lemmas with @[simps]	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-computability new-contributor awaiting-author	2/24	Mathlib/Computability/EpsilonNFA.lean	1	2	['YaelDillies', 'github-actions', 'urkud']	nobody	186-75742 6 months ago	186-75742 6 months ago	27-52316 27 days
5919	MithicSpirit author:MithicSpirit	feat: implement orthogonality for AffineSubspace	Define `AffineSubspace.orthogonal` and `AffineSubspace.IsOrtho`, as well as develop an API emulating that of `Submodule.orthogonal` and `Submodule.IsOrtho`, respectively. Additionally, provide some relevant lemmas exclusive to affine subspaces, which are mostly to do with the relationship between orthogonality and `AffineSubspace.Parallel`. Closes #5539 --- Still WIP as I need to add more docstrings as well as notations for the new definitions. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-analysis WIP help-wanted	287/0	Mathlib.lean,Mathlib/Analysis/InnerProductSpace/AffineSubspace.lean	2	6	['MithicSpirit', 'eric-wieser', 'github-actions', 'leanprover-community-bot-assistant']	MithicSpirit assignee:MithicSpirit	180-45888 5 months ago	180-45906 5 months ago	0-0 0 seconds
20238	maemre author:maemre	feat(Computability/DFA): Closure of regular languages under some set operations	This shows that regular languages are closed under complement and intersection by constructing DFAs for them. --- Closure under all other operations will be proved when someone adds the proof for DFA<->regular expression equivalence, so they are not part of this PR. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-zulip t-computability new-contributor awaiting-author	159/0	Mathlib/Computability/DFA.lean,Mathlib/Computability/Language.lean	2	59	['EtienneC30', 'YaelDillies', 'github-actions', 'maemre', 'meithecatte', 'urkud']	EtienneC30 assignee:EtienneC30	162-82374 5 months ago	192-30113 6 months ago	48-67492 48 days
24441	MrSumato author:MrSumato	feat(Data/List): add Lyndon-Schutzenberger theorem on list commutativity	Add Lyndon-Schutzenberger theorem on list commutativity. Included definition for List.repeatSelf that returns list repeated n times. --- This is my first mathlib PR, so any comments are highly appreciated. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data new-contributor awaiting-author	129/1	Mathlib.lean,Mathlib/Data/List/Commutativity.lean,Mathlib/Data/List/Defs.lean,Mathlib/Data/List/Lemmas.lean	4	35	['MrSumato', 'github-actions', 'grunweg', 'plp127']	grunweg assignee:grunweg	160-64151 5 months ago	160-64151 5 months ago	29-59355 29 days
23929	meithecatte author:meithecatte	feat(Computability/NFA): improve bound on pumping lemma	--- - [x] depends on: #25321 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-zulip t-computability new-contributor	101/10	Mathlib/Computability/EpsilonNFA.lean,Mathlib/Computability/NFA.lean	2	41	['YaelDillies', 'github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'meithecatte']	nobody	159-39765 5 months ago	159-39766 5 months ago	34-10595 34 days
22790	mhk119 author:mhk119	feat: Extend `taylor_mean_remainder_lagrange` to `x < x_0`	The `taylor_mean_remainder_lagrange` theorem has the assumption that $x_0 < x$. In many applications, we need $x < x_0$ and one cannot use the current version to obtain this (see [zulip](https://leanprover.zulipchat.com/#narrow/channel/116395-maths/topic/Taylor's.20theorem)). This PR introduces a set of theorems that push negations through Taylor expansions so that one can extend `taylor_mean_remainder_lagrange` to the case when $x < x_0$. These theorems should also be useful elsewhere since they are quite general.	new-contributor t-analysis awaiting-author	111/1	Mathlib/Analysis/Calculus/Deriv/Basic.lean,Mathlib/Analysis/Calculus/IteratedDeriv/Lemmas.lean,Mathlib/Analysis/Calculus/Taylor.lean	3	12	['Paul-Lez', 'github-actions', 'grunweg', 'mhk119']	nobody	156-24270 5 months ago	217-65966 7 months ago	30-77130 30 days
25739	literandltx author:literandltx	feat(NumberTheory/LegendreSymbol): Add sqrt‐of‐residue theorems for p=4k+3 and p=8k+5	Add a new file `QuadraticResidueRoots.lean` under `Mathlib/NumberTheory/LegendreSymbol/` that proves two explicit “square-root of quadratic residue” theorems for primes of the specific form. - `exists_sqrt_of_residue_mod4_eq3` for primes `p = 4k + 3` - `exists_sqrt_of_residue_mod8_eq5`* for primes `p = 8*k + 5` It also introduces the helper lemmas `euler_criterion_traditional` and `legendreSym.at_two_mod8_eq_5`. Import lines in `Mathlib.lean` and `Mathlib/NumberTheory/LegendreSymbol/Basic.lean` have been updated accordingly.	new-contributor t-number-theory awaiting-author	217/0	Mathlib.lean,Mathlib/NumberTheory/LegendreSymbol/Basic.lean,Mathlib/NumberTheory/LegendreSymbol/QuadraticReciprocity.lean,Mathlib/NumberTheory/LegendreSymbol/QuadraticResidueRoots.lean	4	2	['github-actions', 'kckennylau']	literandltx assignee:literandltx	136-77627 4 months ago	137-20313 4 months ago	17-63153 17 days
26013	tsuki8 author:tsuki8	feat(Data/Finset/Card,Data/Set/Finite/Basic)	add `card_bijOn` and `finset_subset_preimage_of_finite_image` Add `card_bijOn`: proves that for a bijection between finsets, their cardinalities are equal Add `finset_subset_preimage_of_finite_image`: constructs a finset subset preserving image cardinality Co-authored-by: Junyu Guo --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data new-contributor awaiting-author	15/0	Mathlib/Data/Finset/Card.lean,Mathlib/Data/Set/Finite/Basic.lean	2	5	['Ruben-VandeVelde', 'github-actions']	nobody	135-66002 4 months ago	135-78294 4 months ago	13-85893 13 days
27069	FrankieNC author:FrankieNC	feat(Analysis/MetricSpace/HausdorffDimension): prove dimH of intervals and segments is 1	Add theorems `dimH_Icc01` and `dimH_segment` showing that the Hausdorff dimension of the unit interval [0,1] and of any non-degenerate real segment is 1. The key idea is that the segment is the image of [0,1] under a bi-Lipschitz map. We explicitly construct this map and prove it is both Lipschitz and antilipschitz, allowing us to transfer the dimension result from the unit interval. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-topology awaiting-author	63/0	Mathlib/Topology/MetricSpace/HausdorffDimension.lean	1	10	['AntoineChambert-Loir', 'FrankieNC', 'github-actions', 'grunweg']	nobody	123-38052 4 months ago	123-50536 4 months ago	0-13398 3 hours
26594	metakunt author:metakunt	feat(Algebra/Polynomial/ZMod): Add Polynomial.equiv_of_nat_of_polynomial_zmod	This adds an explicit bijection between the naturals and $$\mathbb{Z}/n\mathbb{Z}[X]$$ in a canonical way. --- I feel that some API is missing to make the theorem shorter, I have no idea what lemmas to extract though. Also I don't know when to use spaces and when not, so I did it best effort.	new-contributor t-algebra awaiting-author label:t-algebra$	465/0	Mathlib.lean,Mathlib/Algebra/Polynomial/ZMod.lean	2	2	['Ruben-VandeVelde', 'github-actions']	nobody	110-40148 3 months ago	110-40148 3 months ago	25-6199 25 days
27297	hugh-fox author:hugh-fox	feat: add an equality between sums and products of cartesian products	Adds `prod_mul_eq_prod_product` and a version for Finsets `prod_range_mul_eq_prod_product` with to show an equality between `Fin (i * j)` and `Fin a × Fin b`. It is likely `prod_range_mul_eq_prod_product` belongs in a different file, in which case only the first commit should be considered. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra awaiting-author label:t-algebra$	12/0	Mathlib/Algebra/BigOperators/Fin.lean	1	6	['Ruben-VandeVelde', 'github-actions', 'hugh-fox', 'j-loreaux', 'kckennylau']	nobody	106-40672 3 months ago	110-32660 3 months ago	7-6727 7 days
14237	js2357 author:js2357	feat: Define the localization of a fractional ideal at a prime ideal	Define the localization of a fractional ideal at a prime ideal, and prove some basic properties. --- This PR is part 3 out of 4 of a proof of `isDedekindDomain_iff_isDedekindDomainDvr`. Part 4 is available here: #14242 - [x] depends on: #14099 Part 1 - [x] depends on: #14216 Part 2 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra awaiting-author label:t-algebra$	230/0	Mathlib.lean,Mathlib/RingTheory/FractionalIdeal/LocalizedAtPrime.lean,Mathlib/RingTheory/Localization/Basic.lean	3	21	['Vierkantor', 'YaelDillies', 'github-actions', 'js2357', 'kbuzzard', 'leanprover-community-bot-assistant', 'leanprover-community-mathlib4-bot']	Vierkantor assignee:Vierkantor	105-50474 3 months ago	105-50506 3 months ago	26-39463 26 days
27753	YunkaiZhang233 author:YunkaiZhang233	feat(CategoryTheory): implemented proofs for factorisation categories being equivalent to iterated comma categories in two ways	--- Completed one of the tasks in TODOs, shown and implemented the details for (X/C)/f ≌ Factorisation f ≌ f/(C/Y). This is migrated from my previous PR #22390 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-category-theory awaiting-author	70/1	Mathlib/CategoryTheory/Category/Factorisation.lean	1	12	['YunkaiZhang233', 'b-mehta', 'github-actions', 'robin-carlier']	nobody	104-57875 3 months ago	105-53756 3 months ago	0-3448 57 minutes
26483	metakunt author:metakunt	feat (RingTheory/RootsOfUnity/PrimitiveRoots) : Add equiv_primitiveRoots_of_coprimePow	Adds equivalence of r-th primitive roots by a coprime e.	t-ring-theory new-contributor awaiting-author	79/0	Mathlib/RingTheory/RootsOfUnity/PrimitiveRoots.lean	1	13	['Citronhat', 'Ruben-VandeVelde', 'github-actions', 'metakunt']	nobody	100-76576 3 months ago	100-76576 3 months ago	28-81831 28 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	98-21030 3 months ago	105-57079 3 months ago	132-44913 132 days
27850	fyqing author:fyqing	feat: 0-dimensional manifolds are discrete and countable	This is the converse direction of the classification of 0-dimensional manifolds. The other direction was shown in #22105. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-differential-geometry awaiting-author	80/0	Mathlib.lean,Mathlib/Geometry/Manifold/ZeroDim.lean	2	13	['fyqing', 'github-actions', 'grunweg', 'tb65536']	grunweg assignee:grunweg	94-67602 3 months ago	104-28418 3 months ago	0-6418 1 hour
27226	xcloudyunx author:xcloudyunx	feat(Combinatorics/SimpleGraph): Add Subgraph.inclusion_edge_apply_coe and inclusion_edgeSet_apply_coe	This PR continues the work from #25248. Original PR: https://github.com/leanprover-community/mathlib4/pull/25248	new-contributor t-combinatorics awaiting-author	14/0	Mathlib/Combinatorics/SimpleGraph/Subgraph.lean	1	3	['b-mehta', 'github-actions', 'xcloudyunx']	b-mehta assignee:b-mehta	94-8989 3 months ago	94-23069 3 months ago	25-83942 25 days
22925	ggranberry author:ggranberry	feat(Mathlib/PlaceHolder/ToeplitzHausdorff): Toeplitz-Hausdorff	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	will-close-soon new-contributor t-analysis awaiting-author WIP help-wanted	411/0	Mathlib/PlaceHolder/ToeplitzHausdorff.lean,Mathlib/PlaceHolder/ToeplitzHausdorff_v2.lean	2	11	['faenuccio', 'ggranberry', 'github-actions']	faenuccio assignee:faenuccio	92-71513 3 months ago	92-71716 3 months ago	4-24257 4 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	86-21045 2 months ago	97-39514 3 months ago	97-39549 97 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	86-21042 2 months ago	95-52372 3 months ago	95-52410 95 days
27479	iu-isgood author:iu-isgood	feat: Abel's Binomial Theorem	We have formalized Abel's Binomial Theorem as part of an REU project. There are a few remaining sorrys, but we will finish them soon. I will edit this PR message later according to community rules. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data new-contributor awaiting-author	326/0	Mathlib/Data/Nat/Choose/AbelBinomial.lean	1	28	['ElifUskuplu', 'FrankieNC', 'github-actions', 'iu-isgood']	nobody	82-53821 2 months ago	106-31718 3 months ago	0-533 8 minutes
24333	xcloudyunx author:xcloudyunx	feat(Combinatorics/SimpleGraph): cycle graph implementation for generic vertex types	The existing `cycleGraph` implementation under Combinatorics/SimpleGraph/Circulant.lean only operates over `Fin n`. This PR implements a cycle graph implementation over any generic vertex type. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-combinatorics awaiting-author	187/0	Mathlib.lean,Mathlib/Combinatorics/SimpleGraph/Cycle.lean	2	41	['IvanRenison', 'github-actions', 'vlad902']	kmill assignee:kmill	80-81880 2 months ago	80-81880 2 months ago	123-22718 123 days
27155	Pjotr5 author:Pjotr5	feat: Shearer's bound on the independence number of triangle free graphs	I added the file IndependenceNumber.lean to the Mathlib.Combinatorics.SimpleGraph.Triangle folder. It contains a proof of a theorem by Shearer on the independence number of triangle-free graphs . I was told this might be useful to add to Mathlib a Zullip thread linked [here](https://leanprover.zulipchat.com/#narrow/channel/217875-Is-there-code-for-X.3F/topic/Convexity.20of.20a.20specific.20function/with/510469526). I tried to comply as much as I could with the Mathlib style guide, but I realise that there is probably still a significant amount of editing to be done. For one thing: there are probably some lemmas and theorems in there that might be better suited in other files, but since this is my first PR I though I would all put it in one file before starting to edit a bunch of files. I was also advised to split up the file into multiple smaller PRs, but since everything is basically serving this one proof I could not really find a natural way to do that. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-combinatorics awaiting-author	1266/0	Mathlib.lean,Mathlib/Combinatorics/SimpleGraph/Triangle/IndependenceNumber.lean	2	9	['Pjotr5', 'github-actions', 'grunweg']	nobody	79-84848 2 months ago	82-53057 2 months ago	39-17587 39 days
27242	hugh-fox author:hugh-fox	feat: add Gauss-like formula for sums of digit sums	Adds `sum_digit_sum_base_pow_eq` to show a Gauss-like formula across sums of digit sums. This relies on an additional two simp lemmas, named `digits_sum_eq_self`, `digits_sum_base_mul_cancel`. Lastly, includes a specialization (which is a good bit simpler than the general formula) to base 10 named `sum_digit_sum_ten_pow_eq`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import t-data new-contributor awaiting-author	113/0	Mathlib/Data/Nat/Digits/Lemmas.lean	1	5	['github-actions', 'hugh-fox', 'kckennylau']	nobody	79-59817 2 months ago	79-59817 2 months ago	39-41606 39 days
27261	Sebi-Kumar author:Sebi-Kumar	feat(Topology): add definition for subpaths	Define subpaths as restrictions of paths to subintervals, reparameterized to have domain `[0, 1]` and possibly with a reverse of direction. Prove their basic properties. This serves as an alternative to `Path.truncate` which is useful for the explicit construction of certain homotopies, in particular regarding the concatenation of subpaths. --- To provide additional context, this is my first time contributing to Mathlib, and I am doing so as a part of the Fields Undergraduate Summer Research Program hosted at Western University. My intention for this file is for it to be used when proving that the fundamental group of the sphere is trivial (following the proof from Hatcher's "Algebraic Topology"). [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-topology awaiting-author	146/0	Mathlib.lean,Mathlib/Topology/Subpath.lean	2	24	['ADedecker', 'FrankieNC', 'Sebi-Kumar', 'github-actions', 'themathqueen', 'wwylele']	ADedecker assignee:ADedecker	78-61257 2 months ago	84-29748 2 months ago	34-15767 34 days
26156	oliver-butterley author:oliver-butterley	feat(MeasureTheory.VectorMeasure) : add a definition of total variation for VectorMeasure	This PR adds variation for any `VectorMeasure` using a supremum definition. Currently mathlib has `TotalVariation` defined for a signed measure using the Hahn-Jordan decomposition, but this doesn't generalise. Motivation: generally this is an important concept but specifically as a step for proving RMK in the complex case which in turn is a step to prove the spectral theorem. Co-authored-by: @yoh-tanimoto This PR was migrated from #25442. PR divided into smaller pieces, this is just the definition without additional lemmas. PRs adding further results related to variation are: * #26160 * #26165 * #26168 (shows that for `SignedMeasures` the two definitions of variation coincide) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-measure-probability awaiting-author	358/0	Mathlib.lean,Mathlib/MeasureTheory/VectorMeasure/Variation/Defs.lean	2	32	['EtienneC30', 'github-actions', 'yoh-tanimoto']	EtienneC30 assignee:EtienneC30	74-60284 2 months ago	105-53404 3 months ago	42-9361 42 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	69-73495 2 months ago	69-73495 2 months ago	75-59676 75 days
26881	emo916math author:emo916math	feat(Analysis/Calculus/Deriv/Star) A formula for `deriv (conj ∘ f ∘ conj)`	Added a lemma that `deriv (conj ∘ f ∘ conj) = conj ∘ deriv f ∘ conj`, proved by cases on whether the derivative mathematically exists or not. This PR replaces [#26805](https://github.com/leanprover-community/mathlib4/pull/26805); see discussion there. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-analysis awaiting-author	50/2	Mathlib/Analysis/Calculus/Deriv/Star.lean	1	15	['emo916math', 'github-actions', 'j-loreaux', 'kckennylau']	j-loreaux assignee:j-loreaux	66-55120 2 months ago	97-54674 3 months ago	31-70593 31 days
26462	PSchwahn author:PSchwahn	feat(LinearAlgebra/Projection): add results about inverse of `Submodule.prodEquivOfIsCompl`	Add two theorems `Submodule.prodEquivOfIsCompl_symm_apply` and `Submodule.prodEquivOfIsCompl_symm_add`, which are API for `Submodule.prodEquivOfIsCompl`. We believe these theorems are useful; for example, we have used their statements in a [classification formalization project](https://github.com/LieLean/LowDimSolvClassification). Co-authored by: - [Viviana del Barco](https://github.com/vdelbarc) - [Gustavo Infanti](https://github.com/GuQOliveira) - [Exequiel Rivas](https://github.com/erivas) --- I am not sure whether the `prodEquivOfIsCompl_symm_apply` theorem should be tagged with `@[simp]`; this might lead to confluence issues. Opinions are welcome! [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra awaiting-author label:t-algebra$	10/0	Mathlib/LinearAlgebra/Projection.lean	1	7	['PSchwahn', 'github-actions', 'joelriou', 'kckennylau']	joelriou assignee:joelriou	66-25189 2 months ago	66-56292 2 months ago	73-43225 73 days
29434	ntapiam author:ntapiam	feat(NonAssoc/LieAdmissible): prove every ring/algebra is LieAdmissible	-awaiting-author	new-contributor t-algebra label:t-algebra$	27/6	Mathlib/Algebra/NonAssoc/LieAdmissible/Defs.lean	1	1	['github-actions']	nobody	65-82968 2 months ago	66-75744 2 months ago	66-75780 66 days
28286	bwangpj author:bwangpj	feat(Geometry/Manifold/ContMDiff): basic lemmas for analytic (`C^ω`) functions	Add basic lemmas relating `ContMDiff` in the `C^ω` case to being `Analytic` on charts. This is upstreamed from [https://github.com/girving/ray](https://github.com/girving/ray). Co-authored-by: Geoffrey Irving --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-differential-geometry awaiting-author	36/0	Mathlib/Geometry/Manifold/ContMDiff/Defs.lean	1	13	['bwangpj', 'girving', 'github-actions', 'grunweg', 'kbuzzard', 'sgouezel']	sgouezel assignee:sgouezel	65-39944 2 months ago	65-80379 2 months ago	27-76128 27 days
25778	thefundamentaltheor3m author:thefundamentaltheor3m	feat: Monotonicity of `setIntegral` for nonnegative functions	This PR makes it easier to prove monotonicity of the Bochner integral on sets for nonnegative functions by removing the stronger assumption required by the general monotonicity lemma that both of the functions being compared must be integrable. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-measure-probability awaiting-author	8/0	Mathlib/MeasureTheory/Integral/Bochner/Set.lean	1	6	['RemyDegenne', 'github-actions', 'sgouezel', 'thefundamentaltheor3m']	nobody	63-55813 2 months ago	154-63646 5 months ago	0-11893 3 hours
28175	dsfxcimk author:dsfxcimk	feat: exterior angle theorem	Add Exterior angle theorem --- The Exterior Angle Theorem states that the exterior angle of a triangle equals the sum of the two non-adjacent interior angles. I plan to place this in Mathlib.Geometry.Euclidean.Triangle [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-euclidean-geometry awaiting-author	10/0	Mathlib/Geometry/Euclidean/Triangle.lean,docs/1000.yaml	2	16	['FrankieNC', 'JovanGerb', 'dsfxcimk', 'github-actions', 'grunweg', 'mathlib4-merge-conflict-bot', 'themathqueen']	nobody	51-50900 1 month ago	65-63767 2 months ago	28-57160 28 days
29588	Periecle author:Periecle	feat(Analysis/Complex/Residue): Implement residue theory for complex functions at isolated singularities	# Add basic residue theory for complex functions This PR introduces the residue theory implementation in mathlib. ## Main additions - `HasIsolatedSingularityAt f c`: Predicate for functions with isolated singularities at point `c` - `residue f c hf`: The residue of `f` at isolated singularity `c`, defined via circle integrals - Radius independence: `residue_eq_two_pi_I_inv_smul_circleIntegral` - residue equals normalized circle integral for any valid radius - Holomorphic residues: `residue_of_holomorphic` - functions holomorphic in a neighborhood have zero residue - Simple pole formula: `residue_simple_pole` - for `f(z) = (z-c)⁻¹ * g(z)`, residue equals `g(c)` ## Implementation notes - Builds on existing circle integral infrastructure in `CauchyIntegral.lean` - Uses `Classical.choose` to extract witness radius from isolated singularity condition - Comprehensive documentation with mathematical context and examples - Establishes foundation for residue theorem, argument principle, and other applications ## Examples included - `residue(1/z, 0) = 1` (canonical simple pole) - Radius independence demonstration - Zero residues for holomorphic functions This provides the essential building blocks for complex analysis and first step to formalize residue theory.	new-contributor t-analysis awaiting-author	383/0	Mathlib/Analysis/Complex/Residue/Basic.lean	1	17	['Periecle', 'github-actions', 'hrmacbeth', 'llllvvuu', 'loefflerd']	nobody	50-59291 1 month ago	61-61394 2 months ago	1-5255 1 day
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	50-50692 1 month ago	81-40929 2 months ago	81-40961 81 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	42-74948 1 month ago	80-7391 2 months ago	86-63257 86 days
30142	shalliso author:shalliso	feat(Topology/Baire): define IsNonMeagre	non-meagre sets (also known as "of the second category") are worthy of their own definition and API. This was useful to me for formalizing a result of "automatic continuity", that is, a Baire-measurable homomorphism between Polish groups must be continuous. Simply working with the negation of IsMeagre quickly became cumbersome, and non-meagre sets have an important role in the study of Polish (e.g. locally compact) groups. From https://github.com/shalliso/automatic_continuity [ ] depends on: #30141 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-topology	83/1	Mathlib/Topology/Baire/NonMeagre.lean,Mathlib/Topology/GDelta/Basic.lean	2	1	['github-actions']	nobody	42-31422 1 month ago	42-31424 1 month ago	42-31463 42 days
28630	Antidite author:Antidite	feat(Archive/Imo): right isosceles configuration in the complex plane	feat(Archive/Imo): right isosceles configuration in the complex plane This adds `Archive/Imo/Imo1975Q3.lean`, formalizing a triangle configuration with points A=0, B=1, C=z and auxiliary points R, P, Q built via complex rotations and sine-based scale factors. Main results: * `angle_and_distance`: ∠QRP = π/2 and dist Q R = dist R P. * Key identity `QRP_rot90`: (Q z).z − R.z = e^{iπ/2} · ((P z).z − R.z). Design/Style: * Minimal imports; module docstring; semantic lemma names; all definitions and theorems live under the namespace `IMO.TriangleConfig`. Moves: - (none) Deletions: - (none) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	IMO new-contributor awaiting-author	196/0	Archive.lean,Archive/Imo/Imo1975Q3.lean	2	36	['Antidite', 'LLaurance', 'github-actions', 'jsm28']	jsm28 assignee:jsm28	40-40081 1 month ago	40-40081 1 month ago	46-38383 46 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	38-21043 1 month ago	45-81531 1 month ago	45-83108 45 days
29361	FlAmmmmING author:FlAmmmmING	feat: Catalan generating function as a formal power series	We introduce the Catalan generating function as a formal power series over `ℕ`. ## Main Definitions * `PowerSeries.catalanSeries`: The Catalan generating function as a power series. ## Main Results * `PowerSeries.sum_coeff_X_catalanSeries`: When `n` is a natural number, each term in the sum `coeff i X * catalan (n - i)` is 0 except for `i = 1`. * `PowerSeries.coeff_X_mul_catalanSeries`: The coefficient of `X * catalanSeries` at `X^n` is `catalan (n - 1)` when `n > 0`. * `PowerSeries.catalanSeries_one_add_X_mul_self_sq`: The Catalan generating function satisfies the equation `catalanSeries = 1 + X * catalanSeries ^ 2`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-ring-theory new-contributor	71/0	Mathlib.lean,Mathlib/RingTheory/PowerSeries/Catalan.lean	2	4	['Ruben-VandeVelde', 'github-actions', 'wwylele']	kbuzzard assignee:kbuzzard	36-84040 1 month ago	69-80115 2 months ago	69-80143 69 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']	b-mehta assignee:b-mehta	35-21041 1 month ago	57-70041 1 month ago	57-70085 57 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']	awainverse assignee:awainverse	34-21051 1 month ago	50-50974 1 month ago	50-51012 50 days
29798	Cyantain author:Cyantain	feat(FieldTheory/IsIntegrallyClosed): lemma to judge whether an element is integral	In this PR, we proved that an element is integral iff it's root of irreducible polynomial with unit leading coeff, which is an easy way to judge an element is integral or not, such as $\sqrt 5 / 4$, because it's root of $16x^2-5$ with not unit leading coeff, so it's not integral.	new-contributor t-algebra delegated awaiting-author label:t-algebra$	13/0	Mathlib/FieldTheory/Minpoly/IsIntegrallyClosed.lean	1	9	['Ruben-VandeVelde', 'adomani', 'github-actions', 'kckennylau', 'mathlib-bors', 'riccardobrasca']	riccardobrasca assignee:riccardobrasca	31-79783 1 month ago	31-79783 1 month ago	6-29891 6 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 awaiting-author	78/1	Mathlib/Probability/Kernel/IonescuTulcea/Traj.lean	1	11	['EtienneC30', 'RemyDegenne', 'github-actions']	EtienneC30 assignee:EtienneC30	29-49656 29 days ago	30-55841 30 days ago	5-85924 5 days
30460	janithamalith author:janithamalith	feat(Nat): add lemma nat_card_orbit_mul_card_stabilizer_eq_card_group	Added a lemma `nat_card_orbit_mul_card_stabilizer_eq_card_group` which is the Nat.card version of MulAction.card_orbit_mul_card_stabilizer_eq_card_group --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-group-theory new-contributor awaiting-author	6/0	Mathlib/GroupTheory/GroupAction/CardCommute.lean	1	17	['github-actions', 'kckennylau', 'plp127', 'tb65536']	tb65536 assignee:tb65536	24-59636 24 days ago	24-59636 24 days ago	8-8414 8 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']	pechersky assignee:pechersky	24-21030 24 days ago	50-42486 1 month ago	68-38681 68 days
30344	Deep0Thinking author:Deep0Thinking	feat(MeasureTheory/Integral): add versions of `exists_eq_interval_average` and first mean value theorem for integrals	Add the First mean value theorem for (unordered) interval integrals on ℝ. - `exists_eq_const_mul_interval_integral_of_continuous_on_of_ae_nonneg` - `exists_eq_const_mul_interval_integral_of_continuous_on_of_nonneg` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-measure-probability	290/41	Mathlib.lean,Mathlib/MeasureTheory/Integral/IntervalAverage.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral/MeanValue.lean	3	9	['Deep0Thinking', 'github-actions', 'plp127']	RemyDegenne assignee:RemyDegenne	24-16971 24 days ago	36-38396 1 month ago	36-38427 36 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 awaiting-author	401/66	Mathlib.lean,Mathlib/CategoryTheory/Closed/PowerObjects.lean,Mathlib/CategoryTheory/Limits/Shapes/BinaryProducts.lean,Mathlib/CategoryTheory/Limits/Shapes/Equalizers.lean,Mathlib/CategoryTheory/Limits/Shapes/Pullback/CommSq.lean,Mathlib/CategoryTheory/Limits/Shapes/Pullback/Equalizer.lean,Mathlib/CategoryTheory/Monoidal/Cartesian/Basic.lean,Mathlib/CategoryTheory/Subobject/Basic.lean,Mathlib/CategoryTheory/Topos/Classifier.lean	9	16	['fweth', 'github-actions', 'joelriou', 'leanprover-community-bot-assistant', 'mathlib4-merge-conflict-bot']	joelriou assignee:joelriou	23-58009 23 days ago	23-58009 23 days ago	62-83085 62 days
25225	xcloudyunx author:xcloudyunx	feat(Combinatorics/SimpleGraph): Eulerian walk in connected graph contains all vertices	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-combinatorics awaiting-author	16/0	Mathlib/Combinatorics/SimpleGraph/Trails.lean	1	6	['IvanRenison', 'github-actions', 'vlad902']	kmill assignee:kmill	23-23168 23 days ago	23-23168 23 days ago	148-3717 148 days
30746	jeremypparker author:jeremypparker	feat(Data/EReal): toReal_pos	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data new-contributor easy	4/0	Mathlib/Data/EReal/Basic.lean	1	2	['github-actions', 'jeremypparker']	nobody	22-66274 22 days ago	23-74275 23 days ago	23-74315 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 awaiting-author	1310/0	Archive.lean,Archive/Imo/Imo2025Q1.lean	2	8	['github-actions', 'kim-em', 'mathlib4-merge-conflict-bot', 'zhuyizheng']	dwrensha assignee:dwrensha	22-58978 22 days ago	23-23682 23 days ago	65-5080 65 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	202/15	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	85	['JovanGerb', 'LessnessRandomness', 'Timeroot', 'github-actions', 'jsm28', 'mathlib4-merge-conflict-bot', 'themathqueen']	jsm28 assignee:jsm28	21-63769 21 days ago	24-50018 24 days ago	145-32592 145 days
30821	chriseth author:chriseth	fix(Computability/Tape): introduce write-simplification theorem that uses `ListBlank.mk`	Add a simplification theorem which is a version of `Tape.write_mk'` that solves a simplification dead-end: If we have an expression of the form `(Tape.mk' L (ListBlank.cons a (ListBlank.mk R))).write b`, the theorem `Tape.write_mk'` would be applicable, but lean instead uses `ListBlank.cons_mk`, which turns it into `(Tape.mk' L (ListBlank.mk (a :: R))).write b` and makes `Tape.write_mk` no longer applicable because it requires `ListBlank.cons a R`, reaching a dead-end. This PR adds an equivalent theorem whose LHS allows `ListBlank.mk (a :: R)`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-computability new-contributor	7/0	Mathlib/Computability/Tape.lean	1	1	['github-actions']	nobody	21-57799 21 days ago	21-57808 21 days ago	21-57850 21 days
30828	DeVilhena-Paulo author:DeVilhena-Paulo	feat: implementation of `Finmap.merge`	The main contribution of this pull request is the implementation of a `merge` function for finite maps (`Finmap`). The construction relies on the definition of a `merge` function for association lists (`AList`). There is also a side (unrelated) contribution on `Mathlib/Data/List/Permutation.lean`: the addition of a theorem about the permutation of a list with a head element (that is, a list of the form `a :: l`). --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data new-contributor	449/3	Mathlib/Data/Finmap.lean,Mathlib/Data/List/AList.lean,Mathlib/Data/List/Permutation.lean,Mathlib/Data/List/Sigma.lean	4	1	['github-actions']	nobody	21-46600 21 days ago	21-46679 21 days ago	21-46727 21 days
29437	SnirBroshi author:SnirBroshi	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	104/0	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']	pechersky assignee:pechersky	21-21047 21 days ago	57-68250 1 month ago	66-55737 66 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 awaiting-author	26/0	Mathlib/Combinatorics/Enumerative/Partition.lean	1	6	['WangYiran01', 'github-actions', 'kckennylau', 'kim-em']	b-mehta assignee:b-mehta	18-77864 18 days ago	23-24579 23 days ago	102-52887 102 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 awaiting-author	227/0	Mathlib.lean,Mathlib/Geometry/Manifold/PrincipalFiberBundle/PrincipalGBundle.lean	2	5	['github-actions', 'grunweg']	hrmacbeth assignee:hrmacbeth	17-55095 17 days ago	17-55095 17 days ago	25-22983 25 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. --- - [x] depends on: #30806	new-contributor	223/1	Mathlib.lean,Mathlib/LinearAlgebra/TensorProduct/Tower.lean,Mathlib/RingTheory/TensorProduct/IncludeLeftSubRight.lean,Mathlib/RingTheory/TensorProduct/Maps.lean	4	7	['erdOne', 'github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'yonggyuchoimath']	TwoFX assignee:TwoFX	17-9954 17 days ago	17-13225 17 days ago	44-81603 44 days
30667	FrederickPu author:FrederickPu	Subgroup mul	Title: Algebra: pointwise products for subgroups Description: showed the point-wise product of disjoint subgroups is equivalent to their Cartesian product --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra awaiting-author label:t-algebra$	47/0	Mathlib/Algebra/Group/Subgroup/Pointwise.lean	1	10	['FrederickPu', 'eric-wieser', 'github-actions', 'plp127', 'tb65536']	nobody	16-59598 16 days ago	25-49632 25 days ago	0-46291 12 hours
31102	JOSHCLUNE author:JOSHCLUNE	Require LeanHammer	Experimenting with adding LeanHammer as a mathlib dependency --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor	61/4	Mathlib/Tactic/Common.lean,Mathlib/Tactic/Linter/DirectoryDependency.lean,MathlibTest/Hammer.lean,lake-manifest.json,lakefile.lean	5	1	['github-actions']	nobody	14-34490 14 days ago	14-41398 14 days ago	14-41383 14 days
30525	515801431 author:515801431	Polya_counting	This PR introduces basic definitions and results about colorings under permutation group actions. A coloring is defined as a function X → Y, and the permutation group Equiv.Perm X acts on colorings by precomposition: (g • c) x = c (g⁻¹ • x) This formalizes the natural action of relabeling the elements of X. Main definitions MulAction (Equiv.Perm X) (X → Y): The action of the permutation group on colorings via precomposition. coloringEquiv (c₁ c₂ : X → Y) : Prop: Two colorings are equivalent if they lie in the same orbit under this action, i.e. ∃ f : Equiv.Perm X, f • c₁ = c₂. Main results smul_eq_iff_mem_stabilizer: Characterizes when two group actions on the same coloring are equal, showing that g • c = f • c ↔ f⁻¹ * g ∈ stabilizer c. coloringEquiv_equivalence: Proves that coloringEquiv defines an equivalence relation on X → Y. orbit_size_eq_index: Reformulates the orbit–stabilizer theorem in the context of colorings: \|orbit c\| = \|Perm X\| / \|stabilizer c\| Motivation These results provide foundational infrastructure for studying Burnside’s lemma and Pólya’s enumeration theorem in Mathlib, where the enumeration of distinct colorings up to symmetry plays a central role.	new-contributor t-combinatorics	109/0	Mathlib.lean,Mathlib/Combinatorics/Enumerative/Polya.lean	2	2	['IvanRenison', 'github-actions']	awainverse assignee:awainverse	13-21021 13 days ago	31-15035 1 month ago	31-15071 31 days
31178	morrison-daniel author:morrison-daniel	feat(LinearAlgebra/Multilinear): basis for multilinear maps	Adds a basis for MulilinearMap given bases for the domain and codomain. This PR builds upon work started in #25141 toward #11155. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import new-contributor t-algebra label:t-algebra$	567/10	Mathlib.lean,Mathlib/LinearAlgebra/DFinsupp/PiTensorProduct.lean,Mathlib/LinearAlgebra/DirectSum/Finsupp.lean,Mathlib/LinearAlgebra/DirectSum/PiTensorProduct.lean,Mathlib/LinearAlgebra/Multilinear/Basic.lean,Mathlib/LinearAlgebra/Multilinear/Basis.lean,Mathlib/LinearAlgebra/Multilinear/DFinsupp.lean,Mathlib/LinearAlgebra/Multilinear/DirectSum.lean,Mathlib/LinearAlgebra/Multilinear/Finsupp.lean,Mathlib/LinearAlgebra/Multilinear/Pi.lean	10	n/a	['github-actions']	nobody	11-30887 11 days ago	unknown	unknown
28215	5hv5hvnk author:5hv5hvnk	Draft PR, for Strong and Weak connectivity for Digraphs	strong and weak connectivity in Digraphs --- Should resolve a part of issue #26771 Main additions in the PR: 1. Walks in Digraphs (Walk.lean) - Basic walk structure with start and end vertices - Support for walk operations: append, reverse, length - Support functions: getVert, copy, support 2. Walk Decompositions (WalkDecomp.lean) - takeUntil and dropUntil functions to split walks - rotate operation for loop walks - Theorems relating to walk decomposition properties 3. Subgraphs (subgraph.lean) - Subgraph structure for digraphs - Induced and spanning subgraph predicates - Lattice structure (sup, inf, top, bot) - Coercion to standalone digraphs 4. Paths (Paths.lean) - Trail, Path, Circuit, Cycle definitions - Path structure with no repeating vertices - Theorems relating different path types - Basic connectivity definitions (reachable, weakly/strongly connected) 5. Connectivity (Connected.lean) - Reachability relations and properties - Strong and weak connectivity definitions - Connected component types: - StronglyConnectedComponent - WeaklyConnectedComponent - ConnectedComponent - Component properties and equivalence relations --> [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-combinatorics awaiting-author	1266/0	Mathlib.lean,Mathlib/Combinatorics/Digraph/Connected.lean,Mathlib/Combinatorics/Digraph/Paths.lean,Mathlib/Combinatorics/Digraph/Subgraph.lean,Mathlib/Combinatorics/Digraph/Walk.lean,Mathlib/Combinatorics/Digraph/WalkDecomp.lean	6	3	['github-actions', 'grunweg']	nobody	10-76431 10 days ago	82-52404 2 months ago	12-41939 12 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 awaiting-author	6/0	Mathlib/Analysis/InnerProductSpace/PiL2.lean	1	7	['Ruben-VandeVelde', 'Sebi-Kumar', 'github-actions', 'kckennylau']	urkud assignee:urkud	10-75496 10 days ago	10-75496 10 days ago	82-22614 82 days
29871	zach1502 author:zach1502	feat(Matrix/Transvection): Gauss pivot determinant identity and pivot preservation	This PR adds two lemmas formalizing standard Gaussian pivot identities: * `Matrix.Transvection.listTransvecCol_mul_mul_listTransvecRow_pivot`: After applying the canonical left/right transvection products that clear the last column and row, the pivot (bottom-right) entry of a matrix is unchanged. Marked `@[simp]`. * `Matrix.Transvection.det_eq_detTopLeft_mul_pivot`: If the pivot entry is nonzero, then the determinant of the matrix factors as the determinant of the top-left block times the pivot entry, after performing the canonical transvections. This is the usual Gauss–pivot determinant identity. * Added simple usage tests in `MathlibTest/matrix.lean` to check that the new lemmas are usable by `simp`/`simpa`. --- --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra awaiting-author label:t-algebra$	94/0	Mathlib/LinearAlgebra/Matrix/Transvection.lean,MathlibTest/matrix.lean	2	3	['github-actions', 'riccardobrasca', 'zach1502']	nobody	10-70290 10 days ago	10-70290 10 days ago	42-32522 42 days
30609	FlAmmmmING author:FlAmmmmING	feat(Combinatorics/Enumerative/Catalan): large and small Schröder numbers	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-combinatorics awaiting-author	129/1	Mathlib/Combinatorics/Enumerative/Catalan.lean	1	5	['FlAmmmmING', 'SnirBroshi', 'YaelDillies', 'github-actions', 'plp127']	nobody	10-68341 10 days ago	10-81430 10 days ago	17-66663 17 days
30881	FlAmmmmING author:FlAmmmmING	feat(RingTheory/PowerSeries/Schroder.lean) : Define the generating function for large and small Schroder number	Define the generating function for large and small Schroder number. Main result : Prove some lemmas and the generating function of large Schroder. Todo : Prove the generating function of small Schroder. - depends on: #30609 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor	350/1	Mathlib.lean,Mathlib/Combinatorics/Enumerative/Catalan.lean,Mathlib/RingTheory/PowerSeries/Schroder.lean	3	1	['github-actions']	dwrensha assignee:dwrensha	10-67676 10 days ago	19-69302 19 days ago	19-69291 19 days
26300	igorkhavkine author:igorkhavkine	feat(Analysis/Calculus/FDeriv): continuous differentiability from continuous partial derivatives on an open domain in a product space	If a function `f : E × F → G` is continuously differentiable, then its partial derivatives along `E` and `F` are also continuous. The non-trivial converse implication holds when the partial derivatives are continuous on an open domain, and they can be added together to give the total derivative of `f`. See this [#mathlib4 > Partial derivatives @ 💬](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Partial.20derivatives/near/520995477) and the containing thread for some discussion. The PR creates a new import (`Mathlib.Analysis.Calculus.FDeriv.Partial`), where other results about partial derivatives could go in the future. --- this is the migration of #25304 to the PR-from-fork workflow - [x] depends on: #25564 - [x] depends on: #26273 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-analysis awaiting-author WIP	468/0	Mathlib.lean,Mathlib/Analysis/Calculus/FDeriv/Partial.lean,Mathlib/Analysis/Normed/Operator/BoundedLinearMaps.lean	3	20	['YaelDillies', 'agjftucker', 'github-actions', 'igorkhavkine', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'sgouezel']	sgouezel assignee:sgouezel	10-52035 10 days ago	33-33640 1 month ago	50-22679 50 days
31107	rudynicolop author:rudynicolop	feat(Data/Multiset): add Multiset filter and bind lemmas	Add basic lemmas equating `Multiset` `filter`, `filterMap`, `join`, and `bind` operations. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data new-contributor	67/2	Mathlib/Data/Multiset/Bind.lean,Mathlib/Data/Multiset/Filter.lean	2	7	['Ruben-VandeVelde', 'github-actions', 'rudynicolop']	nobody	10-19739 10 days ago	14-30436 14 days ago	14-30474 14 days
30391	rudynicolop author:rudynicolop	feat(Data/List): list splitting definitions and lemmas	This PR continues the work from #24395. Original PR: https://github.com/leanprover-community/mathlib4/pull/24395	t-data new-contributor	154/2	Mathlib/Data/List/Perm/Lattice.lean,Mathlib/Data/List/TakeDrop.lean	2	7	['BoltonBailey', 'github-actions', 'rudynicolop']	nobody	10-19227 10 days ago	35-27608 1 month ago	35-27644 35 days
30158	nicolaviolette author:nicolaviolette	feat: combinatorics simplegraph basic	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-combinatorics awaiting-author	9/4	Mathlib/Combinatorics/SimpleGraph/Basic.lean	1	3	['b-mehta', 'github-actions']	b-mehta assignee:b-mehta	10-3420 10 days ago	10-3420 10 days ago	31-69826 31 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 awaiting-author label:t-algebra$	88/0	Mathlib.lean,Mathlib/Algebra/MvPolynomial/Irreducible.lean	2	5	['alreadydone', 'github-actions', 'mbkybky']	alreadydone assignee:alreadydone	9-59811 9 days ago	9-59811 9 days ago	109-22535 109 days
27229	WilliamCoram author:WilliamCoram	feat(GroupTheory/DoubleCoset): multiple lemmas	From FLT --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-group-theory FLT new-contributor	88/0	Mathlib/GroupTheory/DoubleCoset.lean	1	31	['Ruben-VandeVelde', 'WilliamCoram', 'github-actions', 'kim-em', 'mariainesdff', 'mathlib4-merge-conflict-bot']	mariainesdff assignee:mariainesdff	9-58319 9 days ago	10-49263 10 days ago	103-1403 103 days
29758	SnirBroshi author:SnirBroshi	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	33/4	Mathlib/RingTheory/RootsOfUnity/Complex.lean	1	7	['Ruben-VandeVelde', 'SnirBroshi', 'chrisflav', 'github-actions', 'kckennylau']	chrisflav assignee:chrisflav	9-38227 9 days ago	9-38240 9 days ago	55-44103 55 days
31243	FlAmmmmING author:FlAmmmmING	feat(Mathlib/Combinatorics/SimpleGraph/Planar.lean): Define the planar graph in mathlib	--- [![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/SimpleGraph/Planar.lean	2	5	['SnirBroshi', 'github-actions']	nobody	9-36816 9 days ago	10-12005 10 days ago	10-12042 10 days
30637	strihanje01 author:strihanje01	feat(Combinatorics/SetFamily/Lindstrom): Lindstrom's theorem for subfamilies with equal unions	add Lindstrom's theorem and its strengthening for equal intersections --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-combinatorics	210/0	Mathlib.lean,Mathlib/Combinatorics/SetFamily/Lindstrom.lean	2	1	['github-actions']	b-mehta assignee:b-mehta	9-21024 9 days ago	27-48292 27 days ago	27-48336 27 days
31011	YuvalFilmus author:YuvalFilmus	feat: properties of Chebyshev polynomials over the reals	Added several properties of the Chebyshev polynomials: - Degrees of T_n, U_n - Leading coefficients of T_n, U_n - Evaluations ofT_n, U_n at the endpoints ±1 - T_n is bounded on [-1, 1], and vice versa - Zeroes of T_n and U_n, and extrema of T_n - Normalized T_n minimizes the maximum absolute value over [-1, 1] for monic polynomials --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor	989/5	Mathlib.lean,Mathlib/Algebra/Polynomial/Roots.lean,Mathlib/Analysis/SpecialFunctions/Arsinh.lean,Mathlib/LinearAlgebra/Lagrange.lean,Mathlib/RingTheory/Polynomial/Chebyshev.lean,Mathlib/RingTheory/Polynomial/ChebyshevReal/Basic.lean,Mathlib/RingTheory/Polynomial/ChebyshevReal/Monic.lean	7	22	['Ruben-VandeVelde', 'YuvalFilmus', 'github-actions', 'plp127']	Vierkantor assignee:Vierkantor	9-21007 9 days ago	16-54702 16 days ago	16-54731 16 days
26039	tsuki8 author:tsuki8	feat(RingTheory/MvPolynomial/{MonomialOrder,Ideal}): leadingTerm	define the leadingTerm and prove some lemmas related to the def `leadingTerm`: the leading term of `f` for the monomial ordering `m` some basic lemmas about leadingTerm including: 1. `leadingTerm_eq_zero_iff` 2. `leadingTerm_image_sdiff_singleton_zero` 3. `leadingTerm_image_insert_zero` 4. `leadingTerm_zero` 5. `leadingTerm_degree_eq` 6. `leadingTerm_degree_eq'` some lemmas about the degree of `f - m.leadingTerm f`: 1. `degree_sub_leadingTerm` 2. `degree_sub_leadingTerm_lt_degree` 3. `degree_sub_leadingTerm_lt_iff` also some lemmas about leading terms and ideals： 1. `span_leadingTerm_sdiff_singleton_zero` 2. `span_leadingTerm_insert_zero` 3. `span_leadingTerm_eq_span_monomial` 4. `span_leadingTerm_eq_span_monomial'` Co-authored-by: Junyu Guo @Hagb --- - [x] depends on: #24361 - [x] depends on: #26148 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-ring-theory large-import new-contributor	142/1	Mathlib/RingTheory/MvPolynomial/Ideal.lean,Mathlib/RingTheory/MvPolynomial/MonomialOrder.lean	2	38	['Hagb', 'chrisflav', 'github-actions', 'kim-em', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	chrisflav assignee:chrisflav	9-13988 9 days ago	9-13988 9 days ago	26-63996 26 days
30214	SnirBroshi author:SnirBroshi	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	8/0	Mathlib/Data/List/Basic.lean	1	5	['SnirBroshi', 'eric-wieser', 'github-actions', 'mathlib4-merge-conflict-bot']	nobody	8-37217 8 days ago	8-37236 8 days ago	40-26384 40 days
31038	rudynicolop author:rudynicolop	feat(Computability/NFA): NFA acceptsFrom definitions and lemmas	This PR defines `NFA.acceptsFrom`, similar to [`DFA.acceptsFrom`](https://leanprover-community.github.io/mathlib4_docs/Mathlib/Computability/DFA.html#DFA.acceptsFrom), and provides helper lemmas. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-computability new-contributor	108/6	Mathlib/Computability/NFA.lean	1	23	['eric-wieser', 'github-actions', 'rudynicolop']	nobody	8-23709 8 days ago	16-23222 16 days ago	16-23271 16 days
30416	SnirBroshi author:SnirBroshi	feat(Logic/Relation): lemmas relating `Relation.Map` and `Function.onFun`	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-logic	32/0	Mathlib/Logic/Relation.lean	1	1	['github-actions']	awainverse assignee:awainverse	7-59127 7 days ago	34-39827 1 month ago	34-42054 34 days
30041	josephmckinsey author:josephmckinsey	feat(Algebra/Order/Floor): generalize mul_floor_div theorems to rings and semirings	Generalize `mul_cast_floor_div_cancel` from `Field` and `Semifield` to `Ring` and `Semiring`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra label:t-algebra$	43/31	Mathlib/Algebra/Order/Floor/Ring.lean,Mathlib/Algebra/Order/Floor/Semifield.lean,Mathlib/Algebra/Order/Floor/Semiring.lean,Mathlib/Analysis/Real/OfDigits.lean	4	11	['Ruben-VandeVelde', 'github-actions', 'josephmckinsey', 'mathlib4-merge-conflict-bot']	joneugster assignee:joneugster	7-52679 7 days ago	7-52701 7 days ago	33-45968 33 days
31263	LiranShaul author:LiranShaul	feat: arbitrary product of injective modules is injective	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import new-contributor t-algebra awaiting-author label:t-algebra$	14/0	Mathlib/Algebra/Module/Injective.lean	1	10	['erdOne', 'github-actions', 'joelriou', 'kbuzzard']	nobody	7-38108 7 days ago	9-34463 9 days ago	0-21724 6 hours
30962	WangYiran01 author:WangYiran01	feat(Combinatorics/Enumerative): add lattice path lemmas and counts	This PR adds definitions and theorems about monotone lattice paths: - Defines `pathCount`, `pathCountFrom`, `SubdiagProp`, and related structures. - Proves closed forms such as `pathCount_eq_closed`. - Adds Dyck/ballot subdiagonal property (`SubdiagProp`). All code builds successfully with `lake build`.	new-contributor t-combinatorics	64/0	Mathlib.lean,Mathlib/Combinatorics/Enumerative/RecLatticePath.lean	2	1	['github-actions']	awainverse assignee:awainverse	7-21033 7 days ago	17-83534 17 days ago	17-83575 17 days
31092	FlAmmmmING author:FlAmmmmING	feat(Algebra/Group/ForwardDiff.lean): Add theorem `sum_shift_eq_fwdDiff_iter`.	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra label:t-algebra$	19/0	Mathlib/Algebra/Group/ForwardDiff.lean	1	9	['FlAmmmmING', 'Ruben-VandeVelde', 'github-actions']	dagurtomas assignee:dagurtomas	7-21027 7 days ago	14-58260 14 days ago	14-58304 14 days
12751	Command-Master author:Command-Master	feat: add lemmas for Nat/Bits, Nat/Bitwise and Nat/Size	Remove `@[simp]` from `Nat.bit_false` and `Nat.bit_true`, as `bit0` and `bit1` are deprecated, and add some lemmas to `Bits`, `Bitwise` and `Size`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data new-contributor merge-conflict	66/7	Mathlib/Data/Nat/Bits.lean,Mathlib/Data/Nat/Bitwise.lean,Mathlib/Data/Nat/Multiplicity.lean,Mathlib/Data/Nat/Size.lean	4	26	['Command-Master', 'Rida-Hamadani', 'Ruben-VandeVelde', 'YaelDillies', 'github-actions', 'jcommelin']	nobody	451-58765 1 year ago	456-75007 1 year ago	54-52408 54 days
9605	davikrehalt author:davikrehalt	feat(Data/Finset & List): Add Lemmas for Sorting and Filtering	This PR includes several useful lemmas to the Data/Finset and Data/List modules in Lean's mathlib: 1. `toFinset_filter` (List): Shows that filtering commutes with toFinset. 2. `toFinset_is_singleton_implies_replicate` (List): Shows a list with a singleton toFinset is a List.replicate. 3. `filter_sort_commute` (Finset): Sorting and filtering can be interchanged in Finsets. 4. `Sorted.filter` (List): A sorted list stays sorted after filtering. 5. `Sorted.append_largest` (List): Appending the largest element keeps a list sorted. 6. `sort_monotone_map` (Finset): Relates sorting of a Finset after mapping to sorting of a list. 7. `sort_insert_largest` (Finset): Sorting a Finset with an inserted largest element. 8. `sort_range` (Finset): Sorting a range in a Finset equals the corresponding range list. 9. ~~`filter_eval_true` (List): Filtering a list with a predicate always true keeps the list unchanged.~~ 10. ~~`filter_eval_false` (List): Filtering with an always-false predicate gives an empty list.~~ 11. ~~`pairwise_concat` (List): Iff condition for Pairwise relation in concatenated lists (similar to pairwise_join).~~ 12. `list_map_toFinset` (Finset): toFinset commutes with map under injection --- - [x] depends on: #15952 This is my first PR to mathlib, so I'm not too familiar with etiquette's and more specifically there are two proofs in the PR which uses aesop, and I am not sure if it's frowned upon. I kept the aesop in there for now as I couldn't construct very short proofs otherwise. The sort_range function proof was suggested in https://leanprover.zulipchat.com/#narrow/stream/113489-new-members/topic/Computing.20Finset.20sort.20of.20Finset.20range/near/410346731 by Ruben Van de Velde. Thanks for your time for improving this PR.	t-data new-contributor merge-conflict please-adopt awaiting-author	71/0	Mathlib/Data/Finset/Basic.lean,Mathlib/Data/Finset/Image.lean,Mathlib/Data/Finset/Sort.lean,Mathlib/Data/List/Sort.lean	4	30	['YaelDillies', 'davikrehalt', 'eric-wieser', 'github-actions', 'jcommelin', 'leanprover-community-mathlib4-bot', 'urkud', 'vihdzp']	YaelDillies assignee:YaelDillies	379-34604 1 year ago	406-3395 1 year ago	12-48560 12 days
14598	Command-Master author:Command-Master	chore: add typeclasses to unify various `add_top`, `add_eq_top`, etc.	Add the four typeclasses `IsTopAbsorbing`, `IsBotAbsorbing`, `NoTopSum`, `NoBotSum`, as additive equivalents for `MulZeroClass` and `NoZeroDivisors`. Add instances of these for `ENNReal`, `WithTop α`, `WithBot α`, `PUnit`, `EReal`, `PartENat`, `Measure`, `Interval` and `Filter`. Also split `Algebra/Order/AddGroupWithTop` to `Algebra/Order/Group/WithTop` and `Algebra/Order/Monoid/WithTop` --- Previous usages of lemmas with quantified names like `WithTop.add_top` have to be changed to just `add_top`. `add_lt_top` is `@[simp]`, in accordance with `ENNReal.add_lt_top` being `@[simp]`. This affects `WithTop.add_lt_top` which previously hadn't been `@[simp]`. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-order t-algebra merge-conflict label:t-algebra$	264/195	Archive/Wiedijk100Theorems/BallotProblem.lean,Mathlib.lean,Mathlib/Algebra/Order/Group/WithTop.lean,Mathlib/Algebra/Order/GroupWithZero/Canonical.lean,Mathlib/Algebra/Order/Interval/Basic.lean,Mathlib/Algebra/Order/Monoid/Unbundled/Basic.lean,Mathlib/Algebra/Order/Monoid/Unbundled/Defs.lean,Mathlib/Algebra/Order/Monoid/Unbundled/WithTop.lean,Mathlib/Algebra/Order/Monoid/WithTop.lean,Mathlib/Algebra/PUnitInstances/Order.lean,Mathlib/Algebra/Polynomial/Degree/Definitions.lean,Mathlib/Algebra/Polynomial/Monic.lean,Mathlib/Algebra/Tropical/Basic.lean,Mathlib/Analysis/Analytic/Meromorphic.lean,Mathlib/Analysis/Normed/Lp/ProdLp.lean,Mathlib/Analysis/NormedSpace/ENorm.lean,Mathlib/Analysis/SpecialFunctions/JapaneseBracket.lean,Mathlib/Analysis/SpecialFunctions/Log/ENNRealLog.lean,Mathlib/Data/ENNReal/Operations.lean,Mathlib/Data/ENat/Basic.lean,Mathlib/Data/Nat/PartENat.lean,Mathlib/Data/Nat/WithBot.lean,Mathlib/Data/Real/EReal.lean,Mathlib/LinearAlgebra/Lagrange.lean,Mathlib/MeasureTheory/Covering/Differentiation.lean,Mathlib/MeasureTheory/Decomposition/Lebesgue.lean,Mathlib/MeasureTheory/Function/ConditionalExpectation/CondexpL1.lean,Mathlib/MeasureTheory/Function/Jacobian.lean,Mathlib/MeasureTheory/Function/L1Space.lean,Mathlib/MeasureTheory/Function/L2Space.lean,Mathlib/MeasureTheory/Function/LpSeminorm/Basic.lean,Mathlib/MeasureTheory/Function/LpSeminorm/TriangleInequality.lean,Mathlib/MeasureTheory/Function/LpSpace.lean,Mathlib/MeasureTheory/Function/StronglyMeasurable/Basic.lean,Mathlib/MeasureTheory/Function/UniformIntegrable.lean,Mathlib/MeasureTheory/Integral/Bochner.lean,Mathlib/MeasureTheory/Integral/MeanInequalities.lean,Mathlib/MeasureTheory/Integral/SetIntegral.lean,Mathlib/MeasureTheory/Integral/VitaliCaratheodory.lean,Mathlib/MeasureTheory/Measure/Hausdorff.lean,Mathlib/MeasureTheory/Measure/Lebesgue/Basic.lean,Mathlib/MeasureTheory/Measure/LevyProkhorovMetric.lean,Mathlib/MeasureTheory/Measure/MeasureSpace.lean,Mathlib/MeasureTheory/Measure/MeasureSpaceDef.lean,Mathlib/MeasureTheory/Measure/Regular.lean,Mathlib/MeasureTheory/Measure/Typeclasses.lean,Mathlib/NumberTheory/Padics/PadicNumbers.lean,Mathlib/Order/Filter/Pointwise.lean,Mathlib/Probability/Kernel/Defs.lean,Mathlib/Probability/Martingale/Convergence.lean,Mathlib/RingTheory/Multiplicity.lean,Mathlib/RingTheory/MvPowerSeries/NoZeroDivisors.lean,Mathlib/RingTheory/UniqueFactorizationDomain.lean,Mathlib/Topology/EMetricSpace/Defs.lean,Mathlib/Topology/MetricSpace/Bounded.lean,Mathlib/Topology/MetricSpace/HausdorffDistance.lean,Mathlib/Topology/MetricSpace/Lipschitz.lean	57	30	['Command-Master', 'YaelDillies', 'github-actions']	nobody	373-5170 1 year ago	373-5170 1 year ago	7-45599 7 days
16885	metinersin author:metinersin	feat(ModelTheory/Complexity): define literals	Defines `FirstOrder.Language.BoundedFormula.IsLiteral` and `FirstOrder.Language.BoundedFormula.simpleNot` - an auxiliary operation that takes the negation of a formula and does some simplification. --- - [x] depends on: #16800 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-logic merge-conflict awaiting-author	148/5	Mathlib/ModelTheory/Complexity.lean,Mathlib/ModelTheory/Equivalence.lean,Mathlib/ModelTheory/Semantics.lean,Mathlib/ModelTheory/Syntax.lean	4	20	['YaelDillies', 'awainverse', 'github-actions', 'mathlib4-dependent-issues-bot', 'metinersin']	nobody	370-47691 1 year ago	370-47691 1 year ago	0-19926 5 hours
13248	hcWang942 author:hcWang942	feat: basic concepts of auction theory	## Description Formalise some core concepts and results in auction theory: this includes definitions for first-price and second-price auctions, as well as several fundamental results and helping lemmas. This is the very first PR of the project formalizing core concepts and results in auction theory. Our group is working on more contributions on the formalization of game theory prefix. Co-authored-by: Ma Jiajun ## Reference Roughgarden, Tim. *Twenty Lectures on Algorithmic Game Theory*. Cambridge University Press, 2020. [Link](https://www.cambridge.org/core/books/twenty-lectures-on-algorithmic-game-theory/A9D9427C8F43E7DAEF8C702755B6D72B) --- - [x] Will depend on #14163 once that PR is merged. The Fintype lemmas introduced by this PR have been added in that PR and will be removed from here once that PR gets merged ## Current plan for formalization of Game Theory The current plan for the formalizing of Game Theory include: #### 1. Auction Theory. 🎉 _(200+ lines, this PR)_ - Essential definitions of Sealed-bid auction, First-price auction and Second-price auction. - First-price auction has no dominant strategy. - Second-price auction has dominant strategy. (Second-price auction is DSIC) #### 2. Mechanism design & Myerson's Lemma. 🎉 (400+ lines, pending for modification to Mathlib Standard) - Mechanism design An allocation rule is implementable if there exists - Dominant Strategy Incentive Compatible (DSIC) payment rule - An allocation rule is monotone if for every bidder’s gain is nondecreasing w.r.t. her/his bid - Myerson's Lemma Implementable ⇔ Monotone In the above case, the DSIC payment rule is unique. #### 3. von Neumann‘s Minimax Theorem. 🎉 (800+ lines, pending for modification to Mathlib Standard) - Equilibrium in zero sum game - Formalization strategy: via Loomis’s theorem. #### 4. Nash Equilibrium. 🎉 (pending for modification to Mathlib Standard) #### 5. Brouwer fixed-point theorem. (Work in Progress) #### 6. More Mechanism design. (Planning)	new-contributor t-logic merge-conflict awaiting-author	204/0	Mathlib.lean,Mathlib/GameTheory/Auction/Basic.lean,docs/references.bib	3	148	['Shreyas4991', 'YaelDillies', 'eric-wieser', 'faenuccio', 'github-actions', 'grunweg', 'hcWang942', 'tb65536', 'urkud', 'vihdzp']	hcWang942 assignee:hcWang942	366-123 1 year ago	unknown	unknown
19125	yhtq author:yhtq	feat: add theorems to transfer `IsGalois` between pairs of fraction rings	feat: add theorems to transfer `IsGalois` between pairs of fraction rings. - [x] depends on: #18404 - [x] depends on: #19124 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra merge-conflict label:t-algebra$	121/0	Mathlib.lean,Mathlib/FieldTheory/Galois/IsFractionRing.lean,Mathlib/RingTheory/Localization/FractionRing.lean	3	3	['github-actions', 'mathlib4-dependent-issues-bot', 'tb65536']	nobody	336-22540 11 months ago	342-57963 11 months ago	0-4534 1 hour
17739	Aaron1011 author:Aaron1011	feat(Topology/Order/DenselyOrdered): prove Not (IsOpen) for intervals	Prove that Iic/Ici/Ioc/Ico/Icc intervals are not open in densely ordered topologies with no min/max element --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-topology merge-conflict awaiting-author	27/0	Mathlib/Topology/Order/DenselyOrdered.lean	1	8	['github-actions', 'vihdzp']	nobody	302-44552 9 months ago	302-44552 9 months ago	0-4704 1 hour
15711	znssong author:znssong	feat(Combinatorics/SimpleGraph): Some lemmas about walk, cycle and Hamiltonian cycle	--- These lemmas are separated from the `meow-sister/BondyChvatal` branch and will be needed for the proof of the Bondy-Chvátal theorem. - [x] depends on: #15536 - [x] depends on: #16294	new-contributor t-combinatorics merge-conflict awaiting-author	407/3	Mathlib/Combinatorics/SimpleGraph/Finite.lean,Mathlib/Combinatorics/SimpleGraph/Hamiltonian.lean,Mathlib/Combinatorics/SimpleGraph/Path.lean,Mathlib/Combinatorics/SimpleGraph/Walk.lean	4	22	['Rida-Hamadani', 'YaelDillies', 'github-actions', 'mathlib4-dependent-issues-bot', 'znssong']	nobody	301-63638 9 months ago	301-63638 9 months ago	9-13962 9 days
18629	tomaz1502 author:tomaz1502	feat(Computability.Timed): Formalization of runtime complexity of List.merge	This PR adds the formalization of the runtime complexity of the merge function, defined in `Data/List/Sort`. Requires: https://github.com/leanprover-community/mathlib4/pull/15450 References: - Previous PR on mathlib3: https://github.com/leanprover-community/mathlib3/pull/14494/ - First discussion on Zulip: https://leanprover.zulipchat.com/#narrow/stream/113488-general/topic/BSc.20Final.20Project/near/220647062 - Second disussion on Zulip: https://leanprover.zulipchat.com/#narrow/stream/113488-general/topic/Formalization.20of.20Runtime.20Complexity.20of.20Sorting.20Algorithms/near/284184450 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-computability new-contributor merge-conflict awaiting-author	186/0	Mathlib.lean,Mathlib/Computability/Timed/InsertionSort.lean,Mathlib/Computability/Timed/Merge.lean	3	2	['github-actions', 'trivial1711']	nobody	301-29557 9 months ago	301-29557 9 months ago	33-11262 33 days
19291	PieterCuijpers author:PieterCuijpers	feat(Algebra/Order/Hom): add quantale homomorphism	Definition of quantale homomorphisms as functions that are both semigroup homomorphisms and complete lattice homomorphisms. --- - [x] depends on: #19810 - [x] depends on: #19811 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra merge-conflict awaiting-author label:t-algebra$	209/0	Mathlib.lean,Mathlib/Algebra/Order/Hom/Quantale.lean,scripts/noshake.json	3	29	['PieterCuijpers', 'YaelDillies', 'github-actions', 'kim-em', 'mathlib4-dependent-issues-bot']	nobody	296-51216 9 months ago	296-51217 9 months ago	36-2255 36 days
20372	jvlmdr author:jvlmdr	feat(MeasureTheory/Function): Add ContinuousLinearMap.bilinearCompLp(L)	Introduce ContinuousLinearMap.bilinearCompLp and bilinearCompLpL. Generalize eLpNorm_le_eLpNorm_mul_eLpNorm theorems to include constant C in bound condition. --- Expect this may be useful for defining tempered distributions from functions in `L^p`. The definitions more or less follow `ContinuousLinearMap.compLp...`. Names are loosely analogous to `ContinuousLinearMap.bilinearComp` and `SchwartzMap.bilinLeftCLM`. Note: I preferred the spelling `hpqr : p⁻¹ + q⁻¹ = r⁻¹` with `f` in `L^p` and `g` in `L^q` to `hpqr : 1 / p = 1 / q + 1 / r`. It's easier to obtain from `ENNReal.IsConjExponent` too. A few questions: - [ ] I defined `bilinear{Left,Right}LpL` in addition to `bilinearCompLpL` because `LinearMap.mkContinuous₂` is marked as `noncomputable` and `LinearMap.mkContinuous` is not. Is this worth the extra definitions? (Note: This is not visible in the source due to `noncomputable section`.) - [ ] Should I use `C : ℝ` instead of `C : NNReal` for `eLpNorm_le_eLpNorm_mul_eLpNorm'_of_norm'`? - [ ] Is it going to be painful to have `[Fact (1 ≤ p)] [Fact (1 ≤ q)] [Fact (1 ≤ r)]`? I don't think there's a way to avoid it though. Maybe providing specialized versions for `p.IsConjExponent q` with `L^1`? Naming: - [ ] Is it satisfactory to add a `'` to the `eLpNorm_le_eLpNorm_mul_eLpNorm ` definitions in `CompareExp.lean` where `≤ ‖f x‖ * ‖g x‖` has been replaced with `≤ C * ‖f x‖ * ‖g x‖`? These could replace the existing theorems, although I don't want to break backwards compatibility. There are 5 instances: `eLpNorm_le_eLpNorm_top_mul_eLpNorm'`, `eLpNorm_le_eLpNorm_mul_eLpNorm_top'`, `eLpNorm'_le_eLpNorm'_mul_eLpNorm''`, `eLpNorm_le_eLpNorm_mul_eLpNorm_of_nnnorm'`, `eLpNorm_le_eLpNorm_mul_eLpNorm'_of_norm'` (I'm not sure why the existing theorem `eLpNorm_le_eLpNorm_mul_eLpNorm'_of_norm` has an internal `'`) - [ ] Is `bilinearLeftLpL` a suitable name? Other options: `bilinearCompLpLeftL`, `bilinearCompLeftLpL`, `bilinLeftLpL` (analogous to `SchwartzMap.bilinLeftCLM`) [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-measure-probability merge-conflict	203/40	Mathlib/MeasureTheory/Function/LpSeminorm/CompareExp.lean,Mathlib/MeasureTheory/Function/LpSpace.lean	2	1	['github-actions']	nobody	289-68564 9 months ago	289-68564 9 months ago	27-43617 27 days
17176	arulandu author:arulandu	feat: integrals and integrability with .re	Lemmas for swapping order of .re and integration/integrability. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-measure-probability merge-conflict awaiting-author	49/0	Mathlib/MeasureTheory/Function/L1Space.lean,Mathlib/MeasureTheory/Integral/IntegrableOn.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral.lean,Mathlib/MeasureTheory/Integral/SetIntegral.lean	4	30	['EtienneC30', 'arulandu', 'github-actions', 'loefflerd']	nobody	288-42997 9 months ago	288-42997 9 months ago	9-73631 9 days
19943	AlexLoitzl author:AlexLoitzl	feat(Computability): Add Chomsky Normal Form Grammar and translation	- Define Chomsky normal form grammars - Add language-preserving translation between context-free grammars and Chomsky normal form grammars Co-authored-by: Martin Dvorak martin.dvorak@matfyz.cz --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-computability new-contributor merge-conflict awaiting-author	3151/0	Mathlib.lean,Mathlib/Computability/ChomskyNormalForm/Basic.lean,Mathlib/Computability/ChomskyNormalForm/EmptyElimination.lean,Mathlib/Computability/ChomskyNormalForm/LengthRestriction.lean,Mathlib/Computability/ChomskyNormalForm/TerminalRestriction.lean,Mathlib/Computability/ChomskyNormalForm/Translation.lean,Mathlib/Computability/ChomskyNormalForm/UnitElimination.lean,Mathlib/Computability/ContextFreeGrammar.lean	8	59	['AlexLoitzl', 'YaelDillies', 'github-actions', 'kim-em', 'madvorak']	nobody	272-59973 8 months ago	272-59973 8 months ago	37-29014 37 days
21269	CharredLee author:CharredLee	(WIP) feat (CategoryTheory/Topos): Add topos theory content	This code contains basic definitions and results in topos theory, including the definition of a subobject classifier, power objects, and topoi. It is proved that every topos has exponential objects, i.e. "internal homs". The mathematical content follows chapter IV sections 1-2 of Mac Lane and Moerdijk's text "Sheaves in Geometry and Logic". --- - [x] depends on: #21281 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-category-theory merge-conflict awaiting-author WIP	1269/0	Mathlib.lean,Mathlib/CategoryTheory/Topos/Basic.lean,Mathlib/CategoryTheory/Topos/Classifier.lean,Mathlib/CategoryTheory/Topos/Exponentials.lean,Mathlib/CategoryTheory/Topos/Power.lean	5	10	['CharredLee', 'gio256', 'github-actions', 'joelriou', 'mathlib4-dependent-issues-bot']	nobody	262-26245 8 months ago	262-26245 8 months ago	0-13879 3 hours
14313	grhkm21 author:grhkm21	feat(RepresentationTheory/FdRep): FdRep is a full subcategory of Rep	``` /-- Equivalence between `FDRep` and the full subcategory of finite dimensional `Rep`. -/ def equivFiniteDimensional : FDRep k G ≌ FullSubcategory (fun V : Rep k G ↦ FiniteDimensional k V) ```	new-contributor t-algebra t-category-theory merge-conflict label:t-algebra$	47/8	Mathlib/RepresentationTheory/FDRep.lean	1	19	['github-actions', 'grhkm21', 'joelriou', 'kim-em', 'mathlib-bors']	nobody	258-68571 8 months ago	258-68571 8 months ago	125-12755 125 days
18626	hannahfechtner author:hannahfechtner	feat : define Artin braid groups	Define the Artin braid group on infinitely many strands. Includes a toGroup function which defines a function out of the braid group to any other group (given a function which satisfies the braid relations) (more to come in this file; next up: Artin braid groups on finitely many strands) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra merge-conflict awaiting-author label:t-algebra$	91/0	Mathlib.lean,Mathlib/GroupTheory/SpecificGroups/BraidGroup/Basic.lean	2	22	['github-actions', 'hannahfechtner', 'jcommelin', 'joelriou']	nobody	257-52882 8 months ago	257-52882 8 months ago	15-40648 15 days
21959	BGuillemet author:BGuillemet	feat(Topology/ContinuousMap): Stone-Weierstrass theorem for MvPolynomial	Add the subalgebra of multivariate polynomials and prove it separates points, on the same model as `ContinuousMap/Polynomial.lean`. Prove the Stone-Weierstrass theorem and some variations for multivariate polynomials. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-topology merge-conflict	285/1	Mathlib.lean,Mathlib/Topology/ContinuousMap/MvPolynomial.lean,Mathlib/Topology/ContinuousMap/StoneWeierstrass.lean	3	1	['github-actions']	nobody	253-54585 8 months ago	253-54585 8 months ago	16-76141 16 days
15578	znssong author:znssong	feat(Function): Fixed points of function `f` with `f(x) >= x`	We added some lemmas of fixed points of function `f` with `f(x) >= x`, where `f : α → α` is a function on a finite type `α`. This will be needed in proof of Bondy-Chvátal theorem. --- See also branch `meow-sister/BondyChvatal`. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-analysis merge-conflict awaiting-author	82/0	Mathlib.lean,Mathlib/Dynamics/FixedPoints/Basic.lean,Mathlib/Dynamics/FixedPoints/Increasing.lean	3	32	['Ruben-VandeVelde', 'YaelDillies', 'github-actions', 'urkud', 'vihdzp', 'znssong']	nobody	245-50411 8 months ago	245-50411 8 months ago	29-48368 29 days
21018	markimunro author:markimunro	feat(Data/Matrix): add file with key definitions and theorems about elementary row operations	Prove that each elementary row operation is equivalent to a multiplication by an elementary matrix, has another row operation which inverts it, and that each elementary matrix has a left inverse. This is a very large PR and I understand it will take time. This is my first one and will likely have issues but I will be ready to answer questions/fix them as soon as possible. Co-authored-by: Christopher Lynch --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data new-contributor merge-conflict awaiting-author enhancement	1230/0	Mathlib.lean,Mathlib/Data/Matrix/ElementaryRowOperations.lean,Mathlib/Data/Matrix/GaussianElimination.lean,Mathlib/Data/Matrix/GaussianEliminationOld,Mathlib/Data/Matrix/oldnames,et --hard 18533caba32,lean-toolchain	7	n/a	['chrisflav', 'eric-wieser', 'github-actions', 'j-loreaux', 'markimunro']	nobody	226-85810 7 months ago	unknown	unknown
15212	victorliu5296 author:victorliu5296	feat: Add fundamental theorem of calculus-2 for Banach spaces	add the Mean Value Theorem for Banach spaces to the library and include reference for the theorem statement This theorem states that if `f : X → Y` is differentiable along the line segment from `a` to `b`, then the change in `f` equals the integral of its derivative along this path. This extends the mean value theorem to Banach spaces. This can be used for the eventual proof of the Newton-Kantorovich theorem with 1 constant contained inside the added reference. Here is the discussion on Zulipchat: https://leanprover.zulipchat.com/#narrow/stream/287929-mathlib4/topic/Contributing.20FTC-2.20for.20Banach.20spaces	new-contributor t-measure-probability t-analysis merge-conflict awaiting-author	60/1	Mathlib/MeasureTheory/Integral/FundThmCalculus.lean	1	3	['github-actions', 'hrmacbeth', 'victorliu5296']	nobody	221-80799 7 months ago	221-80799 7 months ago	51-85104 51 days
22701	ctchou author:ctchou	feat(Combinatorics): the Katona circle method	This file formalizes the Katona circle method. From PlainCombi (LeanCamCombi): https://github.com/YaelDillies/LeanCamCombi/blob/master/LeanCamCombi/PlainCombi/KatonaCircle.lean Co-authored-by: Yaël Dillies	new-contributor t-combinatorics merge-conflict	121/0	Mathlib.lean,Mathlib/Combinatorics/KatonaCircle.lean	2	1	['github-actions']	nobody	221-30354 7 months ago	221-30354 7 months ago	30-8337 30 days
21488	imbrem author:imbrem	feat(CategoryTheory/Monoidal): premonoidal categories	Add support for premonoidal categories --- Still want to add support for: - Premonoidal braided/symmetric categories - The monoidal coherence theorem, which I've already ported in my `discretion` library - The `coherence` tactic, which should work fine for premonoidal categories too but wanted to get this in front of reviewers ASAP to make sure my general approach was alright [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-category-theory merge-conflict	900/361	Mathlib/Algebra/Category/ModuleCat/Presheaf/Monoidal.lean,Mathlib/CategoryTheory/Bicategory/End.lean,Mathlib/CategoryTheory/GradedObject/Monoidal.lean,Mathlib/CategoryTheory/Localization/Monoidal.lean,Mathlib/CategoryTheory/Monoidal/Braided/Basic.lean,Mathlib/CategoryTheory/Monoidal/Category.lean,Mathlib/CategoryTheory/Monoidal/Center.lean,Mathlib/CategoryTheory/Monoidal/CoherenceLemmas.lean,Mathlib/CategoryTheory/Monoidal/Discrete.lean,Mathlib/CategoryTheory/Monoidal/End.lean,Mathlib/CategoryTheory/Monoidal/Free/Basic.lean,Mathlib/CategoryTheory/Monoidal/Functor.lean,Mathlib/CategoryTheory/Monoidal/FunctorCategory.lean,Mathlib/CategoryTheory/Monoidal/Mon_.lean,Mathlib/CategoryTheory/Monoidal/Opposite.lean,Mathlib/CategoryTheory/Monoidal/Transport.lean,Mathlib/Tactic/CategoryTheory/Monoidal/Datatypes.lean,Mathlib/Tactic/CategoryTheory/Monoidal/Normalize.lean,Mathlib/Tactic/CategoryTheory/Monoidal/PureCoherence.lean,Mathlib/Tactic/CategoryTheory/MonoidalComp.lean,MathlibTest/StringDiagram.lean	21	9	['YaelDillies', 'github-actions', 'grunweg', 'imbrem', 'kim-em', 'leanprover-community-bot-assistant']	nobody	218-62987 7 months ago	218-62988 7 months ago	58-20339 58 days
20873	vbeffara author:vbeffara	feat(Topology/Covering): path lifting and homotopy lifting	This proves the existence and uniqueness of path and homotopy lifts through covering maps. --- I tried to separate as much of the proof as possible into separate PRs (which are already in Mathlib now), but the proof here relies on a monolithic construction of an explicit lift along a well-chosen subdivision, in `partial_lift`, with associated definitions. Only one standalone lean file added. An older WIP PR #10084 by Junyan Xu @alreadydone proves similar results using a very similar construction for path lifting, with a different argument to obtain continuity for homotopy lifting. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-topology merge-conflict awaiting-author	281/1	Mathlib.lean,Mathlib/Topology/Covering/Basic.lean,Mathlib/Topology/Covering/Lift.lean	3	9	['alreadydone', 'github-actions', 'grunweg', 'vbeffara']	nobody	217-65715 7 months ago	217-65715 7 months ago	55-53553 55 days
20313	thefundamentaltheor3m author:thefundamentaltheor3m	feat(Data/Complex/Exponential): prove some useful results about the complex exponential.	This PR proves two basic results about the complex exponential: * `abs_exp_mul_I (x : ℂ) : abs (Complex.exp (I * x)) = Real.exp (-x.im)` * `one_sub_rexp_re_le_abs_one_sub_cexp (x : ℂ) : 1 - Real.exp x.re ≤ Complex.abs (1 - Complex.exp x)` Both results were proved as part of the sphere packing project. There's a chance they're too specific for mathlib, but I thought they were worth PRing anyway. Would it also be a good idea to tag `abs_exp_mul_I` with `simp`? Feedback/suggestions welcome. Note: `one_sub_rexp_re_le_abs_one_sub_cexp` was proved by Bhavik Mehta @b-mehta --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-analysis merge-conflict	167/141	Mathlib.lean,Mathlib/Analysis/Complex/Basic.lean,Mathlib/Analysis/SpecialFunctions/Log/ERealExp.lean,Mathlib/Analysis/SpecialFunctions/Trigonometric/Chebyshev.lean,Mathlib/Data/Complex/Exponential/Defs.lean,Mathlib/Data/Complex/Exponential/Lemmas.lean,Mathlib/Data/Complex/ExponentialBounds.lean,Mathlib/Tactic/FunProp.lean,MathlibTest/Recall.lean,MathlibTest/positivity.lean	10	12	['b-mehta', 'github-actions', 'kim-em', 'thefundamentaltheor3m', 'trivial1711']	nobody	210-36913 6 months ago	210-36913 6 months ago	25-60481 25 days
20730	kuotsanhsu author:kuotsanhsu	feat(LinearAlgebra/Matrix/SchurTriangulation): prove Schur decomposition/triangulation	`Matrix.schur_triangulation` shows that a matrix over an algebraically closed field is unitarily similar to an upper triangular matrix --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra merge-conflict awaiting-author label:t-algebra$	317/2	Mathlib.lean,Mathlib/LinearAlgebra/Matrix/Block.lean,Mathlib/LinearAlgebra/Matrix/SchurTriangulation.lean,Mathlib/Logic/Equiv/Basic.lean	4	14	['eric-wieser', 'github-actions', 'kim-em', 'kuotsanhsu']	nobody	210-33045 6 months ago	210-33045 6 months ago	13-60072 13 days
23349	BGuillemet author:BGuillemet	feat: add LocallyLipschitzOn.lipschitzOnWith_of_isCompact and two small lemmas about Lipschitz functions	Main feat (in Mathlib/Topology/EMetricSpace/Basic.lean): if a function `f` from an extended pseudometric space to a pseudometric space is locally Lipschitz on a compact subset `s`, then `f` is Lipschitz on `s`. The theorem is true only when the codomain of `f` is a pseudometric space, so it needs imports from Mathlib/Topology/MetricSpace. Other small feat (in Mathlib/Analysis/Calculus/ContDiff/RCLike.lean): a function that is continuously differentiable on an open subset is locally Lipschitz on this subset. --- - [ ] depends on: #22890 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import new-contributor t-topology merge-conflict	59/4	Mathlib/Analysis/Calculus/ContDiff/RCLike.lean,Mathlib/Topology/EMetricSpace/Lipschitz.lean	2	4	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	PatrickMassot assignee:PatrickMassot	170-48083 5 months ago	170-48085 5 months ago	35-30364 35 days
12799	jstoobysmith author:jstoobysmith	feat(LinearAlgebra/UnitaryGroup): Add properties of Special Unitary Group	Add properties of the special unitary group, mirroring the properties of found in Algebra/Star/Unitary.lean. In particular, I add an instance of `specialUnitaryGroup` as a `Group`, `Star`, `InvolutiveStar`, and `StarMul`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra merge-conflict please-adopt awaiting-author label:t-algebra$	78/0	Mathlib/LinearAlgebra/UnitaryGroup.lean	1	8	['chrisflav', 'jcommelin', 'leanprover-community-bot-assistant']	nobody	160-20036 5 months ago	160-20038 5 months ago	9-22007 9 days
20334	miguelmarco author:miguelmarco	feat: allow polyrith to use a local Singular/Sage install	Try to call a local install of Singular (either standalone or inside Sage) to find the witness for polyrith before trying to call the online sage cell server. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-meta merge-conflict awaiting-author	171/48	Mathlib/Tactic/Polyrith.lean,scripts/polyrith_sage.py	2	16	['eric-wieser', 'github-actions', 'hanwenzhu', 'kim-em', 'miguelmarco', 'mkoeppe']	nobody	153-12589 5 months ago	272-76951 8 months ago	27-65384 27 days
25218	kckennylau author:kckennylau	feat(AlgebraicGeometry): Tate normal form of elliptic curves	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-zulip new-contributor t-algebraic-geometry merge-conflict	291/26	Mathlib.lean,Mathlib/AlgebraicGeometry/EllipticCurve/IsomOfJ.lean,Mathlib/AlgebraicGeometry/EllipticCurve/Modular/TateNormalForm.lean,Mathlib/AlgebraicGeometry/EllipticCurve/NormalForms.lean,Mathlib/AlgebraicGeometry/EllipticCurve/VariableChange.lean	5	31	['MichaelStollBayreuth', 'Multramate', 'acmepjz', 'github-actions', 'grunweg', 'kckennylau', 'leanprover-community-bot-assistant']	nobody	132-9350 4 months ago	132-9351 4 months ago	6-51040 6 days
25283	Brian-Nugent author:Brian-Nugent	feat: regular local rings	Adds regular local rings and proves they are integral domains. --- - [ ] depends on: #25280 - [ ] depends on: #25282 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra merge-conflict label:t-algebra$	871/0	.vscode/settings.json,Mathlib.lean,Mathlib/RingTheory/EmbeddingDimension.lean,Mathlib/RingTheory/LocalRingDimension.lean,Mathlib/RingTheory/RegularLocalRing.lean	5	6	['Brian-Nugent', 'github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'yuanyi-350']	nobody	132-9346 4 months ago	132-9346 4 months ago	11-84822 11 days
23990	robertmaxton42 author:robertmaxton42	feat (Types.Colimits): Quot is functorial and colimitEquivQuot is natural	Add `Functor.quotFunctor` to parallel `Functor.sectionsFunctor`, witnessing that `Quot` is functorial; add `colimNatIsoQuotFunctor` to parallel `limNatIsoSectionsFunctor`, witnessing that `colimitEquivQuot` is natural in the diagram $F$. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-category-theory merge-conflict awaiting-author	33/0	Mathlib/CategoryTheory/Limits/Types/Colimits.lean	1	5	['github-actions', 'joelriou', 'leanprover-community-bot-assistant', 'robertmaxton42']	nobody	128-17162 4 months ago	128-17163 4 months ago	8-28043 8 days
10541	Louddy author:Louddy	feat(Algebra/SkewMonoidAlgebra/Basic): add SkewMonoidAlgebra	# Skew Monoid algebras This file presents a skewed version of `Mathlib.Algebra.MonoidAlgebra.Basic`. ## Definition We define `SkewMonoidAlgebra k G := G →₀ k` attached with a skewed convolution product. Here, the product of two elements `f g : SkewMonoidAlgebra k G` is the finitely supported function whose value at `a` is the sum of `f x * (x • g y)` over all pairs `x, y` such that `x * y = a`. This will be used in a later PR to define skew polynomial rings. Co-authored-by: María Inés de Frutos Fernández <[mariaines.dff@gmail.com](mailto:mariaines.dff@gmail.com)> --- - [x] depends on: #15878 - [x] depends on: #19084 - [x] depends on: #22078 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra merge-conflict WIP label:t-algebra$	1624/0	Mathlib.lean,Mathlib/Algebra/Group/InjSurj.lean,Mathlib/Algebra/SkewMonoidAlgebra/Basic.lean,Mathlib/Algebra/SkewMonoidAlgebra/Lift.lean	4	105	['AntoineChambert-Loir', 'Louddy', 'YaelDillies', 'eric-wieser', 'fpvandoorn', 'github-actions', 'mariainesdff', 'mathlib4-dependent-issues-bot', 'mattrobball']	AntoineChambert-Loir assignee:AntoineChambert-Loir	127-64828 4 months ago	127-64830 4 months ago	179-12934 179 days
20029	FrederickPu author:FrederickPu	Allow for Config attributes to be set directly	Allow for Config attributes to be set directly when using initialize_simp_projection as per issue #19895 Basically modified initialize_simp_projection so that the user has the option of specifying a tuple of config option values. Ex: ``` initialize_simp_projection MulEquiv (toFun → apply, invFun → symm_apply) (fullyApplied := false) ``` These config options are then converted into projections. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-meta merge-conflict WIP	34/4	Mathlib/Tactic/Simps/Basic.lean	1	11	['FrederickPu', 'YaelDillies', 'fpvandoorn', 'github-actions', 'leanprover-community-bot-assistant']	nobody	111-36775 3 months ago	111-36776 3 months ago	0-34081 9 hours
11021	jstoobysmith author:jstoobysmith	feat(AlgebraicTopology) : add join of augmented SSets	This pull-request adds the definition of the join of augmented SSets defined as contravariant functors from `WithInitial SimplexCategory` to `Type u`. In addition it shows that the join of two standard augmented SSets is again an augmented SSets. From this the definition of the join of simplicial sets should follow easily. To aid the above theory, an api for `WithInitial SimplexCategory` has been created, with the notion of the `join` and `split` (forming a sort of inverse to join) of objects in this category are defined. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebraic-topology new-contributor merge-conflict WIP	2137/1	.gitignore,Mathlib.lean,Mathlib/AlgebraicTopology/Join.lean,Mathlib/AlgebraicTopology/SimplexCategory.lean,Mathlib/AlgebraicTopology/SimplexCategoryWithInitial.lean,Mathlib/AlgebraicTopology/SimplicialSet.lean	6	47	['github-actions', 'jcommelin']	nobody	105-67934 3 months ago	105-67934 3 months ago	1-20125 1 day
10190	jstoobysmith author:jstoobysmith	feat(AlgebraicTopology): add Augmented Simplex Category	- Added the definition of the category FinLinOrd of finite linear ordered sets. - Added the definition of the augmented simplex category `AugmentedSimplexCategory`, and showed it is the Skeleton of FinLinOrd. - Showed that the category of augmented simplicial objects defined as a comma category is equivalent to the category of functors from `AugmentedSimplexCategory^\op` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebraic-topology new-contributor t-category-theory merge-conflict WIP	720/0	Mathlib.lean,Mathlib/AlgebraicTopology/AugmentedSimplexCategory.lean,Mathlib/AlgebraicTopology/SimplicialObject.lean,Mathlib/Order/Category/FinLinOrd.lean	4	5	['TwoFX', 'YaelDillies', 'joelriou', 'jstoobysmith']	nobody	105-67890 3 months ago	105-67890 3 months ago	7-63215 7 days
9935	jstoobysmith author:jstoobysmith	feat(AlgebraicTopology): add constructors for horns	Added a function that given a simplicial set S and a set of n-1 simplexes satisfying certain conditions, creates a morphism in SSet from a n horn to a simplicial set S. Included also are a series of lemmas and definitions used in this construction. In particular I define a function that takes a m-simplex in a horn, and returns the smallest 'index' of face it factors through, and give a series of lemmas related to this. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebraic-topology new-contributor merge-conflict awaiting-author	462/2	Mathlib/AlgebraicTopology/SimplicialSet.lean	1	15	['YaelDillies', 'jcommelin', 'jstoobysmith', 'kim-em', 'linesthatinterlace']	nobody	105-67291 3 months ago	105-67291 3 months ago	14-58814 14 days
25485	VTrelat author:VTrelat	feat(SetTheory/ZFC/Naturals): define natural numbers in ZFC	Extend the model of ZFC with naturals: - define a set `Nat` of naturals following the usual construction (∅, {∅}, {∅, {∅}}, ...) - define a proper type `ZFNat` representing naturals - add theorems on usual algebraic properties of naturals - provide a recursor and induction schemes to define/prove by induction --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) - [ ] depend on: #25483	t-set-theory new-contributor merge-conflict	2095/0	Mathlib/Data/Set/Prod.lean,Mathlib/SetTheory/ZFC/Basic.lean,Mathlib/SetTheory/ZFC/Booleans.lean,Mathlib/SetTheory/ZFC/Naturals.lean	4	2	['github-actions', 'leanprover-community-bot-assistant']	nobody	101-74111 3 months ago	101-74111 3 months ago	29-51653 29 days
25238	Hagb author:Hagb	feat(Tactic/ComputeDegree): add support for scalar multiplication with different types	It would be able to deal with `a • (X : R[X])` where `a : S` is in a different type `S` with `[SMulZeroClass S R]`. --- - [x] depends on: #25237 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-meta merge-conflict	17/5	Mathlib/Tactic/ComputeDegree.lean,MathlibTest/ComputeDegree.lean	2	3	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	101-74081 3 months ago	101-74081 3 months ago	38-26044 38 days
18646	jxjwan author:jxjwan	feat(RingTheory): isotypic components	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-ring-theory new-contributor merge-conflict	308/0	Mathlib/Order/CompactlyGenerated/Basic.lean,Mathlib/RingTheory/Isotypic.lean,Mathlib/RingTheory/SimpleModule.lean	3	1	['github-actions']	nobody	100-76102 3 months ago	100-76102 3 months ago	20-16585 20 days
20671	thefundamentaltheor3m author:thefundamentaltheor3m	feat(Analysis/Asymptotics/SpecificAsymptotics): Proving that 𝛔ₖ(n) = O(nᵏ⁺¹)	This PR proves a result about the $\sigma_k(n)$ arithmetic function, namely, that it is $O\left(n^{k+1}\right)$. Main theorem: `theorem sigma_asymptotic (k : ℕ) : (fun n ↦ (σ k n : ℝ)) =O[atTop] (fun n ↦ (n ^ (k + 1) : ℝ))` This result was proved as part of the sphere packing project. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import new-contributor t-number-theory merge-conflict awaiting-author	29/0	Mathlib/Analysis/Asymptotics/SpecificAsymptotics.lean	1	3	['b-mehta', 'github-actions', 'mathlib4-merge-conflict-bot']	b-mehta assignee:b-mehta	95-79643 3 months ago	95-79643 3 months ago	9-59130 9 days
25483	VTrelat author:VTrelat	chore(Data/Set/Prod, SetTheory/ZFC/Basic): add theorem prod_subset_of_prod and extend ZFC model	Required by @eric-wieser in #24281 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data new-contributor merge-conflict	103/0	Mathlib/Data/Set/Prod.lean,Mathlib/SetTheory/ZFC/Basic.lean	2	10	['Ruben-VandeVelde', 'VTrelat', 'github-actions', 'leanprover-community-bot-assistant']	nobody	92-61433 3 months ago	132-9340 4 months ago	29-56208 29 days
8102	miguelmarco author:miguelmarco	feat(Tactic): add `unify_denoms` and `collect_signs` tactics	This PR adds four new tactics: - `unify_denoms` tries to put expressions with several divisions in a form with only one division. In the case of fields, it works similarly to `field_simp`, but if the hypothesis about denominators being nonzero are not present, it assumes them, and leaves them as new goals to prove. In that sense, it is an "unsafe" tactic (but can be useful nevertheless, for example when you can't find which exact hypothesis is missing). It also works with expressions of naturals and Euclidean domains, assuming the corresponding hypothesis about the denominators dividing the numerators. - `unify_denoms!` extends `unify_denoms` to work with (in)equalities, assuming also that the denominators, once in normal form, are positive. - `collect_signs` works similarly with expressions using sums and substractions: it tries to put them in a form of one sum minus other sum. In the case of working with naturals, it assumes that we never substract a bigger number from a smaller one. Both are implemented essentially as a macro that combines several rewriting rules. Some new lemmas with the corresponding rules are added. ---	new-contributor t-meta merge-conflict please-adopt modifies-tactic-syntax good first issue	407/0	Mathlib.lean,Mathlib/Algebra/EuclideanDomain/Basic.lean,Mathlib/Tactic.lean,Mathlib/Tactic/CollectSigns.lean,Mathlib/Tactic/UnifyDenoms.lean,MathlibTest/unify_denoms.lean,scripts/noshake.json	7	55	['Paul-Lez', 'YaelDillies', 'github-actions', 'joneugster', 'kbuzzard', 'mathlib4-merge-conflict-bot', 'miguelmarco']	nobody	90-76901 2 months ago	91-257 2 months ago	22-16933 22 days
28150	Equilibris author:Equilibris	chore: clean up proofs typevec proofs	While adding variable universe corecs I found a lot of theorems in typevec that could do with a bit of a clean-up --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data new-contributor merge-conflict	24/26	Mathlib/Data/TypeVec.lean	1	7	['Equilibris', 'alexkeizer', 'github-actions', 'mathlib4-merge-conflict-bot']	nobody	83-26508 2 months ago	83-26509 2 months ago	13-49738 13 days
27403	MoritzBeroRoos author:MoritzBeroRoos	fix: replace probably erroneous usage of ⬝ (with old \cdot) by · (with \centerdot)	Discussion at [zulip](https://leanprover.zulipchat.com/#narrow/channel/270676-lean4/topic/.5Ccdot.20!.3D.20.5Ccenterdot). Currently the abbreviations \cdot and \centerdot resolve to different, with the naked eye nearly undistinguishable symbols (despite the c in cdot surely standing for center..). This pr replaces instances of ⬝ where · was probably meant. All of the replacement is in comments, except for the file bench_summary.lean which is used for priting the github benchmark results. Since this file is about scientific notation of numbers, sure · was meant to be used, not a rectangle. [Related](https://github.com/leanprover-community/mathlib4/pull/27399) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor merge-conflict	195/195	Mathlib/Algebra/ContinuedFractions/Computation/Approximations.lean,Mathlib/Algebra/DirectSum/Idempotents.lean,Mathlib/Algebra/Lie/Derivation/Basic.lean,Mathlib/Algebra/Module/Equiv/Basic.lean,Mathlib/AlgebraicGeometry/EllipticCurve/DivisionPolynomial/Basic.lean,Mathlib/Analysis/Analytic/Constructions.lean,Mathlib/Analysis/CStarAlgebra/CStarMatrix.lean,Mathlib/Analysis/Calculus/ContDiff/Basic.lean,Mathlib/Analysis/Calculus/ContDiff/Bounds.lean,Mathlib/Analysis/Calculus/FDeriv/Symmetric.lean,Mathlib/Analysis/Fourier/FourierTransformDeriv.lean,Mathlib/Analysis/InnerProductSpace/Dual.lean,Mathlib/Analysis/InnerProductSpace/PiL2.lean,Mathlib/Analysis/Normed/Unbundled/InvariantExtension.lean,Mathlib/Analysis/SpecialFunctions/Complex/CircleAddChar.lean,Mathlib/Combinatorics/Configuration.lean,Mathlib/Combinatorics/SimpleGraph/AdjMatrix.lean,Mathlib/Combinatorics/SimpleGraph/LapMatrix.lean,Mathlib/Data/Matrix/Block.lean,Mathlib/Data/Matrix/ConjTranspose.lean,Mathlib/Data/Matrix/Hadamard.lean,Mathlib/Data/Matrix/Mul.lean,Mathlib/Data/Matrix/Notation.lean,Mathlib/Data/Matrix/Reflection.lean,Mathlib/Data/Matrix/RowCol.lean,Mathlib/Data/Matrix/Vec.lean,Mathlib/FieldTheory/PurelyInseparable/PerfectClosure.lean,Mathlib/Geometry/Manifold/GroupLieAlgebra.lean,Mathlib/GroupTheory/Coxeter/Matrix.lean,Mathlib/LinearAlgebra/CrossProduct.lean,Mathlib/LinearAlgebra/Matrix/BilinearForm.lean,Mathlib/LinearAlgebra/Matrix/DotProduct.lean,Mathlib/LinearAlgebra/Matrix/Nondegenerate.lean,Mathlib/LinearAlgebra/Matrix/Orthogonal.lean,Mathlib/LinearAlgebra/Matrix/PosDef.lean,Mathlib/LinearAlgebra/Matrix/SchurComplement.lean,Mathlib/LinearAlgebra/Matrix/SesquilinearForm.lean,Mathlib/LinearAlgebra/Matrix/Trace.lean,Mathlib/LinearAlgebra/Multilinear/Basic.lean,Mathlib/LinearAlgebra/PerfectPairing/Matrix.lean,Mathlib/LinearAlgebra/Projectivization/Constructions.lean,Mathlib/NumberTheory/NumberField/ProductFormula.lean,Mathlib/NumberTheory/SiegelsLemma.lean,Mathlib/RingTheory/DividedPowers/SubDPIdeal.lean,Mathlib/SetTheory/Ordinal/Veblen.lean,Mathlib/Topology/Algebra/Module/Equiv.lean,Mathlib/Topology/Homeomorph/Lemmas.lean,Mathlib/Topology/Instances/Matrix.lean,scripts/bench_summary.lean	49	5	['eric-wieser', 'github-actions', 'grunweg', 'leanprover-community-bot-assistant']	nobody	83-5828 2 months ago	105-68150 3 months ago	7-54661 7 days
27399	MoritzBeroRoos author:MoritzBeroRoos	chore: replace every usage of ⬝ᵥ (with old \cdot) by ·ᵥ (with \centerdot)	Discussion at [zulip](https://leanprover.zulipchat.com/#narrow/channel/270676-lean4/topic/.5Ccdot.20!.3D.20.5Ccenterdot). Currently the abbreviations `\cdot` and `\centerdot` resolve to different, with the naked eye nearly undistinguishable symbols (despite the c in cdot surely standing for `center`..): - `\cdot` gives ⬝ [U+2B1D](https://www.compart.com/en/unicode/U+2B1D) "Black Very Small Square" - `\centerdot` gives · [U+00B7](https://www.compart.com/en/unicode/U+00B7) "Middle Dot" Mathlib mostly uses the `\centerdot` variant, except for the dotProduct notation and some probably unsuspecting people wanting \centerdot but getting \cdot in their comments and 6 uses of a notation using the raw `\cdot` without any subscript at `Mathlib\Topology\Homotopy\Product.lean`. This PR replaces the dot product `⬝ᵥ` with its `\centerdot` counterpart `·ᵥ`. The related PR [here](https://github.com/leanprover/vscode-lean4/pull/639) can then overwrite the `\cdot` abbreviation, to produce the same symbol as the `centerdot` abbreviation does. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor merge-conflict	133/133	Mathlib/Analysis/CStarAlgebra/CStarMatrix.lean,Mathlib/Analysis/InnerProductSpace/PiL2.lean,Mathlib/Combinatorics/Configuration.lean,Mathlib/Combinatorics/SimpleGraph/AdjMatrix.lean,Mathlib/Combinatorics/SimpleGraph/LapMatrix.lean,Mathlib/Data/Matrix/Block.lean,Mathlib/Data/Matrix/ConjTranspose.lean,Mathlib/Data/Matrix/Hadamard.lean,Mathlib/Data/Matrix/Mul.lean,Mathlib/Data/Matrix/Notation.lean,Mathlib/Data/Matrix/Reflection.lean,Mathlib/Data/Matrix/RowCol.lean,Mathlib/Data/Matrix/Vec.lean,Mathlib/LinearAlgebra/CrossProduct.lean,Mathlib/LinearAlgebra/Matrix/BilinearForm.lean,Mathlib/LinearAlgebra/Matrix/DotProduct.lean,Mathlib/LinearAlgebra/Matrix/Nondegenerate.lean,Mathlib/LinearAlgebra/Matrix/Orthogonal.lean,Mathlib/LinearAlgebra/Matrix/PosDef.lean,Mathlib/LinearAlgebra/Matrix/SchurComplement.lean,Mathlib/LinearAlgebra/Matrix/SesquilinearForm.lean,Mathlib/LinearAlgebra/Matrix/Trace.lean,Mathlib/LinearAlgebra/PerfectPairing/Matrix.lean,Mathlib/LinearAlgebra/Projectivization/Constructions.lean,Mathlib/Topology/Instances/Matrix.lean	25	6	['MoritzBeroRoos', 'eric-wieser', 'github-actions', 'leanprover-community-bot-assistant']	nobody	82-54060 2 months ago	105-68151 3 months ago	7-62439 7 days
28708	sjh227 author:sjh227	feat (Data) : edit DoublyStochastic, add Stochastic to matrix	edit DoublyStochastic add Stochastic --- Add the file Stochastic to matrix. Edit DoublyStochastic so that it depends on Stochastic along with a new lemma	t-data new-contributor merge-conflict	249/1	Mathlib.lean,Mathlib/Data/Matrix/DoublyStochastic.lean,Mathlib/Data/Matrix/Stochastic.lean	3	26	['github-actions', 'j-loreaux', 'mathlib4-merge-conflict-bot', 'sjh227']	nobody	78-44772 2 months ago	78-44772 2 months ago	0-78027 21 hours
28623	gilesgshaw author:gilesgshaw	feat(Logic/Basic): minor additions and simplification of proofs	Add new theorems and simplify proofs. Specifically, we add the family of related theorems `apply_dite_iff_exists`, `apply_dite_iff_forall`, `apply_ite_iff_and` and `apply_ite_iff_or`. For each other 'family' of theorems in the file that is analogous to the above, we do the following - Simplify proofs where possible, e.g. by appealing to the new theorems - Complete the family, if any of the corresponding four are missing - Rename to ensure consistency with the above pattern ---	new-contributor t-logic merge-conflict	83/55	Archive/Examples/IfNormalization/Result.lean,Archive/Examples/IfNormalization/WithoutAesop.lean,Mathlib/Algebra/ContinuedFractions/Computation/Translations.lean,Mathlib/Algebra/MvPolynomial/Variables.lean,Mathlib/Algebra/Notation/Indicator.lean,Mathlib/LinearAlgebra/Matrix/Rank.lean,Mathlib/Logic/Basic.lean,Mathlib/MeasureTheory/Measure/WithDensity.lean,Mathlib/SetTheory/Ordinal/Notation.lean	9	12	['eric-wieser', 'gilesgshaw', 'github-actions', 'mathlib4-merge-conflict-bot', 'plp127']	awainverse assignee:awainverse	65-60091 2 months ago	65-60092 2 months ago	21-3001 21 days
29574	JarodUW author:JarodUW	Regular local rings are domains	We have added three new files in Mathlib/RingTheory/LocalRing * EmbeddingDimension.lean * LocalRingDimension.lean * RegularLocalRings.lean We have added two lemmas and an instance in Mathlib/RingTheory/LocalRing/RingHom/Basic.lean This work was done by Jarod Alper and Brian Nugent. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-ring-theory new-contributor merge-conflict	910/3	Mathlib.lean,Mathlib/RingTheory/LocalRing/EmbeddingDimension.lean,Mathlib/RingTheory/LocalRing/LocalRingDimension.lean,Mathlib/RingTheory/LocalRing/RegularLocalRings.lean,Mathlib/RingTheory/LocalRing/RingHom/Basic.lean,lake-manifest.json	6	2	['github-actions', 'mathlib4-merge-conflict-bot']	nobody	60-12040 1 month ago	60-12041 1 month ago	3-7974 3 days
29092	zhuyizheng author:zhuyizheng	feat(MeasureTheory): add absolutely continuous functions, FTC and integration by parts	Add the ε-δ definition of absolutely continuous functions on a closed interval in ℝ. Prove Fundamental Theorem of Calculus and integration by parts for absolutely continuous functions. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-measure-probability merge-conflict awaiting-author	1376/0	Mathlib.lean,Mathlib/Analysis/Calculus/Deriv/Slope.lean,Mathlib/MeasureTheory/Function/AbsolutelyContinuous.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral/AbsContFunc.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral/DerivIntegrable.lean,Mathlib/MeasureTheory/Integral/IntervalIntegral/LebesgueDifferetiationThm.lean,Mathlib/Topology/EMetricSpace/BoundedVariation.lean	7	6	['Ruben-VandeVelde', 'fpvandoorn', 'github-actions', 'grunweg', 'mathlib4-merge-conflict-bot']	nobody	46-32190 1 month ago	46-32191 1 month ago	0-24361 6 hours
26178	ppls-nd-prs author:ppls-nd-prs	feat(CategoryTheory/Limits): Fubini for products	We show that the product of products is a product indexed by the sigma type. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-category-theory merge-conflict awaiting-author	17/0	Mathlib/CategoryTheory/Limits/Shapes/Products.lean	1	6	['chrisflav', 'github-actions', 'leanprover-community-bot-assistant', 'ppls-nd-prs', 'robin-carlier']	nobody	45-74335 1 month ago	132-7041 4 months ago	0-47665 13 hours
16773	arulandu author:arulandu	feat(Probability/Distributions): formalize Beta distribution	Formalize Beta distribution, using Gamma distribution as a reference. Added real-valued beta wrapper, in the manner of gamma. Thanks to @EtienneC30 for help with casting real <-> complex. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-measure-probability merge-conflict awaiting-author	286/1	Mathlib.lean,Mathlib/Analysis/SpecialFunctions/Gamma/Beta.lean,Mathlib/Probability/Distributions/Beta.lean	3	50	['EtienneC30', 'arulandu', 'github-actions', 'mathlib4-merge-conflict-bot', 'vihdzp']	arulandu assignee:arulandu	34-49386 1 month ago	36-61856 1 month ago	1-21124 1 day
22657	Xmask19 author:Xmask19	feat: a graph is maximally acyclic iff it is a tree	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-combinatorics merge-conflict	86/0	Mathlib/Combinatorics/SimpleGraph/Acyclic.lean	1	7	['Rida-Hamadani', 'b-mehta', 'github-actions', 'grunweg', 'mathlib4-merge-conflict-bot']	b-mehta assignee:b-mehta	33-29574 1 month ago	33-29575 1 month ago	208-19611 208 days
28126	Sebi-Kumar author:Sebi-Kumar	feat(AlgebraicTopology/FundamentalGroupoid): relate equality in fundamental groupoid to homotopy	Prove the theorem `fromPath_eq_iff_homotopic` which shows that two paths are equal in the fundamental groupoid if and only if they are homotopic. Also add simp lemmas `fromPath_refl`, `fromPath_symm`, and `fromPath_trans`. Together, these allow one to prove two paths are homotopic by transferring to the fundamental groupoid and using the `aesop_cat` tactic. --- I would like to thank Kenny Lau for inspiring this code on Zulip at [#Is there code for X? > Using aesop_cat to prove paths are homotopic](https://leanprover.zulipchat.com/#narrow/channel/217875-Is-there-code-for-X.3F/topic/Using.20aesop_cat.20to.20prove.20paths.20are.20homotopic). Also, I would like to note that I am a newcomer when it comes to contributing to Mathlib, and that this code was written as a part of a formalization project at the University of Western Ontario under the supervision of Chris Kapulkin and Daniel Carranza (which is happening through the Fields Undergraduate Summer Research Program). - [ ] depends on: #28234 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebraic-topology new-contributor merge-conflict awaiting-author	121/141	Mathlib/AlgebraicTopology/FundamentalGroupoid/Basic.lean,Mathlib/AlgebraicTopology/FundamentalGroupoid/FundamentalGroup.lean,Mathlib/AlgebraicTopology/FundamentalGroupoid/InducedMaps.lean,Mathlib/AlgebraicTopology/FundamentalGroupoid/SimplyConnected.lean,Mathlib/CategoryTheory/Groupoid.lean,Mathlib/Topology/Covering.lean,Mathlib/Topology/Homotopy/HomotopyGroup.lean,Mathlib/Topology/Homotopy/Product.lean	8	11	['Sebi-Kumar', 'alreadydone', 'github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot', 'mattrobball']	mattrobball assignee:mattrobball	26-43718 26 days ago	26-43719 26 days ago	14-30316 14 days
28676	sun123zxy author:sun123zxy	feat(NumberTheory/ArithmeticFunction): wrap `Nat.totient` as an `ArithmeticFunction`	This wraps the Euler's totient function `Nat.totient` into a new `ArithmeticFunction` `ϕ`, with some basic identities such as `ϕ * ζ = id` and `μ * id = ϕ.` --- We use the notation `ϕ` to distinguish from `Nat.totient`'s notation `φ`, however this might be controversial. Suggestions are welcome! [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import new-contributor t-number-theory merge-conflict awaiting-author	45/5	Mathlib/NumberTheory/ArithmeticFunction.lean	1	19	['MichaelStollBayreuth', 'SnirBroshi', 'b-mehta', 'eric-wieser', 'github-actions', 'mathlib4-merge-conflict-bot', 'riccardobrasca', 'sun123zxy']	MichaelStollBayreuth assignee:MichaelStollBayreuth	16-79039 16 days ago	16-79039 16 days ago	53-41880 53 days
30299	franv314 author:franv314	feat(Topology/Instances): Cantor set	Prove that the Cantor set has empty interior and the cardinality of the continuum as discussed on [Zulip](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/A.20few.20results.20about.20the.20Cantor.20set/with/543560670) Moves: - Mathlib.Topology.Instances.CantorSet -> Mathlib.Topology.Instances.CantorSet.Basic --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	file-removed new-contributor t-topology merge-conflict awaiting-author	355/2	Mathlib.lean,Mathlib/Topology/Instances/CantorSet/Basic.lean,Mathlib/Topology/Instances/CantorSet/Cardinality.lean,Mathlib/Topology/Instances/CantorSet/Lemmas.lean	4	5	['github-actions', 'grunweg', 'kckennylau', 'mathlib4-merge-conflict-bot']	nobody	16-70769 16 days ago	16-70770 16 days ago	0-2409 40 minutes
22361	rudynicolop author:rudynicolop	feat(Computability/NFA): nfa closure properties	Add the closure properties union, intersection and reversal for NFA. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-zulip t-computability new-contributor merge-conflict awaiting-author	218/2	Mathlib/Computability/Language.lean,Mathlib/Computability/NFA.lean	2	91	['EtienneC30', 'b-mehta', 'ctchou', 'github-actions', 'leanprover-community-bot-assistant', 'meithecatte', 'rudynicolop']	EtienneC30 assignee:EtienneC30	10-11895 10 days ago	178-51845 5 months ago	39-67601 39 days
26901	5hv5hvnk author:5hv5hvnk	feat: a simproc version of `compute_degree`	Wrap `compute_degree` in a simproc for use by simp. Closes #22219. ---	new-contributor awaiting-CI t-meta merge-conflict awaiting-author	198/0	Mathlib.lean,Mathlib/Tactic/Simproc/PolynomialDegree.lean,MathlibTest/polynomial_degree_simproc.lean	3	19	['5hv5hvnk', 'YaelDillies', 'adomani', 'github-actions', 'mathlib4-merge-conflict-bot']	nobody	7-50088 7 days ago	7-50089 7 days ago	2-71043 2 days
15651	TpmKranz author:TpmKranz	feat(Computability/NFA): operations for Thompson's construction	Lays the groundwork for a proof of equivalence of RE and NFA, w.r.t. described language. Actual connection to REs comes later, after the groundwork for the opposite direction has been laid. Third chunk of #12648 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-zulip t-computability new-contributor merge-conflict awaiting-author	307/5	Mathlib/Computability/NFA.lean	1	15	['TpmKranz', 'YaelDillies', 'dupuisf', 'github-actions', 'leanprover-community-bot-assistant', 'meithecatte']	nobody	0-22812 6 hours ago	178-52770 5 months ago	45-84611 45 days
14242	js2357 author:js2357	feat: Prove equivalence of `isDedekindDomain` and `isDedekindDomainDvr`	Prove that `isDedekindDomainDvr` is equivalent to both `isDedekindDomain` and `isDedekindDomainInv`. Specifically, prove `isDedekindDomainDvr A → isDedekindDomainInv A`, because `isDedekindDomain A → isDedekindDomainDvr A` and `IsDedekindDomain A ↔ IsDedekindDomainInv A` are already in Mathlib. - [x] depends on: #14099 - [x] depends on: #14216 - [ ] depends on: #14237 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra merge-conflict blocked-by-other-PR label:t-algebra$	269/1	Mathlib.lean,Mathlib/RingTheory/DedekindDomain/Dvr.lean,Mathlib/RingTheory/FractionalIdeal/LocalizedAtPrime.lean,Mathlib/RingTheory/Localization/Basic.lean	4	2	['github-actions', 'leanprover-community-mathlib4-bot']	nobody	415-44659 1 year ago	415-44659 1 year ago	0-0 0 seconds
16888	metinersin author:metinersin	feat(ModelTheory/Complexity): Define conjunctive and disjunctive normal forms	Define `FirstOrder.Language.BoundedFormula.IsDNF` and `FirstOrder.Language.BoundedFormula.IsCNF`. --- - [ ] depends on: #16887 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-logic merge-conflict blocked-by-other-PR	415/7	Mathlib/ModelTheory/Complexity.lean,Mathlib/ModelTheory/Equivalence.lean,Mathlib/ModelTheory/Syntax.lean	3	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	407-40637 1 year ago	407-40637 1 year ago	0-1045 17 minutes
16887	metinersin author:metinersin	feat(ModelTheory/Complexity): define conjunctive and disjunctive formulas	Defines `FirstOrder.Language.BoundedFormula.IsConjunctive` and `FirstOrder.Language.BoundedFormula.IsDisjunctive`. --- - [ ] depends on: #16885 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-logic merge-conflict blocked-by-other-PR	300/7	Mathlib/ModelTheory/Complexity.lean,Mathlib/ModelTheory/Equivalence.lean,Mathlib/ModelTheory/Syntax.lean	3	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	407-40637 1 year ago	407-40638 1 year ago	0-1299 21 minutes
16889	metinersin author:metinersin	feat(ModelTheory/Complexity): Normal forms	Defines `FirstOrder.Language.BoundedFormula.toDNF` and `FirstOrder.Language.BoundedFormula.toCNF` - given a quantifier-free formula, these construct a semantically equivalent formula in disjunctive normal form and conjunctive normal form, respectively. --- - [ ] depends on: #16888 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-logic merge-conflict blocked-by-other-PR	525/7	Mathlib/ModelTheory/Complexity.lean,Mathlib/ModelTheory/Equivalence.lean,Mathlib/ModelTheory/Syntax.lean	3	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	407-40636 1 year ago	407-40636 1 year ago	0-613 10 minutes
12750	Command-Master author:Command-Master	feat: define Gray code	--- Define binary reflected gray code, both as a permutation of `Nat` and as a permutation of `BitVec n`, and prove some theorems about them. Additionally, remove `@[simp]` from `Nat.bit_false` and `Nat.bit_true`, as `bit0` and `bit1` are deprecated, and add some lemmas to `Bits`, `Bitwise` and `Size`. - [ ] depends on: #12751 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data new-contributor merge-conflict awaiting-author blocked-by-other-PR	226/0	Mathlib.lean,Mathlib/Data/Nat/Bits.lean,Mathlib/Data/Nat/Bitwise.lean,Mathlib/Data/Nat/GrayCode.lean,Mathlib/Data/Nat/Size.lean	5	5	['Rida-Hamadani', 'alreadydone', 'github-actions', 'grunweg', 'leanprover-community-mathlib4-bot']	nobody	389-63294 1 year ago	389-63294 1 year ago	6-8380 6 days
11156	smorel394 author:smorel394	feat(LinearAlgebra/{TensorProductBasis,Dual}): basis and dual of `PiTensorProduct`	Construct a basis of a `PiTensorProduct` of modules given bases of the modules, and relationship between the dual of a `PiTensorProduct` and the `PiTensorProduct` of the duals. Main results: * `Basis.piTensorProduct` (in `LinearAlgebra/TensorProductBasis.lean`): Let `ι` be a `Fintype` and `M` be a family of modules indexed by `ι`. If `b i : κ i → M i` is a basis for every `i` in `ι`, then `fun (p : Π i, κ i) ↦ ⨂ₜ[R] i, b i (p i)` is a basis of `⨂[R] i, M i`. * `PiTensorProduct.dualDistrib` (in `LinearAlgebra/Dual.lean`): The canonical linear map from `⨂[R] i, Dual R (M i)` to `Dual R (⨂[R] i, M i)`, sending `⨂ₜ[R] i, f i` to the composition of `PiTensorProduct.map f` with the linear equivalence `⨂[R] i, R →ₗ R` given by multiplication. * `PiTensorProduct.dualDistribEquiv` (also in `LinearAlgebra/Dual.lean`): A linear equivalence between `⨂[R] i, Dual R (M i)` and `Dual R (⨂[R] i, M i)` when all `M i` are finite free modules. If `f : (i : ι) → Dual R (M i)`, then this equivalence sends `⨂ₜ[R] i, f i` to the composition of `PiTensorProduct.map f` with the natural isomorphism `⨂[R] i, R ≃ R` given by multiplication. - [ ] depends on: #11155 (currently used as the base branch; do not merge without switching it back to `master`!) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import new-contributor t-algebra merge-conflict please-adopt blocked-by-other-PR label:t-algebra$	166/2	Mathlib/LinearAlgebra/DirectSum/Finsupp.lean,Mathlib/LinearAlgebra/Dual.lean,Mathlib/LinearAlgebra/TensorProduct/Basis.lean	3	4	['eric-wieser', 'github-actions', 'leanprover-community-mathlib4-bot']	nobody	318-61371 10 months ago	363-76999 11 months ago	0-0 0 seconds
15720	znssong author:znssong	feat(SimpleGraph): The Bondy-Chvátal theorem	The proof of the Bondy-Chvátal theorem, with Dirac's theorem and Ore's theorem as its corollary. - [x] depends on: #15536 - [ ] depends on: #15711 - [ ] depends on: #15578	new-contributor t-combinatorics merge-conflict blocked-by-other-PR	903/3	Mathlib.lean,Mathlib/Combinatorics/SimpleGraph/BondyChvatal.lean,Mathlib/Combinatorics/SimpleGraph/Finite.lean,Mathlib/Combinatorics/SimpleGraph/Hamiltonian.lean,Mathlib/Combinatorics/SimpleGraph/Path.lean,Mathlib/Combinatorics/SimpleGraph/Walk.lean,Mathlib/Dynamics/FixedPoints/Basic.lean,Mathlib/Dynamics/FixedPoints/Increasing.lean	8	3	['github-actions', 'grunweg', 'leanprover-community-mathlib4-bot']	YaelDillies assignee:YaelDillies	301-63638 9 months ago	301-63638 9 months ago	0-1791 29 minutes
20248	peabrainiac author:peabrainiac	feat(Topology/Compactness): first-countable locally path-connected spaces are delta-generated	Shows that all first-countable locally path-connected spaces are delta-generated (so in particular all normed spaces and convex subsets thereof are), and that delta-generated spaces are equivalently generated by the unit interval or standard simplices. --- - [ ] depends on: #21616 In principle, this should be close to all that's required to show that all simplicial complexes and CW-complexes are delta-generated; I just haven't done it yet because I'm not sure which file to best do it in. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import new-contributor t-topology merge-conflict awaiting-author blocked-by-other-PR	1189/813	Mathlib.lean,Mathlib/Geometry/Manifold/ChartedSpace.lean,Mathlib/Topology/Algebra/Module/LocallyConvex.lean,Mathlib/Topology/Compactness/DeltaGeneratedSpace.lean,Mathlib/Topology/Connected/LocPathConnected.lean,Mathlib/Topology/Connected/PathConnected.lean,Mathlib/Topology/ContinuousOn.lean,Mathlib/Topology/Homotopy/HSpaces.lean,Mathlib/Topology/Path.lean	9	22	['YaelDillies', 'github-actions', 'kbuzzard', 'mathlib4-dependent-issues-bot', 'peabrainiac']	nobody	277-25874 9 months ago	277-25874 9 months ago	39-21495 39 days
14060	YnirPaz author:YnirPaz	feat(SetTheory/Ordinal/Clubs): define club sets and prove basic properties	Create a file where club sets are defined and their basic properties are proven. I also created a new recursion principle for ordinals, bounded recursion. --- - [ ] depends on: #19189 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-logic merge-conflict blocked-by-other-PR	315/3	Mathlib.lean,Mathlib/Order/SuccPred/Limit.lean,Mathlib/SetTheory/Cardinal/Cofinality.lean,Mathlib/SetTheory/Ordinal/Arithmetic.lean,Mathlib/SetTheory/Ordinal/Club.lean,Mathlib/SetTheory/Ordinal/Topology.lean	6	93	['YaelDillies', 'YnirPaz', 'alreadydone', 'dupuisf', 'github-actions', 'mathlib4-dependent-issues-bot', 'vihdzp', 'zeramorphic']	nobody	255-10995 8 months ago	255-10995 8 months ago	92-44198 92 days
15654	TpmKranz author:TpmKranz	feat(Computability): language-preserving maps between NFA and RE	Map REs to NFAs via Thompson's construction and NFAs to REs using GNFAs Last chunk of #12648 --- - [ ] depends on: #15651 - [ ] depends on: #15649 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-zulip t-computability new-contributor merge-conflict blocked-by-other-PR	985/2	Mathlib.lean,Mathlib/Computability/GNFA.lean,Mathlib/Computability/Language.lean,Mathlib/Computability/NFA.lean,Mathlib/Computability/RegularExpressions.lean,Mathlib/Data/FinEnum/Option.lean,docs/references.bib	7	3	['github-actions', 'leanprover-community-mathlib4-bot', 'meithecatte']	nobody	192-30163 6 months ago	192-30168 6 months ago	0-179 2 minutes
26165	oliver-butterley author:oliver-butterley	feat(MeasureTheory.VectorMeasure): add lemma which shows that variation of a `ℝ≥0∞` VectorMeasure is equal to itself	Add a lemma for the variation of a VectorMeasure which tells that if `μ` is `VectorMeasure X ℝ≥0∞` then `variation μ = μ`. Co-authored-by: @yoh-tanimoto - [ ] depends on: #26160 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-measure-probability blocked-by-other-PR	467/0	Mathlib.lean,Mathlib/MeasureTheory/VectorMeasure/Variation/Defs.lean,Mathlib/MeasureTheory/VectorMeasure/Variation/Lemmas.lean	3	1	['github-actions']	nobody	131-77360 4 months ago	131-77916 4 months ago	15-66224 15 days
26168	oliver-butterley author:oliver-butterley	feat(MeasureTheory.VectorMeasure) : variation defined as a supremum is equal to variation defined using the Hahn-Jordan decomposition.	Add `signedMeasure_totalVariation_eq`: if `μ` is a `SignedMeasure` then variation defined as a supremum is equal to variation defined using the Hahn-Jordan decomposition. Co-authored-by: @yoh-tanimoto - [ ] depends on: #26165 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-measure-probability blocked-by-other-PR	680/0	Mathlib.lean,Mathlib/MeasureTheory/VectorMeasure/Variation/Defs.lean,Mathlib/MeasureTheory/VectorMeasure/Variation/Equiv.lean,Mathlib/MeasureTheory/VectorMeasure/Variation/Lemmas.lean	4	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	131-77360 4 months ago	131-77889 4 months ago	15-65390 15 days
26160	oliver-butterley author:oliver-butterley	feat(MeasureTheory.VectorMeasure): add several lemmas which characterize variation	Add the following lemmas concerning variation of a VectorMeasure: * `norm_measure_le_variation`: `‖μ E‖ₑ ≤ variation μ E`. * `variation_neg`: `(-μ).variation = μ.variation`. * `variation_zero`: `(0 : VectorMeasure X V).variation = 0`. * `absolutelyContinuous` Co-authored-by: @yoh-tanimoto - [ ] depends on: #26156 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-measure-probability blocked-by-other-PR	432/0	Mathlib.lean,Mathlib/MeasureTheory/VectorMeasure/Variation/Defs.lean,Mathlib/MeasureTheory/VectorMeasure/Variation/Lemmas.lean	3	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	131-77359 4 months ago	131-77968 4 months ago	15-68781 15 days
10006	jstoobysmith author:jstoobysmith	feat(AlgebraicTopology): homotopy in quasicategories	Defined a homotopy between two 1-simplicies in a quasicategories, and proved the property of being homotopic forms an equivalence relation. --- - [ ] depends on: #9935 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebraic-topology new-contributor merge-conflict awaiting-author blocked-by-other-PR	898/1	Mathlib.lean,Mathlib/AlgebraicTopology/Homotopy.lean,Mathlib/AlgebraicTopology/SimplexCategory.lean,Mathlib/AlgebraicTopology/SimplicialSet.lean	4	3	['joelriou', 'leanprover-community-mathlib4-bot']	nobody	105-67551 3 months ago	105-67551 3 months ago	0-0 0 seconds
25486	VTrelat author:VTrelat	feat(SetTheory/ZFC/Integers): define integers in ZFC	Extend the model of ZFC with integers following the converse direction as for naturals. We first define a type and then build a set. We finally show that both representations have coercions in both direction: - define a proper type `ZFInt` representing integers based on `ZFNat × ZFNat` and following the usual construction of integers - add theorems on usual algebraic properties of integers - define a set `Int` and show that it matches-i.e. that it is isomorphic to-the type `ZFInt` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) - [ ] depends on: #25483 - [ ] depends on: #25485	t-set-theory new-contributor merge-conflict blocked-by-other-PR	2003/0	Mathlib/Data/Set/Prod.lean,Mathlib/SetTheory/ZFC/Basic.lean,Mathlib/SetTheory/ZFC/Booleans.lean,Mathlib/SetTheory/ZFC/Integers.lean	4	3	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	101-74115 3 months ago	101-74115 3 months ago	0-2067 34 minutes
25484	VTrelat author:VTrelat	feat(SetTheory/ZFC/Booleans): define Boolean algebra in ZFC	Extend the model of ZFC with Boolean algebra: - define a set 𝔹 of booleans - define a proper type `ZFBool` representing booleans - add theorems on usual algebraic properties of booleans - provide usual boolean notations like `⊤`, `⊥`, `∧`, `∨`, etc. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) - [ ] depends on: #25483	t-set-theory new-contributor merge-conflict blocked-by-other-PR	619/0	Mathlib/Data/Set/Prod.lean,Mathlib/SetTheory/ZFC/Basic.lean,Mathlib/SetTheory/ZFC/Booleans.lean	3	3	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	101-74106 3 months ago	101-74106 3 months ago	0-1523 25 minutes
28208	Sebi-Kumar author:Sebi-Kumar	feat(Topology): add the definition `foldTrans` to concatenate finite sequences of paths	Add `foldTrans`, which folds the function `Path.trans` across a sequence of paths with compatible endpoints, corresponding to the concatenation of a finite sequence of paths. This is implemented with `Fin.dfoldl` from the Batteries library. Prove basic properties about `foldTrans` (i.e., how it behaves with respect to `Path.refl`, `Path.subpath`, and homotopies). --- To provide additional context, I am new to contributing to Mathlib, and I am doing so as a part of the Fields Undergraduate Summer Research Program at the University of Western Ontario under the supervision of Chris Kapulkin and Daniel Carranza. My goal is to prove that the `n`-sphere is simply connected for `n > 1`, following the proof from Hatcher's "Algebraic Topology." - [ ] depends on: #27261 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-topology blocked-by-other-PR	259/0	Mathlib.lean,Mathlib/Topology/FoldTrans.lean,Mathlib/Topology/Subpath.lean	3	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	95-23892 3 months ago	95-23893 3 months ago	0-2340 39 minutes
28530	nonisomorphiclinearmap author:nonisomorphiclinearmap	feat(Combinatorics/SimplicialComplex/Topology): add standard simplices and geometric realisation (colimit + functoriality)	Introduce the standard simplex on a finite vertex set and build the geometric realisation \|X\| of a simplicial complex. Prove that \|X\| is the colimit of the face diagram δ_X : X.faces ⥤ TopCat, and define the induced map on realisations \|φ\| : \|X\| ⟶ \|Y\| for a simplicial map φ. Show that the abstract map from colimit functoriality agrees with the concrete push-forward of barycentric coordinates. Package these into a functor SimplicialComplexCat ⥤ TopCat. --- This is our first contribution to mathlib. This work was done as part of the Fields Institute Summer Undergraduate Program on formalization in topological combinatorics. Eventually, we aim to formalize Lovasz's proof of the Kneser Conjecture and this lays the groundwork to do this. We would like to acknowledge the Fields Institute for Research in Mathematical Sciences for their sponsorship. We would also like to thank our supervisors, Professor Chris Kapulkin and Mr. Daniel Carranza, for their guidance and support throughout this project. I would also like to thank our group members Sebastian Kumar, Tom Lindquist and Quang Minh Nguyen for our fruitful discussions. - [ ] depends on: #28125	new-contributor t-combinatorics blocked-by-other-PR	1826/0	Mathlib.lean,Mathlib/Combinatorics/SimplicialComplex/Basic.lean,Mathlib/Combinatorics/SimplicialComplex/Category.lean,Mathlib/Combinatorics/SimplicialComplex/FacePoset.lean,Mathlib/Combinatorics/SimplicialComplex/Hom.lean,Mathlib/Combinatorics/SimplicialComplex/Topology/GeomReal/Basic.lean,Mathlib/Combinatorics/SimplicialComplex/Topology/GeomReal/Colimit.lean,Mathlib/Combinatorics/SimplicialComplex/Topology/GeomReal/Diagram.lean,Mathlib/Combinatorics/SimplicialComplex/Topology/GeomReal/Functor.lean,Mathlib/Combinatorics/SimplicialComplex/Topology/GeomReal/Map.lean,Mathlib/Combinatorics/SimplicialComplex/Topology/Simplex.lean,Mathlib/Combinatorics/SimplicialComplex/Topology/SimplexMap.lean	12	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	89-29696 2 months ago	89-36273 2 months ago	0-591 9 minutes
28502	gilesgshaw author:gilesgshaw	feat(Logic/Basic): avoid unnecessary uses of choice	Certain proofs are modified to remove a dependence on the axoim of choice --- - [ ] depends on: #28623	new-contributor t-logic merge-conflict awaiting-author blocked-by-other-PR	83/74	Mathlib/Logic/Basic.lean	1	7	['Ruben-VandeVelde', 'eric-wieser', 'gilesgshaw', 'github-actions', 'kim-em', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	87-4739 2 months ago	87-4740 2 months ago	0-35689 9 hours
19582	yu-yama author:yu-yama	feat(GroupExtension/Abelian): define `OfMulDistribMulAction.equivH2`	Mainly defines: - `structure GroupExtension.OfMulDistribMulAction N G [MulDistribMulAction G N]`: group extensions of `G` by `N` where the multiplicative action of `G` on `N` is the conjugation - `structure GroupExtension.OfMulDistribMulActionWithSection N G [MulDistribMulAction G N]`: group extensions with specific choices of sections - `def GroupExtension.OfMulDistribMulAction.equivH2`: a bijection between the equivalence classes of group extensions and $H^2 (G, N)$ --- - [x] depends on: #20802 (split PR: contains changes to the `Defs` file) - [x] depends on: #20998 (split PR: mainly adds the `Basic` file) - [ ] depends on: #26670 (split PR: adds the first part of the `Abelian` file) Here is a relevant TODO in Mathlib: https://github.com/leanprover-community/mathlib4/blob/4e9fa40d7c480937e09cd6e47a591bd6f3b8be42/Mathlib/RepresentationTheory/GroupCohomology/LowDegree.lean#L46-L48 I would appreciate your comments. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra merge-conflict blocked-by-other-PR label:t-algebra$	750/14	Mathlib.lean,Mathlib/GroupTheory/GroupExtension/Abelian.lean,Mathlib/GroupTheory/GroupExtension/Defs.lean,docs/references.bib	4	5	['YaelDillies', 'erdOne', 'github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	84-41247 2 months ago	84-41248 2 months ago	43-26015 43 days
25488	VTrelat author:VTrelat	feat(SetTheory/ZFC/Rationals): define rationals in ZFC	Extend the model of ZFC with rationals: we define a proper type `ZFRat` representing integers based on pairs of `ZFInt` (enforcing the res to be nonzero) and following the usual construction of rationals. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) - [ ] depends on: #25483 - [ ] depends on: #25485 - [ ] depends on: #25486	t-set-theory new-contributor merge-conflict blocked-by-other-PR	2070/0	Mathlib/Data/Set/Prod.lean,Mathlib/SetTheory/ZFC/Basic.lean,Mathlib/SetTheory/ZFC/Booleans.lean,Mathlib/SetTheory/ZFC/Integers.lean,Mathlib/SetTheory/ZFC/Rationals.lean	5	3	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	83-5865 2 months ago	83-5865 2 months ago	0-1808 30 minutes
26413	michaellee94 author:michaellee94	feat(Analysis/ODE/MaximalSolution): Existence of maximal solutions for ODE meeting Picard-Lindelöf conditions	Add existence proof for maximal solution of ODE using Picard-Lindelöf and a uniqueness theorem using Grönwall's lemma. --- - [x] depends on: #26382 - [ ] depends on: #29186 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-analysis merge-conflict awaiting-author blocked-by-other-PR	746/1	Mathlib.lean,Mathlib/Analysis/ODE/MaximalSolution.lean,docs/undergrad.yaml	3	13	['github-actions', 'grunweg', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'winstonyin']	nobody	74-37650 2 months ago	74-37651 2 months ago	0-5139 1 hour
29274	Jlh18 author:Jlh18	feat(CategoryTheory): HasLimits instance on Grpd	- Show that the quotient of a groupoid is a groupoid in `CategoryTheory.Quotient`. - Define the free groupoid on a category in `CategoryTheory.Category.FreeGroupoid` and hence define the free-forgetful adjunction between `Grpd` and `Cat`. - Use the free-forgetful adjunction to show that `Grpd` has all limits in `CategoryTheory.Category.Grpd.Limit`, as a reflective subcategory of `Cat`. - [ ] depends on: #29250[Renamings in Grpd file] - [ ] depends on: #29278[Quotient of a groupoid is a groupoid] - [ ] depends on: #29279[Free forgetful adjunction] --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor blocked-by-other-PR	246/1	Mathlib.lean,Mathlib/CategoryTheory/Category/FreeGroupoid.lean,Mathlib/CategoryTheory/Category/Grpd.lean,Mathlib/CategoryTheory/Groupoid/Grpd/Limit.lean,Mathlib/CategoryTheory/Quotient.lean	5	3	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	45-70257 1 month ago	45-70265 1 month ago	0-340 5 minutes
28718	imbrem author:imbrem	Added chosen finite coproducts	Added basic `ChosenFiniteCoproducts` class, and started porting some of the lemmas about `ChosenFiniteProducts` suitably translated --- This, combined with #20182 modified to use chosen finite coproducts and premonoidal categories (#21488), should be enough for me to formalize strong Elgot categories, and hence a lot of categorical iteration theory for my PhD thesis. Re-done from #21603 to deal with changes in #24399 and #24390 Eventually, if we really want to harmonize approaches, we could introduce an `AddMonoidalCategory` struct and do the analogous to #24399 and #24390 for additive monoidal structure, but that seems like a massive overcomplication for now. It would allow formalizing fun things like rig categories, though. - [ ] depends on: #30150	new-contributor t-category-theory awaiting-author blocked-by-other-PR	290/0	Mathlib.lean,Mathlib/CategoryTheory/ChosenFiniteCoproducts.lean	2	8	['YaelDillies', 'github-actions', 'imbrem', 'mathlib4-dependent-issues-bot', 'robin-carlier']	nobody	41-80863 1 month ago	41-80864 1 month ago	0-24930 6 hours
29282	Jlh18 author:Jlh18	feat(CategoryTheory): HasColimits instance on Grpd	Show that the category of groupoids has all small colimits, as a coreflective subcategory of `Cat`, which has all small colimits. The right adjoint of the forgetful functor is the core functor `CategoryTheory.Core.functor`. - [ ] depends on: #29283 [Core of a category as a functor] --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor merge-conflict blocked-by-other-PR	140/4	Mathlib.lean,Mathlib/AlgebraicTopology/FundamentalGroupoid/InducedMaps.lean,Mathlib/CategoryTheory/Category/Grpd.lean,Mathlib/CategoryTheory/Core.lean,Mathlib/CategoryTheory/Groupoid/Grpd/Colimit.lean,Mathlib/CategoryTheory/Groupoid/Grpd/Core.lean	6	3	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	34-54601 1 month ago	57-71014 1 month ago	0-396 6 minutes
28152	Sebi-Kumar author:Sebi-Kumar	feat(AlgebraicTopology): characterize simply connectedness in terms of loops	Show that a space is simply connected if and only if all loops within that space are homotopic to the constant loop. To be used in a proof that the `n`-sphere is simply connected for `n > 1`. --- This code was written at the University of Western Ontario as a part of the Fields Undergraduate Summer Research Program under the supervision of Chris Kapulkin and Daniel Carranza. - [ ] depends on: #28126 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebraic-topology new-contributor merge-conflict blocked-by-other-PR	37/5	Mathlib/AlgebraicTopology/FundamentalGroupoid/Basic.lean,Mathlib/AlgebraicTopology/FundamentalGroupoid/SimplyConnected.lean	2	3	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	26-43717 26 days ago	26-43717 26 days ago	0-2854 47 minutes
28246	Sebi-Kumar author:Sebi-Kumar	feat(AlgebraicTopology/FundamentalGroupoid): the n-sphere is simply connected for n > 1	Prove that the `n`-dimensional sphere (i.e., the unit sphere centered at the origin in `(n + 1)`-dimensional real Euclidean space) is a simply connected space for `n > 1`. This proof follows Hatcher's "Algebraic Topology"; we first prove a general lemma about decomposing loops and then exploit the fact that non-surjective loops in the sphere are homotopically trivial. Note: To get this file to build, I edited `Mathlib/Tactic/Linter/DirectoryDependency.lean` to remove the restrictions on AlgebraicTopology files importing Geometry, NumberTheory, and SetTheory files. Thank you to those who shared their expertise [here](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Warning.20that.20AlgebraicTopology.20can't.20import.20SetTheory/with/533833638). As I understand it, this is just a short-term solution, so I would appreciate feedback on what to do about this situation. Note: I am unsure where exactly the file `SimplyConnectedSphere.lean` should go or whether that is an appropriate name for the file, so feedback there would be appreciated. --- To provide additional context, this code was written as a part of the Fields Undergraduate Summer Research Program at the University of Western Ontario under the supervision of Chris Kapulkin and Daniel Carranza. - [ ] depends on: #28208 - [ ] depends on: #28198 - [ ] depends on: #28185 - [ ] depends on: #28152 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebraic-topology new-contributor merge-conflict blocked-by-other-PR	639/6	Mathlib.lean,Mathlib/AlgebraicTopology/FundamentalGroupoid/Basic.lean,Mathlib/AlgebraicTopology/FundamentalGroupoid/SimplyConnected.lean,Mathlib/AlgebraicTopology/FundamentalGroupoid/SimplyConnectedSphere.lean,Mathlib/Analysis/InnerProductSpace/PiL2.lean,Mathlib/Tactic/Linter/DirectoryDependency.lean,Mathlib/Topology/FoldTrans.lean,Mathlib/Topology/Path.lean,Mathlib/Topology/Subpath.lean	9	3	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	26-43715 26 days ago	26-43716 26 days ago	0-23 23 seconds
30303	franv314 author:franv314	chore(Topology/Instances): add deprecated module	Add deprecated module to moved Cantor set file. --- - [ ] depends on: #30299 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor merge-conflict blocked-by-other-PR	486/124	Mathlib.lean,Mathlib/Topology/Instances/CantorSet.lean,Mathlib/Topology/Instances/CantorSet/Basic.lean,Mathlib/Topology/Instances/CantorSet/Cardinality.lean,Mathlib/Topology/Instances/CantorSet/Lemmas.lean	5	3	['github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	16-70767 16 days ago	16-70768 16 days ago	0-340 5 minutes
29309	LLaurance author:LLaurance	feat(Combinatorics): any connected graph contains a vertex that leaves the graph preconnected if removed	This shows that any nontrivial connected graph contains a vertex that, when removed, leaves the graph connected. --- - [x] depends on: #30590 - [ ] depends on: #31103 - [x] depends on: #31116 - [ ] depends on : #31118 - [ ] depends on : #31119 - [ ] depends on : #31120 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import new-contributor t-combinatorics awaiting-author blocked-by-other-PR	182/2	Mathlib/Combinatorics/SimpleGraph/Acyclic.lean,Mathlib/Combinatorics/SimpleGraph/Connectivity/Subgraph.lean,Mathlib/Combinatorics/SimpleGraph/Subgraph.lean,Mathlib/Combinatorics/SimpleGraph/Walk.lean	4	56	['LLaurance', 'SnirBroshi', 'YaelDillies', 'github-actions', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	YaelDillies assignee:YaelDillies	12-74123 12 days ago	12-79311 12 days ago	32-22015 32 days

Stale delegated PRs

Number	Author	Title	Description	Labels	+/-	Modified files (first 100)	📝	💬	All users who commented or reviewed	Assignee(s)	Updated	Last status change	total time in review
23213	mattrobball author:mattrobball	chore(RingTheory.Derivation): add a `LinearMapClass` instance	Often we want `simp` to call `map_zero` or `map_add` for a `Derivation`. To find the `ZeroHomClass` or `AddHomClass` instance necessary it starts to climb up the type class hierarchy including looking for a `LinearMapClass` instance which didn't exist. Consequently, sythesis would look in a lot of crazy places trying to summon ring structures on the module or on derivations itself. Here we add the missing `LinearMapClass` instance so that `simp` is more efficient. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra delegated label:t-algebra$	5/3	Mathlib/RingTheory/Derivation/Basic.lean	1	8	['github-actions', 'j-loreaux', 'leanprover-bot', 'mathlib-bors', 'mattrobball']	nobody	189-30861 6 months ago	189-30861 6 months ago	47-39026 47 days
23214	mattrobball author:mattrobball	perf(Module.LinearMap.Defs): deprioritize projections to parents for `SemilinearMapClass`	Trying to figure out if a given type has a `SemilinearMapClass` instance when all we want is an `AddHomClass` or a `MulActionSemiHomClass` can be quite expensive since there are multiple ways to crawl the algebraic hierarchy to generate `LinearMapClass` instances. If these fail, then they fail slowly. We deprioritize the projections from `SemilinearMapClass` to `AddHomClass` and `MulActionSemiHomClass` to make this one of the last choices. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra delegated label:t-algebra$	6/0	Mathlib/Algebra/Module/LinearMap/Defs.lean	1	6	['github-actions', 'j-loreaux', 'leanprover-bot', 'mathlib-bors', 'mattrobball']	nobody	189-30627 6 months ago	189-30627 6 months ago	47-32152 47 days
25473	adomani author:adomani	feat(CI): check that Mathlib files have lean or md extension	Twice recently there have been files with an "intended" `.lean` extension in `Mathlib/`: * #24942, ending in `;lean`; * #25457, ending in `.Lean`. `mk_all` does not add these files to `Mathlib.lean`, since they do not end in `.lean` and this later causes problems. This CI step checks that all files in `Mathlib/` end with `.lean` or `.md`. See #25474 for a test where the new step [correctly fails](https://github.com/leanprover-community/mathlib4/actions/runs/15464097783/job/43532018379?pr=25474). --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	CI delegated	10/0	.github/workflows/lint_and_suggest_pr.yml	1	10	['adomani', 'bryangingechen', 'github-actions', 'grunweg', 'mathlib-bors']	nobody	161-64650 5 months ago	161-65540 5 months ago	0-11212 3 hours
25765	JovanGerb author:JovanGerb	feat(gcongr): lemma for rewriting inside divisibility	TODO: add test to show that we can rewrite using `a ≡ b [ZMOD n]` inside `n ∣ 2 * a + 1`. edit: it's not yet entirely clear if this is the right thing to do. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data delegated	5/0	Mathlib/Data/Int/ModEq.lean	1	3	['fpvandoorn', 'github-actions', 'mathlib-bors']	nobody	153-23087 5 months ago	153-58625 5 months ago	1-19951 1 day
25500	eric-wieser author:eric-wieser	feat: delaborators for metadata	Being able to see these is very important when debugging tactic failures. Probably these could be upstreamed, but I don't think that's a reason not to merge them here first. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import t-meta delegated awaiting-author	75/3	Mathlib/Util/Delaborators.lean,Mathlib/Util/PPOptions.lean,MathlibTest/delaborators.lean	3	18	['JovanGerb', 'Rob23oba', 'eric-wieser', 'github-actions', 'kmill', 'mathlib-bors', 'plp127']	alexjbest assignee:alexjbest	77-49202 2 months ago	77-50084 2 months ago	83-71907 83 days
29798	Cyantain author:Cyantain	feat(FieldTheory/IsIntegrallyClosed): lemma to judge whether an element is integral	In this PR, we proved that an element is integral iff it's root of irreducible polynomial with unit leading coeff, which is an easy way to judge an element is integral or not, such as $\sqrt 5 / 4$, because it's root of $16x^2-5$ with not unit leading coeff, so it's not integral.	new-contributor t-algebra delegated awaiting-author label:t-algebra$	13/0	Mathlib/FieldTheory/Minpoly/IsIntegrallyClosed.lean	1	9	['Ruben-VandeVelde', 'adomani', 'github-actions', 'kckennylau', 'mathlib-bors', 'riccardobrasca']	riccardobrasca assignee:riccardobrasca	31-79783 1 month ago	31-79783 1 month ago	6-29891 6 days
29855	eric-wieser author:eric-wieser	chore(Data/Finset/Sort): lemmas about `0 : Fin _` and `Fin.last _`	We already had these for `⟨0, ⋯⟩` and `⟨k - 1, ⋯⟩`. Moves: - `Finset.orderEmbOfFin_zero` -> `Finset.orderEmbOfFin_mk_zero` - `Finset.orderEmbOfFin_last` -> `Finset.orderEmbOfFin_mk_last` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data t-order easy delegated	17/7	Mathlib/Combinatorics/Enumerative/Composition.lean,Mathlib/Data/Finset/Sort.lean	2	4	['eric-wieser', 'github-actions', 'mathlib-bors', 'ocfnash']	nobody	28-40754 28 days ago	49-72844 1 month ago	3-79002 3 days
25737	robin-carlier author:robin-carlier	feat(AlgebraicTopology/SimplexCategory/GeneratorsRelations/NormalForms): Normal forms for `P_δ`s	We prove that admissible lists indeed provide a normal form for morphisms of satisfying `P_δ`. To this end, we introduce `standardδ`, a construction that takes a list and turn it into a composition of `δ i`s in `SimplexCategoryGenRel`. We then prove that, thanks to the first simplicial identity, composition on the left corresponds to simplicial insertion in the list. This gives existence of a normal form for every morphism satisfying `P_δ`. For unicity, we introduce an auxiliary function `simplicialEvalδ : (List ℕ) → ℕ → ℕ` and show that for admissible lists, it lifts to `ℕ` the `orderHom` attached to `toSimplexCategory.map standardδ`, and that we can recover elements of the list only by looking at values of this function. Part of a series of PR formalising that `SimplexCategoryGenRel` is equivalent to `SimplexCategory`. --- - [x] depends on: #25736 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) --- This PR continues the work from #21746. Original PR: https://github.com/leanprover-community/mathlib4/pull/21746	t-algebraic-topology t-category-theory delegated	182/2	Mathlib/AlgebraicTopology/SimplexCategory/GeneratorsRelations/NormalForms.lean	1	6	['github-actions', 'joelriou', 'mathlib-bors', 'mathlib4-dependent-issues-bot', 'mathlib4-merge-conflict-bot']	nobody	23-60424 23 days ago	24-52140 24 days ago	0-22513 6 hours
30914	eric-wieser author:eric-wieser	feat(Data/Set/NAry): lemmas for `diff`	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data t-order delegated	10/0	Mathlib/Data/Set/NAry.lean	1	2	['github-actions', 'grunweg', 'mathlib-bors']	nobody	18-50512 18 days ago	18-50512 18 days ago	0-56942 15 hours
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 delegated	166/5	Mathlib/SetTheory/ZFC/Basic.lean,Mathlib/SetTheory/ZFC/Ordinal.lean,Mathlib/SetTheory/ZFC/PSet.lean,Mathlib/SetTheory/ZFC/Rank.lean	4	26	['alreadydone', 'b-mehta', 'github-actions', 'leanprover-community-bot-assistant', 'mathlib-bors', 'staroperator', 'vihdzp']	b-mehta assignee:b-mehta	10-1364 10 days ago	10-1364 10 days ago	84-52000 84 days
31444	harahu author:harahu	doc(Probability/Martingale/BorelCantelli): polish docstrings	Fix some typos and inconsistencies in `BorelCantelli`. The issues were found and fixed using Codex. The most substantive change is going from $$f_n := \sum_{k < n} \mathbf{1}_{s_{n + 1}} - \mathbb{P}[s_{n + 1} \mid \mathcal{F}_n]$$ to $$f_n := \sum_{k < n} \big(\mathbf{1}_{s_{k + 1}} - \mathbb{P}[s_{k + 1} \mid \mathcal{F}_k]\big).$$ As far as I can tell, this is more faithful to the contents of the file. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-measure-probability delegated	5/5	Mathlib/Probability/Martingale/BorelCantelli.lean	1	3	['github-actions', 'grunweg', 'mathlib-bors']	nobody	3-59782 3 days ago	3-59782 3 days ago	0-71658 19 hours
30950	jessealama author:jessealama	feat: add AffineEquiv.ofLinearEquiv	Adds a constructor for building affine equivalences from linear equivalences and base points. --- Extracted from #30854. cc @Vierkantor @YaelDillies	t-algebra delegated label:t-algebra$	42/0	Mathlib/LinearAlgebra/AffineSpace/AffineEquiv.lean	1	25	['YaelDillies', 'github-actions', 'j-loreaux', 'jessealama', 'jsm28', 'mathlib-bors']	nobody	1-81642 1 day ago	2-33924 2 days ago	2-37505 2 days
31403	JovanGerb author:JovanGerb	feat(push_neg): tag `not_frequently` and `not_eventually`	This PR add support for `not_frequently` and `not_eventually` in the `push_neg` tactic, and it refactors some proofs using this. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-meta delegated	46/63	Mathlib/Analysis/Analytic/OfScalars.lean,Mathlib/Analysis/Analytic/Order.lean,Mathlib/Analysis/Asymptotics/LinearGrowth.lean,Mathlib/Analysis/Calculus/Deriv/Inverse.lean,Mathlib/Analysis/Complex/OpenMapping.lean,Mathlib/Computability/AkraBazzi/GrowsPolynomially.lean,Mathlib/Dynamics/OmegaLimit.lean,Mathlib/MeasureTheory/Function/ConvergenceInMeasure.lean,Mathlib/MeasureTheory/Integral/Lebesgue/Markov.lean,Mathlib/MeasureTheory/Measure/DiracProba.lean,Mathlib/ModelTheory/Ultraproducts.lean,Mathlib/NumberTheory/Transcendental/Liouville/LiouvilleWith.lean,Mathlib/Order/Filter/Basic.lean,Mathlib/Order/Filter/Prod.lean,Mathlib/Order/Filter/Ultrafilter/Defs.lean,Mathlib/Order/LiminfLimsup.lean,Mathlib/Topology/Instances/ENNReal/Lemmas.lean,Mathlib/Topology/Maps/Basic.lean,Mathlib/Topology/Semicontinuous.lean	19	15	['ADedecker', 'JovanGerb', 'github-actions', 'grunweg', 'mathlib-bors']	nobody	1-53215 1 day ago	2-45348 2 days ago	2-64700 2 days
14712	FR-vdash-bot author:FR-vdash-bot	perf: change instance priority and order about `OfNat`	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	slow-typeclass-synthesis t-algebra merge-conflict delegated label:t-algebra$	49/20	Mathlib/Algebra/Group/Nat.lean,Mathlib/Algebra/Group/ZeroOne.lean,Mathlib/Algebra/Homology/Embedding/Basic.lean,Mathlib/Algebra/Tropical/Basic.lean,Mathlib/Data/BitVec.lean,Mathlib/Data/Nat/Cast/Defs.lean,Mathlib/Data/Rat/Defs.lean,Mathlib/Data/UInt.lean,Mathlib/NumberTheory/ArithmeticFunction.lean	9	24	['FR-vdash-bot', 'MichaelStollBayreuth', 'eric-wieser', 'github-actions', 'j-loreaux', 'leanprover-bot', 'mathlib-bors']	nobody	403-72657 1 year ago	406-9733 1 year ago	20-15089 20 days
19275	eric-wieser author:eric-wieser	fix: if nolint files change, do a full rebuild	Otherwise CI will succeed when removing entries from the file, but fail later when someone changes something unrelated. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict delegated	8/0	lakefile.lean	1	20	['YaelDillies', 'adomani', 'eric-wieser', 'github-actions', 'grunweg', 'mathlib-bors']	nobody	223-59001 7 months ago	223-59001 7 months ago	0-214 3 minutes
17129	joneugster author:joneugster	feat(Tactic/Linter): add unicode linter for unicode variant-selectors	Unicode characters can be followed by one of the two "variant-selectors" `\FE0E` (text) or `\FE0F` (emoji). These appear to the user as a single unicode character and they might copy them by accident. For example `✅️` (`\u2705\uFE0F`), `✅` (`\u2705`) and `✅︎` (`\u2705\uFE0E`) are three variants of the "same" unicode character. The one without variant-selector might display as either emoji or not, depending on the user's device and font. Add unicode linter ensuring variant-selector only appear on specified characters and also ensuring these characters always have the correct variant selector to avoid confusions. Everything flagged by this linter can be fixed fully automatically with `lake exe lint-style --fix` or by commenting `bot fix style` on the PR. --- - tracking PR: #16215 ## Zulip discussions: - https://leanprover.zulipchat.com/#narrow/stream/287929-mathlib4/topic/Whitelist.20for.20Unicode.3F - https://leanprover.zulipchat.com/#narrow/stream/113488-general/topic/Lean.20specific.20font ## Related PRs: - leanprover/lean4#5015 added some emoji-variant selectors to Emojis used in `Lean` itself. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import t-linter merge-conflict delegated awaiting-author	245/14	Mathlib.lean,Mathlib/GroupTheory/GroupExtension/Defs.lean,Mathlib/Tactic.lean,Mathlib/Tactic/Linter/TextBased.lean,Mathlib/Tactic/Linter/UnicodeLinter.lean,Mathlib/Tactic/Widget/Calc.lean,Mathlib/Tactic/Widget/CongrM.lean,Mathlib/Tactic/Widget/Conv.lean,Mathlib/Tactic/Widget/GCongr.lean,Mathlib/Topology/ContinuousMap/Weierstrass.lean,MathlibTest/LintStyleTextBased.lean	11	25	['YaelDillies', 'adomani', 'github-actions', 'grunweg', 'joneugster', 'kim-em', 'leanprover-community-bot-assistant']	nobody	181-53023 5 months ago	181-53025 5 months ago	82-54712 82 days
13483	adomani author:adomani	feat: automatically replace deprecations	This PR introduces `lake exe update_deprecations` that uses the cache to automatically replace deprecated declarations with the corresponding un-deprecated one. The script handles namespacing, replacing a possibly non-fully-qualified, deprecated name with the fully-qualified non-deprecated name. It is also possible to use ```bash lake exe update_deprecations --mods One.Two.Three,Dd.Ee.Ff ``` to limit the scope of the replacements to the modules `One.Two.Three` and `Dd.Ee.Ff`. This is intended to be a first step in automating updates: combining this with a linter that emits appropriate warnings, the functionality of `lake exe update_deprecations` can be extended to perform more complicated updates. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-meta merge-conflict delegated awaiting-author	306/0	Mathlib.lean,Mathlib/Tactic.lean,Mathlib/Tactic/UpdateDeprecations.lean,MathlibTest/UpdateDeprecations.lean,lakefile.lean,scripts/README.md,scripts/update_deprecations.lean	7	16	['YaelDillies', 'adomani', 'github-actions', 'j-loreaux', 'jcommelin', 'leanprover-community-bot-assistant', 'mathlib-bors', 'sgouezel']	joneugster assignee:joneugster	156-19912 5 months ago	156-19913 5 months ago	34-82472 34 days
17627	hrmacbeth author:hrmacbeth	feat: universal properties of vector bundle constructions	Characterizations for the smoothness of maps into the total spaces of (1) the direct sum of two vector bundles; (2) the pullback of a vector bundle. This gap in the library was exposed by #17358. --- - [x] depends on: #22804 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-differential-geometry merge-conflict delegated	311/9	Mathlib/Data/Bundle.lean,Mathlib/Geometry/Manifold/VectorBundle/Basic.lean,Mathlib/Geometry/Manifold/VectorBundle/Pullback.lean,Mathlib/Topology/FiberBundle/Constructions.lean	4	24	['PatrickMassot', 'github-actions', 'grunweg', 'hrmacbeth', 'j-loreaux', 'leanprover-community-bot-assistant', 'mathlib-bors', 'mathlib4-dependent-issues-bot', 'sgouezel']	grunweg assignee:grunweg	132-10511 4 months ago	132-10511 4 months ago	91-73632 91 days
26911	JovanGerb author:JovanGerb	chore: fix naming of `mono` and `monotone`	The naming convention says: "We use `_mono` for `a ≤ b → f a ≤ f b` and `_anti` for `a ≤ b → f b ≤ f a`, so we also use `_monotone` for `Monotone f`, `_antitone` for `Antitone f`, `_strictMono` for `StrictMono f`, `_strictAnti` for `StrictAnti f`, etc..." This PR swaps `mono`/`anti` and `monotone`/`antitone` where required so that `monotone` refers to `Monotone`, while `mono` refers to a lemma that might be tagged with `@[gcongr]` This PR does not address - `mul_left_monotone` and `mul_right_monotone` are exactly the wrong way around - `monotone_right`/`mono_right` vs `right_monotone`/`right_mono` - `monotone_arcsin` vs `arcsin_monotone` edit: TODO: `ideal_mono` and friends --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict delegated	238/171	Archive/Imo/Imo1962Q1.lean,Archive/Wiedijk100Theorems/AbelRuffini.lean,Archive/Wiedijk100Theorems/SumOfPrimeReciprocalsDiverges.lean,Counterexamples/DiscreteTopologyNonDiscreteUniformity.lean,Mathlib/Algebra/Group/Pointwise/Finset/Basic.lean,Mathlib/Algebra/Group/Pointwise/Set/Basic.lean,Mathlib/Algebra/Order/Field/Basic.lean,Mathlib/Algebra/Order/Group/Basic.lean,Mathlib/Algebra/Order/Group/Finset.lean,Mathlib/Algebra/Order/Group/PosPart.lean,Mathlib/Algebra/Order/GroupWithZero/Unbundled/Basic.lean,Mathlib/Algebra/Order/Monoid/Unbundled/Basic.lean,Mathlib/Algebra/Order/Monoid/Unbundled/Pow.lean,Mathlib/Algebra/Order/ToIntervalMod.lean,Mathlib/Algebra/Polynomial/Degree/CardPowDegree.lean,Mathlib/AlgebraicGeometry/IdealSheaf/Basic.lean,Mathlib/Analysis/Analytic/Composition.lean,Mathlib/Analysis/Convex/Deriv.lean,Mathlib/Analysis/Normed/Order/UpperLower.lean,Mathlib/Analysis/PSeries.lean,Mathlib/Analysis/SpecialFunctions/Pow/Continuity.lean,Mathlib/Analysis/SpecialFunctions/Trigonometric/Basic.lean,Mathlib/Analysis/SpecificLimits/Basic.lean,Mathlib/Analysis/SpecificLimits/FloorPow.lean,Mathlib/Combinatorics/SetFamily/Kleitman.lean,Mathlib/Combinatorics/SimpleGraph/Girth.lean,Mathlib/Combinatorics/SimpleGraph/Regularity/Chunk.lean,Mathlib/Combinatorics/SimpleGraph/Regularity/Lemma.lean,Mathlib/Computability/Ackermann.lean,Mathlib/Data/ENNReal/Inv.lean,Mathlib/Data/ENNReal/Operations.lean,Mathlib/Data/Nat/Choose/Factorization.lean,Mathlib/Data/Real/Pi/Bounds.lean,Mathlib/LinearAlgebra/AffineSpace/AffineMap.lean,Mathlib/MeasureTheory/Constructions/BorelSpace/Basic.lean,Mathlib/MeasureTheory/Constructions/Polish/Basic.lean,Mathlib/MeasureTheory/MeasurableSpace/MeasurablyGenerated.lean,Mathlib/MeasureTheory/OuterMeasure/Operations.lean,Mathlib/NumberTheory/Bertrand.lean,Mathlib/NumberTheory/FermatPsp.lean,Mathlib/NumberTheory/Padics/Hensel.lean,Mathlib/Order/Concept.lean,Mathlib/Order/Filter/AtTopBot/Defs.lean,Mathlib/Order/Fin/Basic.lean,Mathlib/Order/Heyting/Basic.lean,Mathlib/Order/Heyting/Boundary.lean,Mathlib/Order/Heyting/Regular.lean,Mathlib/Order/Hom/Set.lean,Mathlib/Order/Interval/Set/Fin.lean,Mathlib/Order/KrullDimension.lean,Mathlib/Order/UpperLower/Closure.lean,Mathlib/Probability/StrongLaw.lean,Mathlib/RingTheory/DedekindDomain/Different.lean,Mathlib/RingTheory/DedekindDomain/Ideal.lean,Mathlib/RingTheory/FractionalIdeal/Basic.lean,Mathlib/RingTheory/FractionalIdeal/Operations.lean,Mathlib/Topology/EMetricSpace/Lipschitz.lean,Mathlib/Topology/MetricSpace/Antilipschitz.lean,Mathlib/Topology/MetricSpace/Holder.lean	59	8	['JovanGerb', 'bryangingechen', 'github-actions', 'leanprover-community-bot-assistant', 'linesthatinterlace', 'mathlib-bors']	bryangingechen assignee:bryangingechen	125-18226 4 months ago	125-47250 4 months ago	2-60107 2 days
27872	JovanGerb author:JovanGerb	chore(gcongr): clean up imports	This PR removes redundant `gcongr` imports. And when we do import `gcongr`, we now also import the core `@[gcongr]` tags, and also `grw`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import merge-conflict delegated	7/23	Archive/Imo/Imo2019Q4.lean,Mathlib/Algebra/ContinuedFractions/Computation/ApproximationCorollaries.lean,Mathlib/Algebra/ContinuedFractions/Computation/Approximations.lean,Mathlib/Algebra/MvPolynomial/SchwartzZippel.lean,Mathlib/Algebra/Order/BigOperators/Expect.lean,Mathlib/Algebra/Order/CauSeq/Basic.lean,Mathlib/Algebra/Order/Chebyshev.lean,Mathlib/Analysis/Convex/Segment.lean,Mathlib/Analysis/Convex/Star.lean,Mathlib/Combinatorics/Additive/PluenneckeRuzsa.lean,Mathlib/Combinatorics/Enumerative/Catalan.lean,Mathlib/Combinatorics/SetFamily/FourFunctions.lean,Mathlib/Combinatorics/SimpleGraph/Density.lean,Mathlib/Combinatorics/SimpleGraph/Triangle/Basic.lean,Mathlib/Data/Nat/Basic.lean,Mathlib/NumberTheory/FLT/Polynomial.lean,Mathlib/NumberTheory/FermatPsp.lean,Mathlib/Order/Basic.lean,Mathlib/Order/Filter/AtTopBot/Archimedean.lean,Mathlib/Tactic/GCongr/CoreAttrs.lean,Mathlib/Topology/EMetricSpace/Paracompact.lean	21	11	['JovanGerb', 'bryangingechen', 'github-actions', 'grunweg', 'mathlib-bors', 'mathlib4-merge-conflict-bot']	nobody	85-6247 2 months ago	85-6247 2 months ago	4-34325 4 days
22366	kim-em author:kim-em	feat: `check_equalities` tactic for diagnosing defeq problems	The `check_equalities` tactic, which checks the typing of equalities in the goal, reporting discrepancies between the implicit type argument of the equality, and the inferred types of the left and right hand sides, at "instances and reducible" transparency. Reports from this tactic do not necessarily indicate a problem, although typically `simp` should reduce rather than increase the reported discrepancies. `check_equalities` may be useful in diagnosing uses of `erw`.	t-meta merge-conflict delegated	118/3	Mathlib.lean,Mathlib/Tactic.lean,Mathlib/Tactic/Basic.lean,Mathlib/Tactic/CategoryTheory/CheckCompositions.lean,Mathlib/Tactic/CheckEqualities.lean,Mathlib/Tactic/Common.lean,MathlibTest/check_equalities.lean	7	18	['adomani', 'b-mehta', 'eric-wieser', 'github-actions', 'grunweg', 'kim-em', 'mathlib-bors', 'mathlib4-merge-conflict-bot']	nobody	21-80501 21 days ago	21-80502 21 days ago	15-14325 15 days
23600	mattrobball author:mattrobball	perf(Quiver.Basic): make `IsThin` a `class`	It seems problematic that `Quiver.IsThin` is an `abbrev` for (essentially) `Subsingleton`. We turn it in a one-field class. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict delegated	27/21	Mathlib/CategoryTheory/Bicategory/Coherence.lean,Mathlib/CategoryTheory/Category/Preorder.lean,Mathlib/CategoryTheory/Generator/Basic.lean,Mathlib/CategoryTheory/Groupoid/Basic.lean,Mathlib/CategoryTheory/Limits/Shapes/WidePullbacks.lean,Mathlib/CategoryTheory/Limits/SmallComplete.lean,Mathlib/CategoryTheory/Monoidal/Free/Coherence.lean,Mathlib/CategoryTheory/Skeletal.lean,Mathlib/CategoryTheory/Subobject/MonoOver.lean,Mathlib/CategoryTheory/Thin.lean,Mathlib/Combinatorics/Quiver/Basic.lean	11	17	['b-mehta', 'github-actions', 'leanprover-bot', 'mathlib-bors', 'mathlib4-merge-conflict-bot', 'mattrobball']	nobody	17-50098 17 days ago	17-50099 17 days ago	0-5717 1 hour
27180	ADedecker author:ADedecker	feat: quotient of a monoid with zero by a multiplicative congruence	--- My motivation is getting a more conceptual construction of [ValuativeRel.ValueGroupWithZero](https://leanprover-community.github.io/mathlib4_docs/Mathlib/RingTheory/Valuation/ValuativeRel.html#ValuativeRel.ValueGroupWithZero), but I think this is of independent interest. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict delegated label:t-algebra$	141/26	Mathlib.lean,Mathlib/Data/Quot.lean,Mathlib/Data/Setoid/Basic.lean,Mathlib/GroupTheory/Congruence/Defs.lean,Mathlib/GroupTheory/Congruence/GroupWithZero.lean	5	32	['ADedecker', 'eric-wieser', 'github-actions', 'mathlib-bors', 'mathlib4-merge-conflict-bot', 'ocfnash']	ocfnash assignee:ocfnash	13-62343 13 days ago	13-62344 13 days ago	28-12053 28 days
25481	kbuzzard author:kbuzzard	chore: refactor Algebra.TensorProduct.rightAlgebra	The declaration `Algebra.TensorProduct.rightAlgebra` makes `A ⊗[R] B` into a `B`-algebra (here `R` is a `CommSemiring`, `A` is a `Semiring` and an `R`-algebra, and `B` is a `CommSemiring` and an `R`-algebra). It is not an instance because if A = B it causes a diamond. However in the many cases where A isn't B, it can occasionally be useful. However one could imagine that in the many cases where an R-module `M` also isn't `B`, it might occasionally be useful to make `M ⊗[R] B` into a `B`-module (and indeed I am finding this in FLT). With the current definition of `Algebra.TensorProduct.rightAlgebra` this is difficult to do without causing diamonds in the case when `M` happens to be an `R`-algebra (by which I mean "I failed to do this in finite time"). One fix for this is just to redefine `Algebra.TensorProduct.rightAlgebra` so that the `smul` field is ``` smul b ab := TensorProduct.comm _ _ _ (b • (TensorProduct.comm _ _ _ ab)) ``` i.e. literally "swap the product around, use mathlib's instance making `B ⊗[R] A` into a `B`-algebra, and then swap back". Then the same definition can be used to make `M ⊗[R] B` into a `B`-module and on the odd occasion where this point of view is useful, there is no diamond. This is what we do in this PR. After adding one simp lemma there is no breakage at all in mathlib. Furthermore, for those who have observed that we want to build on this algebra instance sometimes and, for example, add instances of the form "if M is finite over R then M ⊗[R] B is finite over B" -- these instances are really easy to add now with this new definition, because you simply pull back the analogous finite left module instance along the isomorphism M ⊗[R] B = B ⊗[R] M. Examples (from FLT, where the right action is put in a scope): ``` scoped instance [Module.Finite R M] : Module.Finite A (M ⊗[R] A) := Module.Finite.equiv (Module.TensorProduct.comm R A M) scoped instance [Module.Free R M] : Module.Free A (M ⊗[R] A) := Module.Free.of_equiv (Module.TensorProduct.comm R A M) ``` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict delegated label:t-algebra$	33/6	Mathlib/RingTheory/TensorProduct/Basic.lean	1	8	['adomani', 'github-actions', 'kbuzzard', 'leanprover-bot', 'mathlib-bors', 'mathlib4-merge-conflict-bot']	adomani assignee:adomani	3-66994 3 days ago	3-66995 3 days ago	56-85445 56 days