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: July 26, 2025 at 22:51 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	360-52637 11 months ago	696-81908 1 year 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	157-838 5 months ago	161-68834 5 months ago	0-16 16 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/)	new-contributor t-analysis awaiting-author WIP help-wanted	411/0	Mathlib/PlaceHolder/ToeplitzHausdorff.lean,Mathlib/PlaceHolder/ToeplitzHausdorff_v2.lean	2	10	['faenuccio', 'ggranberry', 'github-actions']	faenuccio assignee:faenuccio	100-7473 3 months ago	100-7473 3 months ago	4-24257 4 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	70-17061 2 months ago	70-17079 2 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	63-2840 2 months ago	63-2861 2 months ago	0-0 0 seconds
26109	grunweg author:grunweg	feat(workflows): automatically assign reviewers	Once per day, automatically assign all proposed reviewers from the automatic assignment algorithm. --- See [the github documentation](https://docs.github.com/en/rest/issues/assignees?apiVersion=2022-11-28#add-assignees-to-an-issue) for the assignment syntax. Re-done version of #24705: still need to fix the error. TODO: make the workflow write out a script with the calls to make, and call that script instead. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	CI WIP help-wanted	41/0	.github/workflows/autoassign_reviewers.yml	1	1	['github-actions']	bryangingechen assignee:bryangingechen	38-25102 1 month ago	38-25256 1 month ago	0-8 8 seconds
26349	mans0954 author:mans0954	feat(Analysis/SpecialFunctions/Trigonometric/Basic): sin and cos of multiples of π / 3	This PR continues the work from #25009. Original PR: https://github.com/leanprover-community/mathlib4/pull/25009	help-wanted	160/0	Mathlib/Algebra/Order/Monoid/NatCast.lean,Mathlib/Analysis/SpecialFunctions/Trigonometric/Basic.lean,Mathlib/Data/Nat/Cast/Defs.lean,MathlibTest/trigonometry.lean	4	2	['github-actions', 'mans0954']	nobody	24-7662 24 days ago	27-11905 27 days ago	5-42837 5 days
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	360-52641 11 months ago	373-62238 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	360-52638 11 months ago	538-32540 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	360-52637 11 months ago	677-20497 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	360-52637 11 months ago	382-33341 1 year 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	360-52636 11 months ago	530-39625 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	353-40614 11 months ago	353-40614 11 months 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	345-42390 11 months ago	345-42390 11 months ago	0-0 0 seconds
10765	Vierkantor author:Vierkantor	feat(Tactic): `ring` modulo a given characteristic	This PR extends the `ring` tactic with a new config argument `char` which will try to reduce all constant terms modulo the given characteristic. This allows `ring` to prove e.g. `(x + y)^3 = x^3 + y^3` in characteristic 3. This is a simpler and faster way to do so than what we had before: `repeat { ring; reduce_mod_char }` becomes `ring (config := { char := 3 })`. The first step is to split off the required `CharP` definitions, since `Mathlib.Algebra.CharP.Basic` already requires the `ring` tactic. To perform the reduction modulo the given characteristic, I implemented `reduceCast` which reduces a raw integer, and wrapped it in `reduceResult` that takes a `NormNum.Result` for easy use. We need to pass through quite a few parameters into `reduceResult` so maybe it's worth defining a structure, or reusing `Cache` for this. Then it's basically a case of replacing every place where `ring` constructs a numeral with a call to `reduceResult`. Limitations: * `ring` doesn't attempt to detect the characteristic by itself, you need to pass it in explicitly. Trying to infer a `CharP` instance at each point sounds quite expensive. * Since the support for `%` in `NormNum` only exists for integers, I implemented the reduction only when a `Ring` instance is available. It is still sound in the semiring case, just not complete. * We could optimize exponentiation in the specific case where the characteristic `p` is a prime that divides the exponent `n`: `(x + y)^n = x^n + y^n`. I'll leave that to future work. --- - [x] depends on: #12907 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-meta merge-conflict awaiting-author help-wanted	275/108	Mathlib/RingTheory/MvPolynomial/Basic.lean,Mathlib/Tactic/Polyrith.lean,Mathlib/Tactic/Ring/Basic.lean,Mathlib/Tactic/Ring/RingNF.lean,test/ring_mod_char.lean	5	7	['Vierkantor', 'YaelDillies', 'github-actions', 'joneugster', 'leanprover-community-mathlib4-bot']	joneugster assignee:joneugster	318-34493 10 months ago	318-34493 10 months ago	28-28613 28 days
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	252-50777 8 months ago	252-50777 8 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	177-7835 5 months ago	177-7835 5 months ago	101-64856 101 days
12673	grunweg author:grunweg	feat: add ContDiff.lipschitzOnWith	A C¹ function is Lipschitz on each convex compact set. From sphere-eversion. -------- Commits can be reviewed independently. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-analysis merge-conflict awaiting-author help-wanted	30/11	Mathlib/Analysis/Calculus/ContDiff/RCLike.lean	1	6	['Ruben-VandeVelde', 'github-actions', 'grunweg', 'sgouezel']	nobody	100-26770 3 months ago	100-26770 3 months ago	1-7552 1 day
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	72-35690 2 months ago	97-19994 3 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	73	['ah1112', 'alreadydone', 'eric-wieser', 'github-actions', 'leanprover-community-bot-assistant', 'tb65536', 'urkud']	nobody	3-24008 3 days ago	3-24009 3 days ago	0-0 0 seconds

PRs with just a merge conflict

Number	Author	Title	Description	Labels	+/-	Modified files (first 100)	📝	💬	All users who commented or reviewed	Assignee(s)	Updated	Last status change	total time in review
12936	mattrobball author:mattrobball	chore(Quiver.Opposite): make `Quiver.Hom.op/unop` `abbrev`'s	These are wrappers around the constructor and projection for `Opposite Quiver.Hom _ _`. The projection itself is reducible and with structure eta built in to defeq it seems like we might be making Lean work harder than is necessary. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict	39/34	Mathlib/Algebra/Homology/ShortComplex/Homology.lean,Mathlib/Algebra/Homology/ShortComplex/RightHomology.lean,Mathlib/CategoryTheory/Idempotents/Basic.lean,Mathlib/CategoryTheory/Limits/HasLimits.lean,Mathlib/CategoryTheory/Limits/Opposites.lean,Mathlib/CategoryTheory/Opposites.lean,Mathlib/CategoryTheory/Sites/CoverLifting.lean,Mathlib/CategoryTheory/Subobject/Comma.lean,Mathlib/CategoryTheory/Triangulated/Opposite.lean,Mathlib/Combinatorics/Quiver/Basic.lean	10	9	['YaelDillies', 'kim-em', 'leanprover-bot', 'mattrobball']	nobody	360-52641 11 months ago	428-18633 1 year ago	0-0 0 seconds
10721	urkud author:urkud	feat(Order/FunLike): define `PointwiseLE`	- introduce a mixin class `DFunLike.PointwiseLE`, use it to define `DFunLike.instPartialOrder`; - add a generic `DFunLike.orderEmbeddingCoe` - add `DFunLike.PointwiseLE` instances here and there. With this refactor and #13022, I'm going to generalize lemmas like `MeasureTheory.ae_mono` to `OuterMeasureClass`. --- - [x] depends on: #12983 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-logic t-order merge-conflict	123/50	Mathlib.lean,Mathlib/Algebra/Order/Hom/Ring.lean,Mathlib/Data/DFinsupp/Order.lean,Mathlib/Data/Finsupp/Order.lean,Mathlib/Data/FunLike/Basic.lean,Mathlib/Dynamics/Circle/RotationNumber/TranslationNumber.lean,Mathlib/GroupTheory/Congruence.lean,Mathlib/Order/FunLike.lean,Mathlib/Order/Heyting/Hom.lean,Mathlib/Order/Hom/Basic.lean,Mathlib/Order/Hom/Bounded.lean,Mathlib/Order/Hom/CompleteLattice.lean,Mathlib/Topology/Order/Hom/Basic.lean	13	48	['YaelDillies', 'dupuisf', 'leanprover-community-mathlib4-bot', 'urkud']	nobody	360-52639 11 months ago	382-33341 1 year ago	64-12826 64 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-algebra merge-conflict label:t-algebra$	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	360-52638 11 months ago	394-40555 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	360-52638 11 months ago	394-40540 1 year ago	0-0 0 seconds
7875	FR-vdash-bot author:FR-vdash-bot	chore: make `SMulCommClass A A B` and `SMulCommClass A B B` higher priority	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	slow-typeclass-synthesis t-algebra merge-conflict label:t-algebra$	54/48	Mathlib/Algebra/Algebra/Basic.lean,Mathlib/Algebra/Algebra/NonUnitalSubalgebra.lean,Mathlib/Algebra/DirectSum/Algebra.lean,Mathlib/Algebra/Group/Action/Defs.lean,Mathlib/Algebra/Group/Subgroup/Actions.lean,Mathlib/Algebra/Lie/NonUnitalNonAssocAlgebra.lean,Mathlib/Algebra/Module/LinearMap/End.lean,Mathlib/Algebra/MonoidAlgebra/Basic.lean,Mathlib/Algebra/MvPolynomial/Basic.lean,Mathlib/Algebra/Ring/CentroidHom.lean,Mathlib/Algebra/Ring/Subring/Basic.lean,Mathlib/Algebra/Ring/Subsemiring/Basic.lean,Mathlib/Algebra/Star/NonUnitalSubalgebra.lean,Mathlib/Analysis/Complex/UnitDisc/Basic.lean,Mathlib/Analysis/NormedSpace/lpSpace.lean,Mathlib/Data/Matrix/Basic.lean,Mathlib/GroupTheory/GroupAction/Prod.lean,Mathlib/GroupTheory/GroupAction/Ring.lean,Mathlib/GroupTheory/GroupAction/SubMulAction.lean,Mathlib/GroupTheory/MonoidLocalization.lean,Mathlib/GroupTheory/Submonoid/Center.lean,Mathlib/LinearAlgebra/PiTensorProduct.lean,Mathlib/RingTheory/Ideal/Quotient.lean,Mathlib/RingTheory/TensorProduct/Basic.lean,Mathlib/Topology/ContinuousFunction/ContinuousMapZero.lean,Mathlib/Topology/ContinuousFunction/StoneWeierstrass.lean,Mathlib/Topology/ContinuousFunction/ZeroAtInfty.lean	27	15	['FR-vdash-bot', 'Parcly-Taxel', 'jcommelin', 'leanprover-bot']	nobody	360-52637 11 months ago	382-33341 1 year ago	1-47913 1 day
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	360-52637 11 months ago	382-33341 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	360-52636 11 months ago	382-33341 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	360-52636 11 months ago	382-33341 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	346-46181 11 months ago	346-46181 11 months ago	53-73442 53 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/)	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	342-9205 11 months ago	372-30965 1 year ago	2-10495 2 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	342-9026 11 months ago	382-33341 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	342-8885 11 months ago	382-33341 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	342-8784 11 months ago	382-33341 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	341-29938 11 months ago	346-46180 11 months 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	309-18494 10 months ago	309-18494 10 months 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	299-67277 9 months ago	299-67277 9 months 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	290-9682 9 months ago	382-33341 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	262-62743 8 months ago	262-62743 8 months 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	262-61646 8 months ago	262-61646 8 months ago	18-19513 18 days
18806	FR-vdash-bot author:FR-vdash-bot	refactor: deprecate `MulEquivClass`	--- - [x] depends on: #18809 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	84/72	Mathlib/Algebra/Group/Equiv/Basic.lean,Mathlib/Algebra/Group/Units/Equiv.lean,Mathlib/Algebra/GroupWithZero/Hom.lean,Mathlib/Algebra/GroupWithZero/NonZeroDivisors.lean,Mathlib/Algebra/Module/Equiv/Defs.lean,Mathlib/Algebra/Order/Hom/Monoid.lean,Mathlib/Algebra/Prime/Lemmas.lean,Mathlib/Algebra/Ring/Divisibility/Basic.lean,Mathlib/Algebra/Ring/Equiv.lean,Mathlib/Combinatorics/Additive/FreimanHom.lean,Mathlib/RingTheory/Bialgebra/Equiv.lean,Mathlib/RingTheory/Ideal/Norm.lean,Mathlib/RingTheory/Localization/FractionRing.lean,Mathlib/RingTheory/Multiplicity.lean,Mathlib/Topology/Algebra/InfiniteSum/Basic.lean	15	6	['FR-vdash-bot', 'github-actions', 'leanprover-bot', 'mathlib4-dependent-issues-bot', 'vihdzp']	nobody	250-18924 8 months ago	250-18924 8 months ago	4-31794 4 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	242-39498 8 months ago	242-39498 8 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	240-15575 7 months ago	240-15575 7 months ago	4-60621 4 days
18756	FR-vdash-bot author:FR-vdash-bot	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	['FR-vdash-bot', 'github-actions', 'leanprover-bot']	nobody	228-67644 7 months ago	228-67644 7 months ago	31-75259 31 days
19046	j-loreaux author:j-loreaux	feat: define class `SemigroupAction`	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	34/25	Mathlib/Algebra/Category/ModuleCat/Presheaf.lean,Mathlib/Algebra/Category/ModuleCat/Presheaf/Pushforward.lean,Mathlib/Algebra/Group/Action/Defs.lean,Mathlib/Algebra/Group/Action/End.lean,Mathlib/Algebra/Group/Action/Prod.lean,Mathlib/Algebra/Group/Action/TypeTags.lean,Mathlib/Algebra/Polynomial/Laurent.lean,Mathlib/Analysis/Distribution/SchwartzSpace.lean,Mathlib/GroupTheory/CoprodI.lean,Mathlib/LinearAlgebra/FreeModule/IdealQuotient.lean,Mathlib/LinearAlgebra/Matrix/SesquilinearForm.lean	11	7	['alreadydone', 'github-actions', 'j-loreaux', 'leanprover-bot', 'urkud']	nobody	225-29128 7 months ago	225-29129 7 months ago	6-21105 6 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	222-31657 7 months ago	222-31660 7 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	194-28450 6 months ago	194-28450 6 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	192-15480 6 months ago	192-15480 6 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	179-39737 5 months ago	179-39737 5 months ago	27-43617 27 days
18463	vihdzp author:vihdzp	feat(SetTheory/Ordinal/Notation/FundamentalSequence): define type of fundamental sequences	We define `Sequence α` as the type of sequences with length 0, 1, or `ω`, and give a basic API. A subsequent PR will introduce the notion of a (countable and computable) fundamental sequence and establish basic results. The goal of this is to generalize [`ONote.fundamentalSequence`](https://leanprover-community.github.io/mathlib4_docs/Mathlib/SetTheory/Ordinal/Notation.html#ONote.fundamentalSequence) to allow the construction of fundamental sequences for other ordinal notations. --- See [my ordinal notation repository](https://github.com/vihdzp/ordinal-notation/blob/a6fdd7fe7cb521e686ea271902e7e5496f1804d3/OrdinalNotation/Cantor.lean#L1218) for a demonstration of how this API looks in practice. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-set-theory t-order merge-conflict	174/1	Mathlib.lean,Mathlib/SetTheory/Ordinal/Notation/Cantor.lean,Mathlib/SetTheory/Ordinal/Notation/FundamentalSequence.lean	3	19	['YnirPaz', 'b-mehta', 'github-actions', 'vihdzp']	nobody	157-63879 5 months ago	157-63879 5 months ago	52-25108 52 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	153-22715 5 months ago	153-22715 5 months ago	27-75210 27 days
21339	vihdzp author:vihdzp	fix(Data/List/Lex): remove duplicate `List.LE` instance	Mathlib currently duplicates the Lean core instance for `≤` in lists in an incompatible way. We delete this duplicate instance. See [Zulip](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Two.20.60List.2ELE.60.20instances.3F/near/497241115). --- This is a very quick and dirty fix. Core Lean provides all of the theorems we need to prove `≤` forms a linear order, but it provides them in terms of `Std` relation typeclasses which currently see no use in Mathlib. I've added the instances that were required to get the list theorems working. In the future, we really ought to unify the core and Mathlib relation typeclasses. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data merge-conflict	24/22	Mathlib/Data/List/Lex.lean,Mathlib/Data/String/Basic.lean,Mathlib/Topology/Category/Profinite/Nobeling.lean	3	1	['github-actions']	nobody	145-21607 4 months ago	145-21607 4 months ago	16-65973 16 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	143-25758 4 months ago	143-25758 4 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	131-48013 4 months ago	131-48013 4 months ago	10-48025 10 days
21856	vihdzp author:vihdzp	chore(SetTheory/Cardinal/Basic): generalize universes of `sum_le_iSup_lift`	We prove a more general version of the lemma which talks about families `ι → Cardinal.{v}` with `Small.{v} ι`, rather than just families `f : ι → Cardinal.{max u v}` with `ι : Type v`. We keep the old version, as it's seemingly more useful under common circumstances. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-set-theory merge-conflict	16/10	Mathlib/SetTheory/Cardinal/Basic.lean	1	6	['b-mehta', 'github-actions', 'vihdzp']	nobody	130-39247 4 months ago	130-39247 4 months ago	32-26420 32 days
22027	vihdzp author:vihdzp	chore(SetTheory/Ordinal/FixedPoint); review `Ordinal.nfp` API	This PR does the following: - add `iff` variants of various theorems, renaming some in the process - weaken some assumptions slightly - golf throughout --- - [x] depends on: #22017 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-set-theory merge-conflict	64/61	Mathlib/Logic/Equiv/List.lean,Mathlib/SetTheory/Ordinal/FixedPoint.lean	2	3	['github-actions', 'grunweg', 'mathlib4-dependent-issues-bot']	nobody	112-5765 3 months ago	114-59125 3 months ago	43-68322 43 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	111-1527 3 months ago	111-1527 3 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	109-48241 3 months ago	109-67810 3 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	108-34160 3 months ago	108-34161 3 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	108-34158 3 months ago	108-34160 3 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	102-59124 3 months ago	102-59126 3 months ago	55-52030 55 days
13795	FR-vdash-bot author:FR-vdash-bot	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	35	['FR-vdash-bot', 'MichaelStollBayreuth', 'eric-wieser', 'github-actions', 'leanprover-bot', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'mattrobball']	nobody	102-51439 3 months ago	102-51441 3 months ago	52-31623 52 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	102-4017 3 months ago	350-42347 11 months 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	100-8120 3 months ago	100-8120 3 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	95-47034 3 months ago	95-47037 3 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	93-23809 3 months ago	93-23811 3 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	93-12506 3 months ago	93-12507 3 months ago	2-12022 2 days
23621	FR-vdash-bot author:FR-vdash-bot	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	['FR-vdash-bot', 'github-actions', 'grunweg', 'leanprover-bot', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	kbuzzard assignee:kbuzzard	92-12076 3 months ago	unknown	unknown
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	88-16910 2 months ago	88-16911 2 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	84-82456 2 months ago	84-82458 2 months ago	87-51692 87 days
14023	mattrobball author:mattrobball	perf(RingTheory.OreLocalization): make data irreducible	We generally do not want to unfold operations passing through `Quotient` if we can avoid it for performance reasons. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict	43/32	Mathlib/GroupTheory/MonoidLocalization.lean,Mathlib/RingTheory/OreLocalization/Basic.lean,Mathlib/RingTheory/OreLocalization/Ring.lean	3	5	['github-actions', 'grunweg', 'leanprover-bot', 'mattrobball']	nobody	84-54589 2 months ago	392-44412 1 year ago	0-0 0 seconds
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	84-54291 2 months ago	84-54291 2 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	83-29038 2 months ago	83-29039 2 months ago	26-25420 26 days
9273	grunweg author:grunweg	feat: extended charts are local diffeomorphisms on their source	--- TODO: I think this should hold at any interior point - as the inverse of the extended chart, restricted to the interior of its source, will be a local inverse. The analogous result for un-extended charts is shown in #8160. Unresolved questions - are all the tiny API lemmas useful; are any more missing? - do I want similar results for `extChartAt`? (In any case, they are easy to deduce.) - [ ] depends on: #8738 for simplicity [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-differential-geometry merge-conflict	225/12	Mathlib/Geometry/Manifold/ContMDiff/Atlas.lean,Mathlib/Geometry/Manifold/LocalDiffeomorph.lean,Mathlib/Topology/Algebra/Module/Basic.lean	3	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	79-4446 2 months ago	unknown	unknown
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	62-32038 2 months ago	62-32040 2 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	61-37526 2 months ago	61-37529 2 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	60-19256 1 month ago	60-19258 1 month ago	35-30364 35 days
23767	grunweg author:grunweg	refactor: make library notes a definition	Make library notes a definition of `Unit` type, whose doc-string is the note's content. As a consequence, - doc-gen will display all library notes without any custom logic, - library notes are shown upon hover (via the use of the doc-string), - go do definition for library notes is easy Automate this using a macro, which also enforces that all library notes are inside the Mathlib.LibraryNote namespace. Temporarily, we use the `library_note2` name; if/when the batteries version is changed, we can reclaim the original name. This PR does not address how to refer to library notes nicely (in a way that is shown in the documentation, checked for typos, with sufficient imports ensured etc.). That is left to a future PR. This is proposal 2a from this [zulip discussion]([#mathlib4 > library notes @ 💬](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/library.20notes/near/510614740)) ------------ Open questions/TODOs: - should this go in batteries instead? can the old definition just be overwritten? - otherwise, what's the best place for the `LibraryNote` definition? A single file just for this feels overkill; I put it in Mathlib.Tactic.Basic for now. I could use Mathlib.Init, of course (but that might be excessive) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import t-meta merge-conflict	48/48	Archive/Imo/Imo2019Q2.lean,Mathlib/Algebra/BigOperators/Group/Finset/Defs.lean,Mathlib/Algebra/Category/Ring/Limits.lean,Mathlib/Algebra/Group/Action/Defs.lean,Mathlib/Algebra/Group/Conj.lean,Mathlib/Algebra/Group/Defs.lean,Mathlib/Algebra/Group/Hom/Defs.lean,Mathlib/Algebra/Group/Pointwise/Set/Basic.lean,Mathlib/Algebra/Group/Pointwise/Set/Scalar.lean,Mathlib/Algebra/Group/Submonoid/Operations.lean,Mathlib/Algebra/HierarchyDesign.lean,Mathlib/Algebra/Order/Hom/Basic.lean,Mathlib/Analysis/CStarAlgebra/ContinuousFunctionalCalculus/Note.lean,Mathlib/Analysis/RCLike/Lemmas.lean,Mathlib/CategoryTheory/Category/Basic.lean,Mathlib/Data/NNRat/Defs.lean,Mathlib/Data/Nat/Cast/Defs.lean,Mathlib/Data/Nat/Init.lean,Mathlib/Geometry/Manifold/Algebra/Monoid.lean,Mathlib/Geometry/Manifold/ChartedSpace.lean,Mathlib/Logic/Basic.lean,Mathlib/Tactic/Basic.lean,Mathlib/Tactic/NormNum/Basic.lean,Mathlib/Tactic/Simps/Basic.lean,Mathlib/Topology/Algebra/Nonarchimedean/Bases.lean,Mathlib/Topology/Continuous.lean	26	9	['adomani', 'github-actions', 'grunweg', 'leanprover-community-bot-assistant']	nobody	58-32351 1 month ago	58-32353 1 month ago	51-69759 51 days
25138	chrisflav author:chrisflav	chore(RingTheory): remove unnecessary `toRingHom` coercions	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	32/40	Mathlib/RingTheory/Extension/Presentation/Basic.lean,Mathlib/RingTheory/FinitePresentation.lean,Mathlib/RingTheory/Ideal/Cotangent.lean,Mathlib/RingTheory/Ideal/Maps.lean,Mathlib/RingTheory/Ideal/Quotient/Operations.lean,Mathlib/RingTheory/Smooth/Basic.lean,Mathlib/RingTheory/Smooth/Kaehler.lean,Mathlib/RingTheory/Spectrum/Prime/ChevalleyComplexity.lean,Mathlib/RingTheory/Unramified/Basic.lean	9	5	['chrisflav', 'erdOne', 'eric-wieser', 'github-actions', 'leanprover-community-bot-assistant']	nobody	54-20652 1 month ago	54-20654 1 month ago	9-64502 9 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	53-48004 1 month ago	53-48005 1 month ago	64-19141 64 days
24877	smmercuri author:smmercuri	feat: predicates for extensions of complex embeddings	If `L/K`, `ψ : K →+* ℂ`, `φ : L →+* ℂ` we define three predicates asserting ways that `φ` can extend `ψ`. - `IsExtension ψ φ` : the restriction of `φ` to `K` is `ψ`. - `IsMixedExtension ψ φ` : the restriction of `φ` to `K` is `ψ`, `ψ` has real image while `φ` has complex image. - `IsUnmixedExtension ψ φ`: the restriction of `φ` to `K` is `ψ`, `ψ` has real image if and only if `φ` has real image. `IsMixedExtension` and `IsUnmixedExtension` are the `ComplexEmbedding` analogues to ramified and unramified infinite places. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-number-theory merge-conflict	91/0	Mathlib/NumberTheory/NumberField/InfinitePlace/Embeddings.lean	1	7	['github-actions', 'leanprover-community-bot-assistant', 'smmercuri', 'xroblot']	nobody	52-17628 1 month ago	52-17630 1 month ago	21-40253 21 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	49-42083 1 month ago	49-42085 1 month ago	6-40169 6 days
25012	urkud author:urkud	refactor(*): migrate from `Matrix.toLin'` to `Matrix.mulVecLin`	or `Matrix.mulVec` whenever we don't need the `LinearEquiv.symm` part. See [Zulip discussion](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Matrix.2EtoLin'.20vs.20Matrix.2EmulVecLin/with/515188548). It makes sense to have only one normal form, and `Matrix.toLin'` has an extra `DecidableEq` assumption. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict	154/122	Mathlib/Algebra/Lie/Matrix.lean,Mathlib/Algebra/Module/Equiv/Basic.lean,Mathlib/Analysis/CStarAlgebra/Matrix.lean,Mathlib/Analysis/Matrix.lean,Mathlib/Combinatorics/SimpleGraph/LapMatrix.lean,Mathlib/Data/Matrix/Rank.lean,Mathlib/LinearAlgebra/Basis/Defs.lean,Mathlib/LinearAlgebra/Determinant.lean,Mathlib/LinearAlgebra/Finsupp/VectorSpace.lean,Mathlib/LinearAlgebra/FreeModule/Finite/Matrix.lean,Mathlib/LinearAlgebra/Matrix/BilinearForm.lean,Mathlib/LinearAlgebra/Matrix/Charpoly/Minpoly.lean,Mathlib/LinearAlgebra/Matrix/Diagonal.lean,Mathlib/LinearAlgebra/Matrix/Gershgorin.lean,Mathlib/LinearAlgebra/Matrix/SesquilinearForm.lean,Mathlib/LinearAlgebra/Matrix/SpecialLinearGroup.lean,Mathlib/LinearAlgebra/Matrix/ToLin.lean,Mathlib/LinearAlgebra/Matrix/ToLinearEquiv.lean,Mathlib/LinearAlgebra/UnitaryGroup.lean,Mathlib/MeasureTheory/Measure/Lebesgue/Basic.lean,Mathlib/RingTheory/Smooth/StandardSmooth.lean	21	3	['github-actions', 'leanprover-community-bot-assistant']	nobody	48-36917 1 month ago	48-36919 1 month ago	15-74981 15 days
22639	b-reinke author:b-reinke	feat(Mathlib/GroupTheory/FreeGroup): theory of (cyclically) reduced words	Upstreamed from the [EquationalTheories](https://github.com/teorth/equational_theories) project. This PR defines in the new file `Mathlib/GroupTheory/FreeGroup/ReducedWords.lean` some extra lemmas for free groups, in particular about (cyclically) reduced words. ## Main declarations * `FreeGroup.Red.reduced`: the predicate for reduced words * `FreeGroup.Red.cyclicallyReduced`: the predicate for cyclically reduced words ## Main statements * `FreeGroup.infinite_order`: nontrivial elements of a free group have infinite order * `FreeGroup.zpow_left_injective`: taking n-th powers is an injective function on the free group Co-authored-by: Amir Livne Bar-on - [ ] depends on: #23366 - [ ] depends on: #23367 - [x] depends on: #23368 --- [![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$	429/0	Mathlib.lean,Mathlib/GroupTheory/FreeGroup/Basic.lean,Mathlib/GroupTheory/FreeGroup/Reduce.lean,Mathlib/GroupTheory/FreeGroup/ReducedWords.lean	4	3	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	40-25205 1 month ago	40-25208 1 month ago	20-75471 20 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	37-33824 1 month ago	37-33826 1 month 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	37-33822 1 month ago	37-33824 1 month 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	37-33821 1 month ago	37-33822 1 month 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	34-16112 1 month ago	272-42328 8 months ago	129-57991 129 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-algebra merge-conflict label:t-algebra$	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	21-70558 21 days ago	21-70559 21 days ago	172-57747 172 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	21-68087 21 days ago	21-68088 21 days ago	72-51453 72 days
19796	peakpoint author:peakpoint	feat: L'Hopital's rule from within a convex set	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-analysis merge-conflict	190/19	Mathlib/Algebra/Polynomial/Module/Basic.lean,Mathlib/Analysis/Calculus/LHopital.lean,Mathlib/Analysis/Convex/Topology.lean,Mathlib/Geometry/Manifold/Instances/Real.lean,Mathlib/Order/Interval/Set/Basic.lean	5	15	['RemyDegenne', 'github-actions', 'leanprover-community-bot-assistant', 'peakpoint', 'sgouezel']	sgouezel assignee:sgouezel	21-67960 21 days ago	21-67960 21 days ago	80-57750 80 days
23497	chrisflav author:chrisflav	chore(RingTheory/AdicCompletion/AsTensorProduct): golf using five lemma for modules	--- - [x] depends on: #23496 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	30/81	Mathlib/RingTheory/AdicCompletion/AsTensorProduct.lean	1	3	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	21-67573 21 days ago	21-67574 21 days ago	73-63022 73 days
23835	chrisflav author:chrisflav	feat(Topology): cardinality of connected components is bounded by cardinality of fiber	--- - [ ] depends on: #23849 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import t-topology merge-conflict	302/1	Mathlib.lean,Mathlib/Algebra/BigOperators/Finprod.lean,Mathlib/Data/Set/Card/Arithmetic.lean,Mathlib/Data/Set/Finite/Lattice.lean,Mathlib/Data/Set/Lattice.lean,Mathlib/SetTheory/Cardinal/Finite.lean,Mathlib/Topology/Clopen.lean,Mathlib/Topology/Connected/CardComponents.lean,Mathlib/Topology/Connected/Clopen.lean	9	3	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	21-67570 21 days ago	21-67570 21 days ago	1-80438 1 day
24350	erdOne author:erdOne	feat(FieldTheory): fg extension over perfect field is separably generated	Co-authored-by: Christian Merten --- - [x] depends on: #24344 - [x] depends on: #24346 - [x] depends on: #24347 - [x] depends on: #24348 - [x] depends on: #24349 - [x] depends on: #25062 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	466/0	Mathlib.lean,Mathlib/FieldTheory/IntermediateField/Algebraic.lean,Mathlib/FieldTheory/SeparableClosure.lean,Mathlib/FieldTheory/SeparablyGenerated.lean,Mathlib/RingTheory/AlgebraicIndependent/Basic.lean,Mathlib/RingTheory/AlgebraicIndependent/TranscendenceBasis.lean	6	30	['alreadydone', 'erdOne', 'github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	21-67182 21 days ago	21-67183 21 days ago	21-66961 21 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	21-67172 21 days ago	21-67172 21 days 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	21-66926 21 days ago	21-66927 21 days ago	45-4961 45 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 merge-conflict	17/5	Mathlib/Tactic/ComputeDegree.lean,MathlibTest/ComputeDegree.lean	2	3	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	21-66922 21 days ago	21-66923 21 days ago	38-26044 38 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	21-66919 21 days ago	21-66919 21 days ago	11-84822 11 days
25410	JovanGerb author:JovanGerb	chore: remove some duplicate instances	I have a program that finds duplicate instances, as described at [#mathlib4 > duplicate declarations](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/duplicate.20declarations/with/518941841) This PR is a start at fixing these in Mathlib. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict	30/131	Mathlib/Algebra/Category/Grp/Adjunctions.lean,Mathlib/Algebra/Category/ModuleCat/Basic.lean,Mathlib/Algebra/Group/Fin/Basic.lean,Mathlib/Algebra/Homology/Embedding/IsSupported.lean,Mathlib/Algebra/Order/Hom/Monoid.lean,Mathlib/Algebra/Ring/Divisibility/Basic.lean,Mathlib/Algebra/Ring/Subsemiring/Basic.lean,Mathlib/AlgebraicGeometry/Limits.lean,Mathlib/AlgebraicGeometry/OpenImmersion.lean,Mathlib/CategoryTheory/Countable.lean,Mathlib/CategoryTheory/EffectiveEpi/Preserves.lean,Mathlib/CategoryTheory/ObjectProperty/FullSubcategory.lean,Mathlib/Computability/TuringDegree.lean,Mathlib/Data/ENat/Basic.lean,Mathlib/Data/Fintype/EquivFin.lean,Mathlib/Data/List/TakeDrop.lean,Mathlib/Data/Matroid/Constructions.lean,Mathlib/Data/Nat/Basic.lean,Mathlib/Data/Option/Defs.lean,Mathlib/Data/Ordering/Basic.lean,Mathlib/Data/Sign.lean,Mathlib/GroupTheory/Perm/Sign.lean,Mathlib/GroupTheory/Solvable.lean,Mathlib/Logic/Embedding/Basic.lean,Mathlib/Logic/Equiv/Fin/Basic.lean,Mathlib/ModelTheory/Basic.lean,Mathlib/Order/Monotone/Basic.lean,Mathlib/SetTheory/Cardinal/Basic.lean,Mathlib/Tactic/Polyrith.lean,Mathlib/Topology/Compactness/Lindelof.lean	30	10	['JovanGerb', 'adomani', 'eric-wieser', 'github-actions', 'leanprover-community-bot-assistant']	nobody	21-66915 21 days ago	21-66916 21 days ago	31-20030 31 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	3	['VTrelat', 'github-actions', 'leanprover-community-bot-assistant']	nobody	21-66912 21 days ago	21-66913 21 days ago	29-56208 29 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	21-66907 21 days ago	21-66908 21 days ago	26-17604 26 days
25794	dagurtomas author:dagurtomas	feat(CategoryTheory): localization preserves braided structure	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) --- This PR continues the work from #24485. Original PR: https://github.com/leanprover-community/mathlib4/pull/24485	t-category-theory merge-conflict	733/427	Mathlib.lean,Mathlib/CategoryTheory/Localization/Monoidal.lean,Mathlib/CategoryTheory/Localization/Monoidal/Basic.lean,Mathlib/CategoryTheory/Localization/Monoidal/Braided.lean,Mathlib/CategoryTheory/Monoidal/Braided/Basic.lean,Mathlib/CategoryTheory/Sites/Monoidal.lean	6	2	['github-actions', 'leanprover-community-bot-assistant']	nobody	21-66767 21 days ago	21-66767 21 days ago	22-63640 22 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	21-66614 21 days ago	21-66614 21 days ago	18-21880 18 days
26011	linesthatinterlace author:linesthatinterlace	feat: add elementary lifts for `OneHom`, `MulHom`, `MonoidHom` and `RingHom`.	This PR continues the work from #25264. Original PR: https://github.com/leanprover-community/mathlib4/pull/25264	migrated-from-branch t-algebra merge-conflict label:t-algebra$	414/10	Mathlib/Algebra/Group/Hom/Basic.lean,Mathlib/Algebra/Group/Hom/Defs.lean,Mathlib/Algebra/Ring/Hom/Basic.lean,Mathlib/Algebra/Ring/Hom/Defs.lean	4	3	['github-actions', 'leanprover-community-bot-assistant', 'linesthatinterlace']	nobody	21-66610 21 days ago	21-66611 21 days ago	17-68825 17 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	21-66609 21 days ago	21-66610 21 days 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	21-18790 21 days ago	21-18791 21 days 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	20-32043 20 days ago	20-32044 20 days 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	18-47992 18 days ago	18-47992 18 days ago	20-8582 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	31	['Ruben-VandeVelde', 'erdOne', 'faenuccio', 'github-actions', 'leanprover-community-bot-assistant', 'pechersky', 'smmercuri', 'xroblot']	nobody	18-46024 18 days ago	19-30152 19 days ago	79-1228 79 days
23949	Louddy author:Louddy	feat: SkewPolynomial	# Univariate skew polynomials Skew polynomials are represented as `SkewMonoidAlgebra R (Multiplicative ℕ)`, where `R` is usually at least a Semiring. In this file, we define `SkewPolynomial` and provide basic instances. This is currently missing the definition of `coeff` and `single` as they require a more advance interface of `SkewMonoidAlgebra` which is still WIP (See TODOs in file). Co-authored-by: María Inés de Frutos Fernández <[mariaines.dff@gmail.com](mailto:mariaines.dff@gmail.com)> --- - [x] depends on: #22078 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import new-contributor t-algebra merge-conflict label:t-algebra$	600/42	Mathlib.lean,Mathlib/Algebra/SkewMonoidAlgebra/Basic.lean,Mathlib/Algebra/SkewPolynomial/Basic.lean,docs/references.bib	4	3	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	17-36195 17 days ago	17-36197 17 days ago	0-2389 39 minutes
24103	plp127 author:plp127	feat(Topology/UniformSpace/OfCompactT2): generalize theorem	Generalize `uniformSpaceOfCompactT2` to `uniformSpaceOfCompactR1`. --- - [ ] depends on: #24098 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology merge-conflict	48/24	Mathlib/Topology/Separation/Regular.lean,Mathlib/Topology/UniformSpace/OfCompactT2.lean	2	4	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	17-23767 17 days ago	17-23768 17 days ago	76-65641 76 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	15-21294 15 days ago	15-66711 15 days ago	2-8297 2 days
26603	vihdzp author:vihdzp	refactor(SetTheory/Ordinal/FixedPoint): redefine `Ordinal.deriv`	We previously defined the [ordinal derivative](https://en.wikipedia.org/wiki/Normal_function#Properties) of a function as the unique normal function satisfying `deriv f 0 = nfp f 0` and `deriv f (o + 1) = nfp f (deriv f o)` (where `nfp f a` is the next fixed point of `f` that's `≥ a`). The motivation here was to give a "nice" junk value on non-normal functions (the derivative is normal no matter what). However, in practice, this definition makes it unwieldy to prove things, by either requiring a tedious zero/successor/limit argument, or requiring one to rewrite `deriv f = enumOrd (fixedPoints f)`. We can instead define `deriv f = enumOrd (fixedPoints f)`. At the cost of giving "worse" junk values (which we have no legitimate uses of), we're able to much more easily prove all the expected properties in the standard case where `f` is a normal function. Finally, we do some drive-by API cleanup. --- The GitHub diff is a bit messy, I made my best to clean it up. Moved from #21858. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-set-theory merge-conflict	172/197	Mathlib/SetTheory/Cardinal/Regular.lean,Mathlib/SetTheory/Ordinal/FixedPoint.lean,Mathlib/SetTheory/Ordinal/Veblen.lean	3	2	['github-actions', 'leanprover-community-bot-assistant']	nobody	15-12457 15 days ago	15-12457 15 days ago	9-66061 9 days
26895	vihdzp author:vihdzp	feat(SetTheory/Cardinal/Aleph): `IsStrongLimit (preBeth x)`	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-set-theory merge-conflict	20/12	Mathlib/SetTheory/Cardinal/Aleph.lean	1	2	['github-actions', 'kckennylau', 'leanprover-community-bot-assistant']	nobody	15-12332 15 days ago	15-12333 15 days ago	3-18936 3 days
19091	Vierkantor author:Vierkantor	chore(Algebra/MonoidAlgebra): split Defs.lean further	This PR further splits the big file `MonoidAlgebra/Defs.lean` to focus on the ring structure on (`Add`)`MonoidAlgebra`. The following files have been split off: * `MonoidAlgebra/Lift.lean`: definition of `liftNC` * `MonoidAlgebra/MapDomain.lean`: definition of `mapDomain` * `MonoidAlgebra/Module.lean`: module structure (and some submodule results) * `MonoidAlgebra/Opposite.lean`: results on the `MulOpposite` ring structure I also changed one proof about scalar multiplication by natural numbers, so that it wouldn't need a full on module structure on `Finsupp`. This required adding a pair of lemmas on the definition of multiplying `Finsupp`s by natural numbers. --- - [x] depends on: #19087 - [x] depends on: #19205 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra merge-conflict label:t-algebra$	883/560	Mathlib.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/Data/Finsupp/Defs.lean,Mathlib/RingTheory/Polynomial/Opposites.lean	12	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	14-42677 14 days ago	191-36997 6 months ago	2-72196 2 days
26199	Vierkantor author:Vierkantor	fix(Algebra): `MulMemClass.mul_mem` should not be `aesop safe`	The `@[aesop safe apply]` attribute only applies to implications that preserve provability. So for `mul_mem (ha : a ∈ s) (hb : b ∈ s) : a * b ∈ s`, there are ways to prove `a * b ∈ s` while `b ∉ s`, such as when `s` is an ideal and `a ∈ s`. So, instead give `MulMemClass.mul_mem` and `AddMemClass.add_mem` the unsafe attribute, and add `Ideal.mul_mem_left` and `Ideal.mul_mem_right` to the aesop with the same `unsafe` attribute. Now we can prove membership of ideals a bit more easily. Original PR: https://github.com/leanprover-community/mathlib4/pull/24112	t-algebra merge-conflict label:t-algebra$	5/1	Mathlib/Algebra/Group/Subsemigroup/Defs.lean,Mathlib/RingTheory/Ideal/Defs.lean	2	3	['Vierkantor', 'github-actions', 'leanprover-community-bot-assistant']	nobody	11-45430 11 days ago	11-45431 11 days ago	25-3490 25 days
26016	CBirkbeck author:CBirkbeck	Iterated derivatives of tsum's within some open set.	We add some IteratedDerivWithin versions of deriv_tsum using the new SummableLocallyUniformly API. This PR continues the work from #25096. Original PR: https://github.com/leanprover-community/mathlib4/pull/25096	t-analysis merge-conflict	184/0	Mathlib.lean,Mathlib/Algebra/BigOperators/Pi.lean,Mathlib/Analysis/Calculus/Deriv/ZPow.lean,Mathlib/Analysis/Calculus/IteratedDeriv/Defs.lean,Mathlib/Analysis/Calculus/IteratedDeriv/Lemmas.lean,Mathlib/Topology/Algebra/InfiniteSum/TsumUniformlyOn.lean,Mathlib/Topology/Algebra/InfiniteSum/UniformOn.lean	7	3	['CBirkbeck', 'github-actions', 'leanprover-community-bot-assistant']	nobody	8-24103 8 days ago	8-24104 8 days ago	22-40333 22 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/)	infinity-cosmos t-category-theory 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	6-7023 6 days ago	6-7023 6 days ago	88-84229 88 days
27335	eric-wieser author:eric-wieser	chore(Data/List): use simp-normal-form for boolean equalities	This replaces `¬(p x = true)` with `p x = false`. It also makes explicit some adjacent `h : p x` spellings for symmetry, but the `= true`s were already implied by the coercion. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data merge-conflict	43/34	Mathlib/Data/List/DropRight.lean,Mathlib/Data/List/SplitOn.lean,Mathlib/Data/List/TakeWhile.lean	3	2	['github-actions', 'leanprover-community-bot-assistant']	nobody	4-65814 4 days ago	4-65815 4 days ago	0-19242 5 hours
26738	javra author:javra	feat(AlgebraicToplogy/SimplexCategory): add notation for faces and degeneracies general truncated simplex categories	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	infinity-cosmos t-topology t-category-theory merge-conflict	41/29	Mathlib/AlgebraicTopology/SimplexCategory/Truncated.lean,Mathlib/AlgebraicTopology/SimplicialSet/HomotopyCat.lean	2	4	['emilyriehl', 'github-actions', 'leanprover-community-bot-assistant']	nobody	4-52347 4 days ago	4-52347 4 days ago	13-77421 13 days
24064	kim-em author:kim-em	chore: replace `norm_num` with `simp` where applicable	Consider replacing a tactic with a (ahem) simpler alternative. Fairly neutral performance implications, just depends on whether we would like to encourage people to use `simp` where applicable.	maintainer-merge merge-conflict	336/336	Archive/Examples/MersennePrimes.lean,Archive/Imo/Imo1959Q2.lean,Archive/Imo/Imo1960Q1.lean,Archive/Imo/Imo1962Q1.lean,Archive/Imo/Imo1962Q4.lean,Archive/Imo/Imo1981Q3.lean,Archive/Imo/Imo1982Q1.lean,Archive/Imo/Imo2001Q2.lean,Archive/Imo/Imo2005Q4.lean,Archive/Imo/Imo2006Q3.lean,Archive/Imo/Imo2008Q4.lean,Archive/Imo/Imo2024Q1.lean,Archive/Imo/Imo2024Q5.lean,Archive/Imo/Imo2024Q6.lean,Archive/Wiedijk100Theorems/AbelRuffini.lean,Archive/Wiedijk100Theorems/CubingACube.lean,Archive/Wiedijk100Theorems/SumOfPrimeReciprocalsDiverges.lean,Counterexamples/Cyclotomic105.lean,Counterexamples/Phillips.lean,Mathlib/Algebra/Field/NegOnePow.lean,Mathlib/Algebra/Homology/HomotopyCategory/MappingCone.lean,Mathlib/Algebra/Order/CauSeq/BigOperators.lean,Mathlib/Algebra/Polynomial/FieldDivision.lean,Mathlib/Algebra/Polynomial/Roots.lean,Mathlib/Algebra/Polynomial/SpecificDegree.lean,Mathlib/Algebra/Ring/BooleanRing.lean,Mathlib/Algebra/Star/CHSH.lean,Mathlib/AlgebraicGeometry/EllipticCurve/IsomOfJ.lean,Mathlib/AlgebraicTopology/DoldKan/Faces.lean,Mathlib/Analysis/Analytic/Inverse.lean,Mathlib/Analysis/Asymptotics/AsymptoticEquivalent.lean,Mathlib/Analysis/BoxIntegral/UnitPartition.lean,Mathlib/Analysis/CStarAlgebra/ContinuousFunctionalCalculus/Basic.lean,Mathlib/Analysis/CStarAlgebra/ContinuousFunctionalCalculus/Order.lean,Mathlib/Analysis/CStarAlgebra/Module/Defs.lean,Mathlib/Analysis/Calculus/FDeriv/Measurable.lean,Mathlib/Analysis/Calculus/FDeriv/Norm.lean,Mathlib/Analysis/Calculus/FDeriv/Symmetric.lean,Mathlib/Analysis/Complex/AbelLimit.lean,Mathlib/Analysis/Convex/Between.lean,Mathlib/Analysis/Convex/Function.lean,Mathlib/Analysis/Convolution.lean,Mathlib/Analysis/Fourier/AddCircle.lean,Mathlib/Analysis/Fourier/AddCircleMulti.lean,Mathlib/Analysis/Fourier/Inversion.lean,Mathlib/Analysis/Fourier/RiemannLebesgueLemma.lean,Mathlib/Analysis/InnerProductSpace/NormPow.lean,Mathlib/Analysis/InnerProductSpace/Projection.lean,Mathlib/Analysis/InnerProductSpace/l2Space.lean,Mathlib/Analysis/MeanInequalities.lean,Mathlib/Analysis/MellinInversion.lean,Mathlib/Analysis/Normed/Affine/Simplex.lean,Mathlib/Analysis/Normed/Algebra/TrivSqZeroExt.lean,Mathlib/Analysis/Normed/Group/ControlledClosure.lean,Mathlib/Analysis/Normed/Lp/lpSpace.lean,Mathlib/Analysis/Normed/Operator/Banach.lean,Mathlib/Analysis/Normed/Ring/Units.lean,Mathlib/Analysis/NormedSpace/HahnBanach/Separation.lean,Mathlib/Analysis/NormedSpace/MStructure.lean,Mathlib/Analysis/NormedSpace/RieszLemma.lean,Mathlib/Analysis/Oscillation.lean,Mathlib/Analysis/SpecialFunctions/BinaryEntropy.lean,Mathlib/Analysis/SpecialFunctions/Complex/Log.lean,Mathlib/Analysis/SpecialFunctions/ContinuousFunctionalCalculus/Rpow/Basic.lean,Mathlib/Analysis/SpecialFunctions/ContinuousFunctionalCalculus/Rpow/Isometric.lean,Mathlib/Analysis/SpecialFunctions/ExpDeriv.lean,Mathlib/Analysis/SpecialFunctions/Gamma/Beta.lean,Mathlib/Analysis/SpecialFunctions/Gamma/BohrMollerup.lean,Mathlib/Analysis/SpecialFunctions/Gamma/Deligne.lean,Mathlib/Analysis/SpecialFunctions/Gaussian/GaussianIntegral.lean,Mathlib/Analysis/SpecialFunctions/Integrals/Basic.lean,Mathlib/Analysis/SpecialFunctions/Log/Monotone.lean,Mathlib/Analysis/SpecialFunctions/Pow/Real.lean,Mathlib/Analysis/SpecialFunctions/Trigonometric/Angle.lean,Mathlib/Analysis/SpecialFunctions/Trigonometric/Basic.lean,Mathlib/Analysis/SpecialFunctions/Trigonometric/Complex.lean,Mathlib/Analysis/SpecialFunctions/Trigonometric/Inverse.lean,Mathlib/Combinatorics/Additive/AP/Three/Behrend.lean,Mathlib/Combinatorics/Additive/SmallTripling.lean,Mathlib/Combinatorics/Extremal/RuzsaSzemeredi.lean,Mathlib/Combinatorics/SimpleGraph/Density.lean,Mathlib/Combinatorics/SimpleGraph/Regularity/Bound.lean,Mathlib/Combinatorics/SimpleGraph/Regularity/Chunk.lean,Mathlib/Combinatorics/SimpleGraph/Regularity/Increment.lean,Mathlib/Combinatorics/SimpleGraph/Regularity/Lemma.lean,Mathlib/Combinatorics/SimpleGraph/Triangle/Basic.lean,Mathlib/Combinatorics/SimpleGraph/Triangle/Counting.lean,Mathlib/Computability/Ackermann.lean,Mathlib/Computability/DFA.lean,Mathlib/Data/Complex/Basic.lean,Mathlib/Data/Complex/Trigonometric.lean,Mathlib/Data/Nat/Bits.lean,Mathlib/Data/Nat/Choose/Central.lean,Mathlib/Data/Nat/Choose/Sum.lean,Mathlib/Data/Nat/Digits/Defs.lean,Mathlib/Data/Nat/Prime/Defs.lean,Mathlib/Data/Real/GoldenRatio.lean,Mathlib/Data/Real/Pi/Bounds.lean,Mathlib/Data/Real/Pi/Irrational.lean,Mathlib/Data/Real/Sign.lean	170	19	['Ruben-VandeVelde', 'YaelDillies', 'adomani', 'euprunin', 'github-actions', 'leanprover-bot', 'leanprover-community-bot-assistant', 'leanprover-community-mathlib4-bot']	nobody	3-24690 3 days ago	3-24691 3 days ago	31-30192 31 days
27260	JovanGerb author:JovanGerb	feat(Geometry/Euclidean/SignedDist): `signedDist` between two points	original PR: #24245 This PR defines `signedDist`, the signed distance between two points. TODO: It redefines `signedInfDist` so that it uses `signedDist`. The motivation is to use this in IMO2020Q6. Additionally this definition will be useful for properly reasoning about the power of a point [#mathlib4 > Signed distance between points](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Signed.20distance.20between.20points) some comments: * should `signedDistLinear` be `private`? * I'm not too happy about the hypothesis in `signedDist_congr (h : ∃ r > (0 : ℝ), r • v = w)`. This relationship between `v` and `w` is a symmetric one that should have some API around it, similar to `SameRay`. It could also be spelled as `(ℝ≥0 ∙ v) = ℝ≥0 ∙ w` --- - [x] depends on: #27259 - [ ] depends on : #27285 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	merge-conflict	207/30	Mathlib/Analysis/InnerProductSpace/Basic.lean,Mathlib/Analysis/Normed/Lp/ProdLp.lean,Mathlib/Geometry/Euclidean/SignedDist.lean,Mathlib/Topology/MetricSpace/Pseudo/Defs.lean	4	4	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	2-84135 2 days ago	2-84136 2 days ago	4-56688 4 days
26644	kckennylau author:kckennylau	feat(SetTheory/ZFC): Define the language of sets and state the ZFC axioms	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-set-theory merge-conflict	381/0	Mathlib.lean,Mathlib/SetTheory/ZFC/Axioms.lean,docs/references.bib	3	46	['github-actions', 'kckennylau', 'leanprover-community-bot-assistant', 'staroperator', 'vihdzp']	nobody	2-55072 2 days ago	2-55073 2 days ago	21-29357 21 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	1-11267 1 day ago	1-11268 1 day ago	23-63406 23 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	355-27653 11 months ago	360-21318 11 months 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	345-45029 11 months ago	345-45029 11 months ago	6-38745 6 days
11207	luigi-massacci author:luigi-massacci	feat(Topology/MetricSpace): Add new file with type of Katetov maps	add a type of Katetov maps (one point extensions of a metric) and related notation and FunLike coercions. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-topology WIP	138/0	Mathlib.lean,Mathlib/Topology/MetricSpace/Katetov.lean,docs/references.bib	3	16	['fpvandoorn', 'jcommelin', 'kim-em', 'luigi-massacci', 'urkud']	nobody	341-29406 11 months ago	443-31491 1 year ago	26-83567 26 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	341-29281 11 months ago	345-42207 11 months 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	328-4773 10 months ago	359-50432 11 months ago	7-3203 7 days
16773	arulandu author:arulandu	feat(Probability/Distributions): formalize Beta distribution	Formalize Beta distribution, using Gamma distribution as a reference. Added real-valued beta wrapper, in the manner of gamma. Thanks to @EtienneC30 for help with casting real <-> complex. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-measure-probability awaiting-author	286/1	Mathlib.lean,Mathlib/Analysis/SpecialFunctions/Gamma/Beta.lean,Mathlib/Probability/Distributions/Beta.lean	3	48	['EtienneC30', 'arulandu', 'github-actions', 'vihdzp']	arulandu assignee:arulandu	309-51390 10 months ago	314-48108 10 months ago	1-21124 1 day
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	20	['Vierkantor', 'YaelDillies', 'github-actions', 'js2357', 'kbuzzard', 'leanprover-community-mathlib4-bot']	Vierkantor assignee:Vierkantor	305-30234 10 months ago	305-30352 10 months ago	26-39463 26 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	277-23775 9 months ago	277-23775 9 months 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	187-48310 6 months ago	187-48310 6 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	187-35075 6 months ago	188-36028 6 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	157-838 5 months ago	161-68834 5 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	156-86317 5 months ago	156-86317 5 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	151-1113 5 months ago	151-2240 5 months ago	0-1528 25 minutes
22390	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)`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-category-theory awaiting-author	112/1	Mathlib/CategoryTheory/Category/Factorisation.lean	1	9	['YunkaiZhang233', 'github-actions', 'joelriou']	nobody	145-41746 4 months ago	148-37218 4 months ago	0-6513 1 hour
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	131-48660 4 months ago	131-48660 4 months ago	20-81771 20 days
18091	tukamilano author:tukamilano	feat: Hoeffding's lemma	Formalize Hoeffding's lemma using the property of cumulant. Co-authored-by: Yuma Mizuno [mizuno.y.aj@gmail.com](mailto:mizuno.y.aj@gmail.com) --- - [x] depends on: #20151	large-import new-contributor t-measure-probability awaiting-author	339/0	Mathlib.lean,Mathlib/Probability/Hoeffding.lean,Mathlib/Probability/Moments/Basic.lean,Mathlib/Probability/Moments/MGFAnalytic.lean,docs/references.bib	5	55	['RemyDegenne', 'YaelDillies', 'github-actions', 'mathlib4-dependent-issues-bot', 'tukamilano', 'yuma-mizuno']	tukamilano assignee:tukamilano	128-40276 4 months ago	128-40284 4 months ago	1-58489 1 day
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 awaiting-author	29/0	Mathlib/Analysis/Asymptotics/SpecificAsymptotics.lean	1	2	['b-mehta', 'github-actions']	b-mehta assignee:b-mehta	110-31176 3 months ago	120-25653 3 months ago	9-59130 9 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	109-63986 3 months ago	109-63986 3 months ago	51-9403 51 days
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	86/0	Mathlib/Combinatorics/SimpleGraph/Acyclic.lean	1	6	['Rida-Hamadani', 'b-mehta', 'github-actions', 'grunweg']	b-mehta assignee:b-mehta	109-29643 3 months ago	109-29664 3 months ago	131-20338 131 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/)	new-contributor t-analysis awaiting-author WIP help-wanted	411/0	Mathlib/PlaceHolder/ToeplitzHausdorff.lean,Mathlib/PlaceHolder/ToeplitzHausdorff_v2.lean	2	10	['faenuccio', 'ggranberry', 'github-actions']	faenuccio assignee:faenuccio	100-7473 3 months ago	100-7473 3 months ago	4-24257 4 days
22349	dtumad author:dtumad	feat(Control): Laws for monads with compatible `failure` operation	Add a class for a `Monad` that also has an `Alternative` instance, and a class `LawfulAlternative` for types where the failure and monad structures are compatible in the expected way. --- I'm not sure if this should instead go in `Batteries.Control` instead of mathlib, or at least lemmas like `OptionT.run_failure` maybe should. Some of the instances like `Set` would still need to be added in mathlib either way. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-meta WIP	74/3	Mathlib.lean,Mathlib/Control/Lawful.lean,Mathlib/Control/Monad/AlternativeMonad.lean	3	8	['dtumad', 'eric-wieser', 'github-actions', 'quangvdao']	nobody	91-65167 3 months ago	91-65321 3 months ago	1-20563 1 day
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	84-55057 2 months ago	84-55057 2 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	82-1376 2 months ago	82-1385 2 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	82-687 2 months ago	82-1322 2 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	78-46051 2 months ago	78-46051 2 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	76-46915 2 months ago	76-46915 2 months ago	27-52316 27 days
22948	pelicanhere author:pelicanhere	feat(Algebra/DirectSum): morphism of directsum decomposition	Define morphism of directsum decomposition, which would be later used in defineing graded ring hom. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra label:t-algebra$	83/0	Mathlib/Algebra/DirectSum/Decomposition.lean	1	9	['eric-wieser', 'github-actions', 'pelicanhere']	eric-wieser assignee:eric-wieser	75-50970 2 months ago	133-47788 4 months ago	133-47827 133 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	70-17061 2 months ago	70-17079 2 months ago	0-0 0 seconds
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	187/0	Mathlib.lean,Mathlib/Combinatorics/SimpleGraph/Cycle.lean	2	29	['IvanRenison', 'github-actions']	kmill assignee:kmill	65-78143 2 months ago	93-75700 3 months ago	93-75751 93 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 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	54	['Paul-Lez', 'YaelDillies', 'github-actions', 'joneugster', 'kbuzzard', 'miguelmarco']	Paul-Lez assignee:Paul-Lez	61-34057 2 months ago	73-14810 2 months ago	22-16933 22 days
25225	xcloudyunx author:xcloudyunx	feat(Combinatorics/SimpleGraph): Eulerian walk in connected graph contains all vertices	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-combinatorics	16/0	Mathlib/Combinatorics/SimpleGraph/Trails.lean	1	3	['IvanRenison', 'github-actions']	nobody	60-6573 1 month ago	60-84385 1 month ago	60-84439 60 days
24804	Moises-Herradon-Cueto author:Moises-Herradon-Cueto	feat(CategoryTheory/Limits/Preserves/Shapes): show that if a functor preserves limits, so does `Over.post`	If a functor `F` preserves limits (of a certain shape, finite, or of a certain size), then so does the induced functor on `Over` categories. From Toric Co-authored-by: Yaël Dillies --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	toric new-contributor t-category-theory	125/0	Mathlib.lean,Mathlib/CategoryTheory/Limits/Preserves/Shapes/Over.lean,Mathlib/CategoryTheory/WithTerminal/Basic.lean	3	17	['Moises-Herradon-Cueto', 'YaelDillies', 'erdOne', 'github-actions', 'joelriou']	nobody	59-52841 1 month ago	60-28783 1 month ago	66-33177 66 days
20238	maemre author:maemre	feat(Computability/DFA): Closure of regular languages under some set operations	This shows that regular languages are closed under complement and intersection by constructing DFAs for them. --- Closure under all other operations will be proved when someone adds the proof for DFA<->regular expression equivalence, so they are not part of this PR. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-zulip t-computability new-contributor awaiting-author	159/0	Mathlib/Computability/DFA.lean,Mathlib/Computability/Language.lean	2	59	['EtienneC30', 'YaelDillies', 'github-actions', 'maemre', 'meithecatte', 'urkud']	EtienneC30 assignee:EtienneC30	52-53547 1 month ago	82-1286 2 months ago	48-67492 48 days
18693	Ruben-VandeVelde author:Ruben-VandeVelde	feat: add ConjRootClass	Co-authored-by: FR --- From #6718 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra delegated label:t-algebra$	213/0	Mathlib.lean,Mathlib/FieldTheory/Minpoly/ConjRootClass.lean,Mathlib/FieldTheory/Minpoly/IsConjRoot.lean	3	16	['LessnessRandomness', 'Vierkantor', 'alreadydone', 'github-actions', 'grunweg', 'mathlib-bors']	Vierkantor assignee:Vierkantor	50-53383 1 month ago	61-28936 2 months ago	94-8480 94 days
23992	robertmaxton42 author:robertmaxton42	feat (Limits.FunctorCategory): limitIsoFlipCompLim and colimitIsoFlipCompColim are natural	Add `limIsoFlipCompWhiskerLim`, `limCompFlipIsoWhiskerLim`, `colimIsoFlipCompWhiskerColim`, `colimCompFlipIsoWhiskerColim`, each witnessing that their corresponding families of isomorphisms are 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 awaiting-CI	41/0	Mathlib/CategoryTheory/Limits/FunctorCategory/Basic.lean	1	12	['adomani', 'github-actions', 'robertmaxton42', 'robin-carlier']	nobody	50-44524 1 month ago	50-85879 1 month ago	50-83251 50 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	50-35324 1 month ago	50-35324 1 month 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	49-10938 1 month ago	49-10939 1 month 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	45-81843 1 month ago	107-37139 3 months ago	30-77130 30 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	16/0	Mathlib/MeasureTheory/Integral/Bochner/Set.lean	1	1	['github-actions']	nobody	44-34819 1 month ago	44-34819 1 month ago	0-11893 3 hours
25858	themathqueen author:themathqueen	feat(RingTheory/Coalgebra/MulOpposite): coalgebra instance for MulOpposite	Adding an instance for `Aᵐᵒᵖ` being an `R`-coalgebra when `A` is. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra label:t-algebra$	112/0	Mathlib.lean,Mathlib/RingTheory/Coalgebra/MulOpposite.lean	2	1	['github-actions']	nobody	38-3474 1 month ago	42-35273 1 month ago	42-35318 42 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	354/0	Mathlib.lean,Mathlib/MeasureTheory/VectorMeasure/Variation/Defs.lean	2	1	['github-actions']	nobody	36-52854 1 month ago	37-33871 1 month ago	37-33920 37 days
24395	rudynicolop author:rudynicolop	feat(Data/List): list splitting definitions and lemmas	Adds definitions and lemmas for obtaining all prefixes and suffixes of lists. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data new-contributor awaiting-author	143/2	Mathlib/Data/List/Perm/Lattice.lean,Mathlib/Data/List/TakeDrop.lean	2	4	['BoltonBailey', 'github-actions']	ericrbg assignee:ericrbg	34-3283 1 month ago	34-3283 1 month ago	57-9536 57 days
26301	Ivan-Sergeyev author:Ivan-Sergeyev	feat(LinearAlgebra/Matrix/Determinant/TotallyUnimodular):	Empty matrices are totally unimodular. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra label:t-algebra$	15/0	Mathlib/LinearAlgebra/Matrix/Determinant/TotallyUnimodular.lean	1	1	['github-actions']	nobody	33-33154 1 month ago	33-33164 1 month ago	33-33208 33 days
26376	maddycrim author:maddycrim	Simons2025	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import new-contributor WIP	29/0	Mathlib/RingTheory/Localization/Pi.lean	1	1	['github-actions']	faenuccio assignee:faenuccio	31-29273 1 month ago	32-7746 1 month ago	0-13 13 seconds
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	321/11	Mathlib.lean,Mathlib/Analysis/InnerProductSpace/Basic.lean,Mathlib/Analysis/NormedSpace/Normalized.lean,Mathlib/Geometry/Euclidean/Angle/Unoriented/Affine.lean,Mathlib/Geometry/Euclidean/Angle/Unoriented/Basic.lean,Mathlib/Geometry/Euclidean/Angle/Unoriented/TriangleInequality.lean,Mathlib/Geometry/Euclidean/Angle/Unoriented/UnitVectorAngles.lean	7	21	['LessnessRandomness', 'Timeroot', 'github-actions', 'jsm28']	nobody	30-83674 1 month ago	33-48293 1 month ago	35-33723 35 days
26453	jburroni author:jburroni	feat(Data/PNat/Basic): add order-related instances to PNat	Add `SuccAddOrder ℕ+` and `NoMaxOrder ℕ+` instances. This allows, for example, the use of lemmas related to `Intervals` built with ℕ+. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import t-data new-contributor	18/0	Mathlib/Data/PNat/Basic.lean	1	3	['eric-wieser', 'github-actions', 'jburroni']	nobody	29-31303 29 days ago	30-15161 1 month ago	30-15206 30 days
26023	Garmelon author:Garmelon	chore: add githelper.py script	As described in the readme file, this somewhat opinionated script aims to help fix weird git repo setups and restore them to a standardized state that closely matches what `gh repo clone` does. Like `migrate_to_fork.py`, this script requires the user to have `git` and `gh` installed. To use the script, run `scripts/githelper.py fix` in a git repo that is either a clone of mathlib or of a mathlib fork. The script will prompt you before making any changes, so the user retains control over the entire process. The script also prints the commands used. `fix` is a subcommand so other git and github management tasks can be added in the future. Possible examples: Deleting branches of closed PRs, keeping the fork in sync with upstream, removing branches from a fork that was accidentally cloned with all mathlib branches included. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor	490/0	scripts/README.md,scripts/githelper.py	2	8	['Garmelon', 'bryangingechen', 'github-actions', 'jcommelin']	bryangingechen assignee:bryangingechen	28-78346 28 days ago	28-78346 28 days ago	31-1222 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). I am not sure whether the `prodEquivOfIsCompl_symm_apply` theorem should be tagged with `@[simp]`; this might lead to confluence issues. Opinions are welcome! Co-authored by: - [Viviana del Barco](https://github.com/vdelbarc) - [Gustavo Infanti](https://github.com/GuQOliveira) - [Exequiel Rivas](https://github.com/erivas) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra label:t-algebra$	9/0	Mathlib/LinearAlgebra/Projection.lean	1	5	['PSchwahn', 'github-actions', 'kckennylau']	nobody	27-84913 27 days ago	29-70547 29 days ago	29-70672 29 days
25739	literandltx author:literandltx	feat(NumberTheory/LegendreSymbol): Add sqrt‐of‐residue theorems for p=4k+3 and p=8k+5	Add a new file `QuadraticResidueRoots.lean` under `Mathlib/NumberTheory/LegendreSymbol/` that proves two explicit “square-root of quadratic residue” theorems for primes of the specific form. - `exists_sqrt_of_residue_mod4_eq3` for primes `p = 4k + 3` - `exists_sqrt_of_residue_mod8_eq5`* for primes `p = 8*k + 5` It also introduces the helper lemmas `euler_criterion_traditional` and `legendreSym.at_two_mod8_eq_5`. Import lines in `Mathlib.lean` and `Mathlib/NumberTheory/LegendreSymbol/Basic.lean` have been updated accordingly.	new-contributor t-number-theory 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	26-48800 26 days ago	26-77886 26 days 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	25-37175 25 days ago	25-49467 25 days ago	13-85893 13 days
26638	metakunt author:metakunt	chore: Add grind to cast_zero	Add grind to cast_zero	t-data new-contributor	1/1	Mathlib/Data/Nat/Cast/Defs.lean	1	1	['github-actions']	nobody	24-12803 24 days ago	24-12803 24 days ago	24-14406 24 days
23986	ShouxinZhang author:ShouxinZhang	feat(FieldTheory/RatFunc): add RatFunc.toFractionRingAlgEquiv	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra label:t-algebra$	13/0	Mathlib/FieldTheory/RatFunc/Basic.lean	1	32	['ShouxinZhang', 'eric-wieser', 'github-actions', 'joneugster', 'kckennylau', 'plp127']	nobody	23-79911 23 days ago	26-6367 26 days ago	104-69305 104 days
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 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	4	['YaelDillies', 'erdOne', 'github-actions', 'mathlib4-dependent-issues-bot']	nobody	23-23125 23 days ago	23-23125 23 days ago	43-26015 43 days
26710	metakunt author:metakunt	feat (Data/Nat/Digits/Lemmas): Add digits_getD	Adds digits_getD, an explicit computation of the i-th digits of n in base b representation.	t-data new-contributor	64/0	Mathlib/Data/Nat/Digits/Lemmas.lean	1	1	['github-actions']	nobody	22-81858 22 days ago	22-81989 22 days ago	22-82041 22 days
26597	sahanwijetunga author:sahanwijetunga	Update Orthogonal.lean	fixed documentation for orthogonal (regarding order of inputs to bilinear form) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra documentation label:t-algebra$	3/3	Mathlib/LinearAlgebra/BilinearForm/Orthogonal.lean	1	2	['github-actions', 'mbkybky']	nobody	22-58012 22 days ago	22-58019 22 days ago	25-10486 25 days
26227	Rob23oba author:Rob23oba	chore: adaptation for leanprover/lean4#8884	There seems to be some weird bug in aesop or something that aesop uses where the environment isn't properly reconstructed (e.g. not in `simp` since the output of `aesop?` works). I'm not going to try to figure this out here though. (also it seems like this is an issue that should've also occurred before leanprover/lean4#8884. I can not really explain how this hasn't surfaced yet)	new-contributor	7/0	Mathlib/SetTheory/Ordinal/Veblen.lean	1	0	[]	nobody	21-64608 21 days ago	21-64609 21 days ago	21-64642 21 days
22503	Kevew author:Kevew	chore: deduce `Nat.multiplicity` lemmas from the `Nat.factorization` ones	Ported lemmas from `Data/Nat/Multiplicity` to into a new file called `Data/Nat/Factorization/Multiplicity`, re-written in terms of `factorization`. --- - [x] depends on: #24576 - [ ] depends on: #25002 - [ ] depends on: #26142 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import t-data new-contributor blocked-by-other-PR	338/120	Mathlib.lean,Mathlib/Algebra/Order/Antidiag/Nat.lean,Mathlib/Data/Nat/Factorization/Basic.lean,Mathlib/Data/Nat/Factorization/Defs.lean,Mathlib/Data/Nat/Factorization/LCM.lean,Mathlib/Data/Nat/Factorization/Multiplicity.lean,Mathlib/Data/Nat/Multiplicity.lean,Mathlib/GroupTheory/Exponent.lean,Mathlib/NumberTheory/Cyclotomic/PrimitiveRoots.lean,Mathlib/RingTheory/RootsOfUnity/PrimitiveRoots.lean	10	41	['Kevew', 'Paul-Lez', 'YaelDillies', 'github-actions', 'grunweg', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	21-53691 21 days ago	21-59909 21 days ago	63-40264 63 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	21-48533 21 days ago	21-49062 21 days ago	15-65390 15 days
26165	oliver-butterley author:oliver-butterley	feat(MeasureTheory.VectorMeasure): add lemma which shows that variation of a `ℝ≥0∞` VectorMeasure is equal to itself	Add a lemma for the variation of a VectorMeasure which tells that if `μ` is `VectorMeasure X ℝ≥0∞` then `variation μ = μ`. Co-authored-by: @yoh-tanimoto - [ ] depends on: #26160 --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-measure-probability 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	21-48533 21 days ago	21-49089 21 days ago	15-66224 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	21-48532 21 days ago	21-49141 21 days ago	15-68781 15 days
26785	TOMILO87 author:TOMILO87	feat: beta distribution	Add the Beta distribution to the probability distributions in mathlib4. This implementation includes: - Definition of the Beta function over the reals - The probability density function (PDF) of the Beta distribution - Proof that the PDF integrates to 1 - The corresponding `Measure` and CDF - Lemmas about measurability, positivity, and integrability The Beta distribution is a family of continuous probability distributions defined on the interval [0, 1], parametrized by two positive shape parameters, `α` and `β`, that control the shape of the distribution. This follows the general structure of other distributions in mathlib, such as the Gamma distribution. --- This is a clean version of the PR originally opened as [#25608](https://github.com/leanprover-community/mathlib4/pull/25608) and temporarily migrated in [#26325](https://github.com/leanprover-community/mathlib4/pull/26325). It includes: - `456da1c`: Initial version of the distribution - `c047aee`: Address review comments from @EtienneC30 - `f165c79`: Remove `ae` condition from `lintegral_betaPDF_eq` - `7875f47`: Lint fix for unused simp args This PR is rebased onto `master` and follows the fork-based workflow. Thanks for your helpful comments earlier!	new-contributor t-measure-probability	285/0	Mathlib.lean,Mathlib/Analysis/SpecialFunctions/Gamma/Beta.lean,Mathlib/Probability/Distributions/Beta.lean	3	1	['github-actions']	nobody	19-54390 19 days ago	19-54390 19 days ago	21-31247 21 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 easy	13/0	Mathlib/MeasureTheory/PiSystem.lean	1	10	['KiringYJ', 'github-actions', 'ocfnash']	nobody	19-32388 19 days ago	19-55641 19 days ago	22-16097 22 days
26790	FlAmmmmING author:FlAmmmmING	feat(Combinatorics/Enumerative/Bell.lean): define standard Bell number	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-combinatorics	38/1	Mathlib/Combinatorics/Enumerative/Bell.lean	1	11	['AntoineChambert-Loir', 'FlAmmmmING', 'eric-wieser', 'github-actions', 'kckennylau', 'madvorak']	nobody	19-27355 19 days ago	21-24017 21 days ago	21-24064 21 days
26909	gasparattila author:gasparattila	feat(LinearAlgebra/Projectivization/Subspace): correspondence between linear and projective subspaces	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra label:t-algebra$	51/3	Mathlib/LinearAlgebra/Projectivization/Subspace.lean	1	1	['github-actions']	nobody	18-9810 18 days ago	18-9816 18 days ago	18-9865 18 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	365/0	Mathlib.lean,Mathlib/Analysis/Calculus/FDeriv/Partial.lean,Mathlib/Analysis/Normed/Operator/BoundedLinearMaps.lean	3	7	['YaelDillies', 'agjftucker', 'github-actions', 'igorkhavkine', 'mathlib4-dependent-issues-bot']	nobody	18-1016 18 days ago	30-53024 1 month ago	31-38762 31 days
26814	KiringYJ author:KiringYJ	feat(MeasureTheory): expose `m.SigmaAlgebra` and `IsSigmaAlgebra`	(New PR opened because I mis-clicked “Merge” on the previous branch and had to revert it.) This PR introduces a lightweight API for treating the σ‑algebra of a `MeasurableSpace` as a plain `Set (Set α)`, plus a semantic predicate `IsSigmaAlgebra` and small bridges between bundled and un‑bundled views. #### Motivation The immediate goal is to prepare for a formalization of the monotone class theorem. With `m.SigmaAlgebra` and the `IsSigmaAlgebra` predicate, one can state the theorem as a clean equality of families of sets, e.g. ```lean SigmaAlgebra.generateFrom G = MonotoneClass.generateFrom G ``` rather than the more cumbersome phrasing "`s` is measurable ↔ `s` belongs to the smallest monotone class containing `G`". The helpers in this PR make those equalities ergonomic and reusable. #### What’s new - `m.SigmaAlgebra` – the collection of all `m`‑measurable sets, exposed as a value of type `Set (Set α)`. Lets you write `s ∈ m.SigmaAlgebra` instead of `MeasurableSet[m] s`. - `IsSigmaAlgebra F` – predicate saying that a family of sets `A` is already a σ‑algebra, defined by `(generateFrom F).SigmaAlgebra = F`. - `generateFrom_sigmaAlgebra_eq` – idempotence lemma `generateFrom m.SigmaAlgebra = m` (`@[simp]`). - Boolean‑algebra instance on `m.SigmaAlgebra` (alias of the existing subtype instance). - Helper lemmas: - `Subtype.mem_sigma` – bundled measurable set ∈ `m.SigmaAlgebra`. - `Set.toMeasurableSubtype` – wrap a membership proof into the subtype. #### House‑keeping - Removed two obsolete `noncomputable` keywords from `Mathlib/MeasureTheory/MeasurablyGenerated.lean`; the affected instances are now computable. #### Notes - No breaking changes: the new definitions are additive; existing code continues to compile unchanged. - No dependencies on other PRs: this patch is self‑contained.	new-contributor t-measure-probability	86/3	Mathlib.lean,Mathlib/MeasureTheory/MeasurableSpace/MeasurablyGenerated.lean,Mathlib/MeasureTheory/MeasurableSpace/SigmaAlgebra.lean	3	1	['github-actions']	nobody	16-61059 16 days ago	20-50028 20 days ago	20-50074 20 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	50/2	Mathlib/Analysis/Calculus/Deriv/Star.lean	1	7	['emo916math', 'github-actions', 'kckennylau']	nobody	16-12940 16 days ago	19-9978 19 days ago	19-10023 19 days
26945	gasparattila author:gasparattila	feat(LinearAlgebra/AffineSpace/AffineSubspace): basic properties of `sInf` and `iInf`	These properties are analogous to the existing ones for the binary infimum. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra label:t-algebra$	48/1	Mathlib/LinearAlgebra/AffineSpace/AffineSubspace/Defs.lean	1	4	['Ruben-VandeVelde', 'gasparattila', 'github-actions']	nobody	15-50760 15 days ago	17-15776 17 days ago	17-15823 17 days
26986	WangYiran01 author:WangYiran01	feat(Partition): add bijection for partitions with max part ≤ r	## Summary This PR adds a new theorem `partition_max_equals_bound` to `Mathlib.Combinatorics.Enumerative.Partition`. It constructs a bijection between: - The set of partitions of `n` in which `r ∈ π.parts` and all parts are `≤ r`, and - The set of partitions of `n - r` whose largest part is at most `r`. This provides a constructive proof via removing/adding `r` from/to the partition multiset, in line with classical enumerative combinatorics. ## Implementation notes - The proof uses `Multiset.erase` and `Multiset.cons` with basic properties of `sum`, `sup`, and `Partition` structures. - The bijection is implemented explicitly via `f` and `g`, and proven mutually inverse via `Subtype.ext`. ## Linting - [x] Passes `lake build` - [x] Linter clean (no commandStart or longLine issues) ## Author Contributed by Yiran Wang.	new-contributor t-combinatorics	85/0	Mathlib/Combinatorics/Enumerative/Partition.lean	1	2	['WangYiran01', 'github-actions']	nobody	15-47212 15 days ago	15-48577 15 days ago	15-48622 15 days
27000	gasparattila author:gasparattila	feat(Analysis/Normed/Group/Quotient): isometric versions of isomorphisms	This PR adds an isometric version of the third isomorphism theorem for groups and modules. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import new-contributor t-analysis	49/2	Mathlib/Analysis/Normed/Group/Quotient.lean	1	1	['github-actions']	nobody	15-31340 15 days ago	15-31342 15 days ago	15-31395 15 days
26272	ajirving author:ajirving	feat(NumberTheory/LucasLehmer): prove converse direction to Lucas-Lehmer	Proves the converse direction of the Lucas-Lehmer test, namely that the Lucas-Lehmer criterion is a necessary condition for a Mersenne prime. Adds a couple of examples of proving Mersenne numbers are composite using this. Proves that if `2^p-1` is prime then `p` is prime. --- * I wasn't sure how many examples to add given that there are many more Mersenne composites than primes. * There are a number of annoying coercions between different rings, any simplifications will be appreciated. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import new-contributor t-number-theory	226/5	Archive/Examples/MersennePrimes.lean,Mathlib/NumberTheory/LucasLehmer.lean	2	12	['github-actions', 'kckennylau']	nobody	14-57175 14 days ago	34-26596 1 month ago	34-26642 34 days
24527	matthewjasper author:matthewjasper	feat(Topology/Algebra/Module): Add more theorems for IsModuleTopology	Add theorems that surjective linear maps to the module topology are open. Add IsModuleTopology instance for quotients. Add IsModuleTopology instance for finite dimensional T2 vector spaces over a complete normed field and use it to shorten some proofs. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra t-topology label:t-algebra$	48/24	Mathlib/Topology/Algebra/Module/FiniteDimension.lean,Mathlib/Topology/Algebra/Module/ModuleTopology.lean	2	7	['erdOne', 'github-actions', 'matthewjasper', 'riccardobrasca']	nobody	13-37647 13 days ago	84-40262 2 months ago	86-8559 86 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	13-9225 13 days ago	13-21709 13 days ago	0-13398 3 hours
25910	themathqueen author:themathqueen	feat(Algebra/Ring/Idempotent): subtraction lemmas for idempotents and star projections	This allows us to use subtraction with idempotents and star projections. For idempotents `p,q`, `q - p` is idempotent when `p * q = p = q * p`. For star projections `p,q`, `q - p` is a star projection when either `p * q = p` or `q * p = p`. In a star-ordered ring, when `p * q = p` or `q * p = p` we get `p ≤ q`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra label:t-algebra$	70/0	Mathlib/Algebra/Order/Star/Basic.lean,Mathlib/Algebra/Ring/Idempotent.lean,Mathlib/Algebra/Star/StarProjection.lean	3	23	['github-actions', 'tb65536', 'themathqueen']	nobody	12-14455 12 days ago	26-62207 26 days ago	29-9969 29 days
27090	TerenceGitH author:TerenceGitH	feat(Topology, Archive/Examples): Kuratowski's closure-complement theorem (incl. sharpness)	This is the outcome of a course project at Heidelberg University: https://matematiflo.github.io/CompAssistedMath2025/ feat(Topology): Kuratowski's closure-complement theorem "Topology/Kuratowski.lean" proves Kuratowski's closure-complement theorem, which says that if one repeatedly applies the closure and complement operators to a set in a topological space, at most 14 distinct sets can be obtained. feat(Archive/Examples): sharpness of Kuratowski's closure-complement theorem: "Examples/Kuratowski.lean" gives an example of a so-called "14-set" in ℝ, from which exactly 14 distinct sets can be obtained. Co-authored-by: Luis Sand @luiis-sd Co-authored-by: Leon Müller @leondieprobifi Co-authored-by: Junyan Xu @alreadydone --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-topology	386/0	Archive.lean,Archive/Examples/Kuratowski.lean,Mathlib.lean,Mathlib/Topology/Kuratowski.lean	4	5	['alreadydone', 'github-actions', 'wwylele']	nobody	12-6858 12 days ago	13-10381 13 days ago	13-11724 13 days
27155	Pjotr5 author:Pjotr5	Proof of Shearers 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	1266/0	Mathlib.lean,Mathlib/Combinatorics/SimpleGraph/Triangle/IndependenceNumber.lean	2	1	['github-actions']	nobody	11-41745 11 days ago	11-41745 11 days ago	11-41800 11 days
26799	themathqueen author:themathqueen	feat(Analysis/VonNeumannAlgebra/Basic): idempotent in von Neumann algebra iff its range and kernel are invariant under commutant	This adds that an idempotent operator is in a von Neumann algebra iff its range and kernel are invariant under the commutant. (This is from leanprover-community/mathlib3/pull/18290.) --- - [ ] depends on: #25874 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor blocked-by-other-PR	265/16	Mathlib/Algebra/Group/Commute/Units.lean,Mathlib/Algebra/Lie/LieTheorem.lean,Mathlib/Algebra/Module/Submodule/Invariant.lean,Mathlib/Analysis/InnerProductSpace/Projection.lean,Mathlib/Analysis/VonNeumannAlgebra/Basic.lean,Mathlib/LinearAlgebra/GeneralLinearGroup.lean,Mathlib/LinearAlgebra/Projection.lean,Mathlib/Topology/Algebra/Module/LinearMap.lean	8	6	['github-actions', 'j-loreaux', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot', 'themathqueen']	nobody	11-31487 11 days ago	11-31506 11 days ago	5-16058 5 days
27200	rotarc75 author:rotarc75	feat(RingTheory/Ideal): oka predicates over ideals	This PR introduces the notion of Oka predicates over the ideals of a ring. We usually speak of [Oka families](https://stacks.math.columbia.edu/tag/05K9) but predicates seemed more in line with mathlib's conventions. Currently this notions isn't used anywhere but we plan to make an other PR that proves that is all prime ideals of a ring are finitely generated, then this ring is Noetherian. We can also use Oka predicates to simplify the existing proof of [`IsPrincipalIdealRing.of_prime`](https://leanprover-community.github.io/mathlib4_docs/Mathlib/RingTheory/PrincipalIdealDomainOfPrime.html#IsPrincipalIdealRing.of_prime). Co-authored-by: Anthony Fernandes --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra label:t-algebra$	53/0	Mathlib.lean,Mathlib/RingTheory/Ideal/Oka.lean	2	1	['github-actions']	nobody	10-43153 10 days ago	10-43153 10 days ago	10-44053 10 days
25248	xcloudyunx author:xcloudyunx	feat(Combinatorics/SimpleGraph): Add Subgraph.inclusion_edge_apply_coe and inclusion_edgeSet_apply_coe	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-combinatorics	12/0	Mathlib/Combinatorics/SimpleGraph/Subgraph.lean	1	3	['github-actions', 'pimotte', 'xcloudyunx']	nobody	9-78182 9 days ago	60-216 1 month ago	60-268 60 days
27226	xcloudyunx author:xcloudyunx	feat(Combinatorics/SimpleGraph): Add Subgraph.inclusion_edge_apply_coe and inclusion_edgeSet_apply_coe	This PR continues the work from #25248. Original PR: https://github.com/leanprover-community/mathlib4/pull/25248	new-contributor t-combinatorics	14/0	Mathlib/Combinatorics/SimpleGraph/Subgraph.lean	1	1	['github-actions']	nobody	9-76691 9 days ago	9-78110 9 days ago	9-78167 9 days
26089	WilliamCoram author:WilliamCoram	feat: restricted power series form a ring	We define restricted power series over a normed ring R, and show they form a ring when R has the ultrametric property This is an update of [#23338](https://github.com/leanprover-community/mathlib4/pull/23338) to meet new expectations of PRs from forks. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra t-number-theory label:t-algebra$	182/0	Mathlib/RingTheory/PowerSeries/Restricted.lean	1	7	['CBirkbeck', 'WilliamCoram', 'github-actions']	nobody	9-29513 9 days ago	9-29513 9 days ago	28-18947 28 days
27006	zhikaip author:zhikaip	refactor: crossProduct notation	Replace `×₃` with `⨯` (`\X` or `\crossproduct`), and manually deprecate the old syntax. See [#mathlib4 > Notation for crossProduct](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/Notation.20for.20crossProduct/with/520119542) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data new-contributor t-meta	37/22	Mathlib/Geometry/Euclidean/Angle/Unoriented/CrossProduct.lean,Mathlib/LinearAlgebra/CrossProduct.lean	2	10	['eric-wieser', 'github-actions', 'j-loreaux', 'kmill']	nobody	9-26072 9 days ago	15-11508 15 days ago	15-21534 15 days
26901	5hv5hvnk author:5hv5hvnk	added PolynomialDegree and its test	computer_degree implemented into simproc --- feat: add simprocs for polynomial degree computation should resolve #22219	new-contributor t-meta awaiting-author	198/0	Mathlib.lean,Mathlib/Tactic/Simproc/PolynomialDegree.lean,MathlibTest/polynomial_degree_simproc.lean	3	3	['5hv5hvnk', 'YaelDillies', 'github-actions']	nobody	8-50582 8 days ago	15-38255 15 days ago	2-71043 2 days
27245	rirarika author:rirarika	MvPolynomial.Irreducible	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra label:t-algebra$	88/0	Mathlib.lean,Mathlib/Algebra/MvPolynomial/Irreducible.lean	2	3	['alreadydone', 'github-actions', 'mbkybky']	nobody	8-26969 8 days ago	8-53458 8 days ago	8-53502 8 days
26962	themathqueen author:themathqueen	feat(Data/Nat/Fib/Basic): some API for `Nat.fib`	Added some helpful lemmas for `Nat.fib`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data new-contributor awaiting-author	24/0	Mathlib/Data/Nat/Fib/Basic.lean	1	7	['Ruben-VandeVelde', 'github-actions', 'themathqueen', 'vihdzp']	nobody	8-11767 8 days ago	8-11768 8 days ago	8-31586 8 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	148/0	Mathlib.lean,Mathlib/Topology/Subpath.lean	2	1	['github-actions']	nobody	8-5992 8 days ago	8-16623 8 days ago	8-16671 8 days
26793	FlAmmmmING author:FlAmmmmING	feat(Algebra/Group /ForwardDiff.lean): add five theorems for forward difference	--- [![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$	212/3	Mathlib/Algebra/Group/ForwardDiff.lean	1	35	['AntoineChambert-Loir', 'DAE123456', 'FlAmmmmING', 'Ruben-VandeVelde', 'github-actions', 'kckennylau', 'madvorak']	nobody	7-56973 7 days ago	8-69927 8 days ago	21-22415 21 days
27284	FernandoChu author:FernandoChu	Chore(CategoryTheory/MorphismProperty/MonoFactorization): Factor out mono factorizations	Factored out `MonoFactorisations` from the `Images` file; also rename it to `MonoFactorizations` so it's inline with the rest of Mathlib. I'm also sneaking in some very basic extremal epis results if you don't mind, these were meant to be used to prove ```lean instance (priority := 100) hasStrongEpiImages_of_hasPullbacks_of_hasEqualizers [HasPullbacks C] [HasEqualizers C] : HasStrongEpiImages C ``` Which I noticed too late already had a proof; I think the proof has been improved anyways, it's just `infer_instance` now.	new-contributor t-category-theory	419/259	Mathlib.lean,Mathlib/Algebra/Category/Grp/Images.lean,Mathlib/Algebra/Category/ModuleCat/Images.lean,Mathlib/AlgebraicTopology/SimplexCategory/Basic.lean,Mathlib/CategoryTheory/Abelian/Basic.lean,Mathlib/CategoryTheory/Category/Factorisation.lean,Mathlib/CategoryTheory/ConcreteCategory/EpiMono.lean,Mathlib/CategoryTheory/Limits/Preserves/Shapes/Images.lean,Mathlib/CategoryTheory/Limits/Shapes/ExtremalEpi.lean,Mathlib/CategoryTheory/Limits/Shapes/Images.lean,Mathlib/CategoryTheory/Limits/Shapes/Kernels.lean,Mathlib/CategoryTheory/Limits/Shapes/StrongEpi.lean,Mathlib/CategoryTheory/Limits/Shapes/ZeroMorphisms.lean,Mathlib/CategoryTheory/Limits/Types/Images.lean,Mathlib/CategoryTheory/MorphismProperty/MonoFactorization.lean,Mathlib/CategoryTheory/Sites/Subsheaf.lean,Mathlib/Order/Category/NonemptyFinLinOrd.lean,scripts/nolints_prime_decls.txt	18	1	['github-actions']	nobody	7-50176 7 days ago	7-52734 7 days ago	7-52785 7 days
27217	ctchou author:ctchou	feat(Combinatorics/HypergraphRamsey): Ramsey's theorem for hypergraphs	We prove Ramsey's theorem for infinite hypergraphs: for any colouring of the k-subsets of an infinite set S with a finite set of colours, there is an infinite subset T of S whose k-subsets all have the same colour. The finite versions will follow from compactness techniques, but aren't included here. (#12273 is the first step for this). The proof encodes k-subsets as order-embeddings from Fin k rather than as Finsets, as this makes things more convenient, and should extend better to generalizations like the canonical Ramsey theorem. This requires a small amount of API to be added, including some simple instances for `OrderEmbedding`. We also require a result saying that there is a list of all k-subsets of Nat for which the sequence of largest elements is monotone. We do this by adding some new material in Order.Extension.Linear, which has more general applications. --- Original PR: https://github.com/leanprover-community/mathlib4/pull/12773 - [ ] depends on: #27271 - [ ] depends on: #27233 - [x] depends on: #27211	large-import new-contributor blocked-by-other-PR	646/1	Mathlib.lean,Mathlib/Combinatorics/HypergraphRamsey.lean,Mathlib/Data/Finset/Sort.lean,Mathlib/Order/Extension/Linear.lean,Mathlib/Order/Hom/Basic.lean,Mathlib/Order/Interval/Finset/Defs.lean,Mathlib/Order/OrderIsoNat.lean,Mathlib/Order/RelClasses.lean	8	5	['ctchou', 'github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	7-15763 7 days ago	7-58555 7 days ago	2-27044 2 days
27233	ctchou author:ctchou	feat: prove some properties of linearly ordered tuples of a linearly ordered typeFin ordered tuple	Co-authored-by: Peter Nelson (original author) --- This is a part of PR #27217, which continues the work in PR #12773. The relevant comments made by @YaelDillies in #12773 have been addressed. - [x] depends on: #27211 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-order awaiting-author	57/0	Mathlib/Data/Finset/Sort.lean	1	10	['YaelDillies', 'ctchou', 'github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	7-15098 7 days ago	7-15098 7 days ago	0-48911 13 hours
26880	agjftucker author:agjftucker	feat(Calculus/FDeriv/Partial): `hasStrictFDerivAt_uncurry_coprod` concerning partial derivatives	Confident that other contributions will follow (e.g. #26300), I begin this file with only the result needed to apply the implicit function theorem to a curried function. --- - [x] depends on: #26742 [This dependency is very slight.] [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor	126/0	Mathlib.lean,Mathlib/Analysis/Calculus/FDeriv/Partial.lean	2	2	['github-actions', 'mathlib4-dependent-issues-bot']	nobody	7-9851 7 days ago	7-9851 7 days ago	11-1032 11 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	113/0	Mathlib/Data/Nat/Digits/Lemmas.lean	1	5	['github-actions', 'hugh-fox', 'kckennylau']	nobody	7-8754 7 days ago	8-72532 8 days ago	8-72579 8 days
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/)	new-contributor t-category-theory 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	360-52639 11 months ago	416-47685 1 year ago	1-20125 1 day
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	341-29938 11 months ago	346-46180 11 months ago	54-52408 54 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/)	new-contributor t-algebra t-topology merge-conflict awaiting-author label:t-algebra$	462/2	Mathlib/AlgebraicTopology/SimplicialSet.lean	1	15	['YaelDillies', 'jcommelin', 'jstoobysmith', 'kim-em', 'linesthatinterlace']	nobody	341-29772 11 months ago	372-31097 1 year ago	14-58814 14 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/)	new-contributor t-category-theory 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	305-55357 10 months ago	305-55357 10 months ago	0-0 0 seconds
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	305-15832 10 months ago	305-15832 10 months 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	297-11810 9 months ago	297-11810 9 months 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	297-11810 9 months ago	297-11811 9 months 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	297-11809 9 months ago	297-11809 9 months ago	0-613 10 minutes
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/)	new-contributor t-algebra t-topology t-category-theory merge-conflict WIP label:t-algebra$	720/0	Mathlib.lean,Mathlib/AlgebraicTopology/AugmentedSimplexCategory.lean,Mathlib/AlgebraicTopology/SimplicialObject.lean,Mathlib/Order/Category/FinLinOrd.lean	4	5	['TwoFX', 'YaelDillies', 'joelriou', 'jstoobysmith']	nobody	290-22008 9 months ago	290-22008 9 months ago	7-63215 7 days
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	279-34467 9 months ago	279-34467 9 months ago	6-8380 6 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	269-5777 8 months ago	295-60968 9 months 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	262-62743 8 months ago	262-62743 8 months 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	260-18864 8 months ago	260-18864 8 months 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	255-57696 8 months ago	unknown	unknown
18646	jxjwan author:jxjwan	feat(RingTheory): isotypic components	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra merge-conflict label:t-algebra$	308/0	Mathlib/Order/CompactlyGenerated/Basic.lean,Mathlib/RingTheory/Isotypic.lean,Mathlib/RingTheory/SimpleModule.lean	3	1	['github-actions']	nobody	243-40868 8 months ago	243-40868 8 months ago	20-16585 20 days
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	225-80113 7 months ago	232-29136 7 months ago	0-4534 1 hour
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	208-32544 6 months ago	253-48172 8 months ago	0-0 0 seconds
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	192-15725 6 months ago	192-15725 6 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	191-34811 6 months ago	191-34811 6 months ago	9-13962 9 days
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	191-34811 6 months ago	191-34811 6 months ago	0-1791 29 minutes
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	191-730 6 months ago	191-730 6 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	186-22389 6 months ago	186-22390 6 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	179-39737 5 months ago	179-39737 5 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	178-14170 5 months ago	178-14170 5 months ago	9-73631 9 days
14799	luigi-massacci author:luigi-massacci	feat(Analysis/MeanInequalities): Weighted QM-AM inequality	The inequality between the quadratic and arithmetic mean as a consequence of Jensen's inequality. Weighted version for positive real valued functions from a `Finset`. Fix notation for sums, switching to `∈` in place of `in`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-analysis easy merge-conflict awaiting-author	26/3	Mathlib/Analysis/MeanInequalities.lean	1	8	['YaelDillies', 'acmepjz', 'github-actions', 'luigi-massacci', 'vihdzp']	nobody	177-7341 5 months ago	177-7341 5 months ago	0-38862 10 hours
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	166-83447 5 months ago	166-83447 5 months ago	39-21495 39 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	162-31146 5 months ago	162-31146 5 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	151-83818 5 months ago	151-83818 5 months ago	0-13879 3 hours
22245	Champitoad author:Champitoad	feat(CategoryTheory/Subobject): add formalization of subobject classifier	This introduces a file `Classifier.lean` defining the notion `Classifier C` of subobject classifier in any category `C` with a terminal object, following Section I.3 of "Sheaves in Geometry and Logic" [MM92]. This is related to but independent from #21281, because our definition associates a characteristic map to every _subobject_ rather than every _monomorphism_. Adopting this "extensional" rather than "intensional" definition allows us to formalize the proof of Proposition 1 in [MM92, Section I.3] (`hasClassifier_isRepresentable_iff`), that `C` has a subobject classifier if and only if the subobjects presheaf `sub C` is representable. --- [![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	5219/2536	Cache/Hashing.lean,Cache/IO.lean,Cache/Lean.lean,Mathlib.lean,Mathlib/Algebra/Algebra/Defs.lean,Mathlib/Algebra/Category/AlgebraCat/Limits.lean,Mathlib/Algebra/Category/BoolRing.lean,Mathlib/Algebra/Category/FGModuleCat/Basic.lean,Mathlib/Algebra/Category/Grp/AB.lean,Mathlib/Algebra/Category/Grp/EpiMono.lean,Mathlib/Algebra/Category/HopfAlgebraCat/Monoidal.lean,Mathlib/Algebra/Category/ModuleCat/Abelian.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/Differentials/Basic.lean,Mathlib/Algebra/Category/ModuleCat/EpiMono.lean,Mathlib/Algebra/Category/ModuleCat/FilteredColimits.lean,Mathlib/Algebra/Category/ModuleCat/Kernels.lean,Mathlib/Algebra/Category/ModuleCat/Monoidal/Basic.lean,Mathlib/Algebra/Category/ModuleCat/Presheaf/Colimits.lean,Mathlib/Algebra/Category/ModuleCat/Presheaf/Limits.lean,Mathlib/Algebra/Category/ModuleCat/Subobject.lean,Mathlib/Algebra/Category/MonCat/FilteredColimits.lean,Mathlib/Algebra/Category/Ring/Colimits.lean,Mathlib/Algebra/Category/Ring/Limits.lean,Mathlib/Algebra/Group/Commute/Units.lean,Mathlib/Algebra/Group/Pointwise/Set/Card.lean,Mathlib/Algebra/Homology/ComplexShape.lean,Mathlib/Algebra/Homology/Double.lean,Mathlib/Algebra/Homology/HasNoLoop.lean,Mathlib/Algebra/Homology/Homotopy.lean,Mathlib/Algebra/Polynomial/Basic.lean,Mathlib/Algebra/Polynomial/Degree/Operations.lean,Mathlib/Algebra/Polynomial/Lifts.lean,Mathlib/Algebra/Polynomial/Sequence.lean,Mathlib/AlgebraicTopology/SimplexCategory/GeneratorsRelations/EpiMono.lean,Mathlib/Analysis/CStarAlgebra/Spectrum.lean,Mathlib/Analysis/Complex/AbelLimit.lean,Mathlib/Analysis/Complex/AbsMax.lean,Mathlib/Analysis/Complex/Angle.lean,Mathlib/Analysis/Complex/Arg.lean,Mathlib/Analysis/Complex/Basic.lean,Mathlib/Analysis/Complex/CauchyIntegral.lean,Mathlib/Analysis/Complex/Circle.lean,Mathlib/Analysis/Complex/Hadamard.lean,Mathlib/Analysis/Complex/Isometry.lean,Mathlib/Analysis/Complex/Liouville.lean,Mathlib/Analysis/Complex/LocallyUniformLimit.lean,Mathlib/Analysis/Complex/OpenMapping.lean,Mathlib/Analysis/Complex/Periodic.lean,Mathlib/Analysis/Complex/PhragmenLindelof.lean,Mathlib/Analysis/Complex/Positivity.lean,Mathlib/Analysis/Complex/Schwarz.lean,Mathlib/Analysis/Complex/UnitDisc/Basic.lean,Mathlib/Analysis/Complex/UpperHalfPlane/Exp.lean,Mathlib/Analysis/Complex/UpperHalfPlane/Metric.lean,Mathlib/Analysis/Fourier/AddCircle.lean,Mathlib/Analysis/Fourier/AddCircleMulti.lean,Mathlib/Analysis/Fourier/FourierTransformDeriv.lean,Mathlib/Analysis/Fourier/Inversion.lean,Mathlib/Analysis/Fourier/PoissonSummation.lean,Mathlib/Analysis/InnerProductSpace/TwoDim.lean,Mathlib/Analysis/MellinTransform.lean,Mathlib/Analysis/Normed/Group/Continuity.lean,Mathlib/Analysis/Normed/Lp/WithLp.lean,Mathlib/Analysis/PSeries.lean,Mathlib/Analysis/PSeriesComplex.lean,Mathlib/Analysis/SpecialFunctions/CompareExp.lean,Mathlib/Analysis/SpecialFunctions/Complex/Arctan.lean,Mathlib/Analysis/SpecialFunctions/Complex/Arg.lean,Mathlib/Analysis/SpecialFunctions/Complex/Circle.lean,Mathlib/Analysis/SpecialFunctions/Complex/Log.lean,Mathlib/Analysis/SpecialFunctions/Complex/LogBounds.lean,Mathlib/Analysis/SpecialFunctions/Exp.lean,Mathlib/Analysis/SpecialFunctions/Exponential.lean,Mathlib/Analysis/SpecialFunctions/Gamma/Basic.lean,Mathlib/Analysis/SpecialFunctions/Gamma/Beta.lean,Mathlib/Analysis/SpecialFunctions/Gamma/Deriv.lean,Mathlib/Analysis/SpecialFunctions/Gaussian/FourierTransform.lean,Mathlib/Analysis/SpecialFunctions/Gaussian/GaussianIntegral.lean,Mathlib/Analysis/SpecialFunctions/Gaussian/PoissonSummation.lean,Mathlib/Analysis/SpecialFunctions/ImproperIntegrals.lean,Mathlib/Analysis/SpecialFunctions/Integrals.lean,Mathlib/Analysis/SpecialFunctions/Log/Summable.lean,Mathlib/Analysis/SpecialFunctions/PolarCoord.lean,Mathlib/Analysis/SpecialFunctions/Pow/Asymptotics.lean,Mathlib/Analysis/SpecialFunctions/Pow/Continuity.lean,Mathlib/Analysis/SpecialFunctions/Pow/Deriv.lean,Mathlib/Analysis/SpecialFunctions/Pow/Real.lean,Mathlib/Analysis/SpecialFunctions/Trigonometric/ArctanDeriv.lean,Mathlib/Analysis/SpecialFunctions/Trigonometric/Basic.lean,Mathlib/Analysis/SpecialFunctions/Trigonometric/ComplexDeriv.lean,Mathlib/Analysis/SpecialFunctions/Trigonometric/Cotangent.lean,Mathlib/Analysis/SpecialFunctions/Trigonometric/Series.lean,Mathlib/CategoryTheory/Abelian/FreydMitchell.lean,Mathlib/CategoryTheory/Abelian/GrothendieckAxioms/Connected.lean,Mathlib/CategoryTheory/Abelian/GrothendieckAxioms/Indization.lean,Mathlib/CategoryTheory/Abelian/GrothendieckCategory/Coseparator.lean	205	10	['Champitoad', 'github-actions', 'joelriou']	nobody	151-7233 5 months ago	151-8506 5 months ago	0-38059 10 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	148-39744 4 months ago	148-39744 4 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	147-24055 4 months ago	147-24055 4 months ago	15-40648 15 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	144-68568 4 months ago	144-68568 4 months ago	92-44198 92 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	143-25758 4 months ago	143-25758 4 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	135-21584 4 months ago	135-21584 4 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	116-56983 3 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	111-51972 3 months ago	111-51972 3 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	111-1527 3 months ago	111-1527 3 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	108-34160 3 months ago	108-34161 3 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	107-36888 3 months ago	107-36888 3 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	100-8086 3 months ago	100-8086 3 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	100-4218 3 months ago	100-4218 3 months ago	13-60072 13 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	82-1336 2 months ago	82-1341 2 months ago	0-179 2 minutes
13685	niklasmohrin author:niklasmohrin	feat(Combinatorics): add definitions for network flows	Although we might not have any super-interesting results ready for mathlib yet, I feel that the definitions from this commit are already mature enough to include. These definitions are ported from last semester's work we did at https://github.com/niklasmohrin/lean-seminar-2023 and I have put some time in to refactor our code to `Int` and now to any parameter `R`. In the linked repository, there is some more stuff that I can send in. One obstacle without integer values is that it is not clear why a maximum flow would exist. I think the best way to tackle this would be to prove max-flow-min-cut theorem and implement the Ford-Fulkerson algorithm. It has been pointed out on Zulip that there is an [Isabelle formalization of the Edmonds Karp Algorithm](https://www.isa-afp.org/entries/EdmondsKarp_Maxflow.html). I feel that the definitions are pretty solid and it makes sense to include them, even if just for unifying definitions across downstream projects. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-combinatorics merge-conflict awaiting-author	244/0	Mathlib.lean,Mathlib/Combinatorics/Flow/Basic.lean,docs/references.bib	3	57	['Shreyas4991', 'YaelDillies', 'b-mehta', 'github-actions', 'leanprover-community-bot-assistant', 'madvorak', 'niklasmohrin']	nobody	72-79934 2 months ago	72-79936 2 months ago	86-21072 86 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	68-23942 2 months ago	68-23943 2 months ago	45-84611 45 days
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	90	['EtienneC30', 'b-mehta', 'github-actions', 'leanprover-community-bot-assistant', 'meithecatte', 'rudynicolop']	EtienneC30 assignee:EtienneC30	68-23016 2 months ago	68-23018 2 months ago	39-67601 39 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	60-19256 1 month ago	60-19258 1 month 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	49-77609 1 month ago	49-77611 1 month 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	42-70162 1 month ago	162-48124 5 months ago	27-65384 27 days
22639	b-reinke author:b-reinke	feat(Mathlib/GroupTheory/FreeGroup): theory of (cyclically) reduced words	Upstreamed from the [EquationalTheories](https://github.com/teorth/equational_theories) project. This PR defines in the new file `Mathlib/GroupTheory/FreeGroup/ReducedWords.lean` some extra lemmas for free groups, in particular about (cyclically) reduced words. ## Main declarations * `FreeGroup.Red.reduced`: the predicate for reduced words * `FreeGroup.Red.cyclicallyReduced`: the predicate for cyclically reduced words ## Main statements * `FreeGroup.infinite_order`: nontrivial elements of a free group have infinite order * `FreeGroup.zpow_left_injective`: taking n-th powers is an injective function on the free group Co-authored-by: Amir Livne Bar-on - [ ] depends on: #23366 - [ ] depends on: #23367 - [x] depends on: #23368 --- [![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$	429/0	Mathlib.lean,Mathlib/GroupTheory/FreeGroup/Basic.lean,Mathlib/GroupTheory/FreeGroup/Reduce.lean,Mathlib/GroupTheory/FreeGroup/ReducedWords.lean	4	3	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	40-25205 1 month ago	40-25208 1 month ago	20-75471 20 days
21603	imbrem author:imbrem	feat(CategoryTheory/ChosenFiniteProducts): add basic ChosenFiniteCoproducts class	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. [![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	261/2	Mathlib/CategoryTheory/ChosenFiniteProducts.lean	1	18	['TwoFX', 'YaelDillies', 'github-actions', 'grunweg', 'imbrem', 'joelriou', 'leanprover-community-bot-assistant', 'robin-carlier']	TwoFX and joelriou assignee:TwoFX assignee:joelriou	38-45444 1 month ago	72-12533 2 months ago	89-21170 89 days
19796	peakpoint author:peakpoint	feat: L'Hopital's rule from within a convex set	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-analysis merge-conflict	190/19	Mathlib/Algebra/Polynomial/Module/Basic.lean,Mathlib/Analysis/Calculus/LHopital.lean,Mathlib/Analysis/Convex/Topology.lean,Mathlib/Geometry/Manifold/Instances/Real.lean,Mathlib/Order/Interval/Set/Basic.lean	5	15	['RemyDegenne', 'github-actions', 'leanprover-community-bot-assistant', 'peakpoint', 'sgouezel']	sgouezel assignee:sgouezel	21-67960 21 days ago	21-67960 21 days ago	80-57750 80 days
22018	maddycrim author:maddycrim	feat(RingTheory/Localization/Pi): localization of a finite direct product where each semiring in product has maximal nilradical is a projection	For noncomputable def `surjectivePiNilradicalIsMaximal` : Let `M` be a submonoid of a direct product of commutative rings `R i`. If each `R i` has maximal nilradical then the direct product `∏ R i` surjects onto the localization of `∏ R i` at `M`. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import new-contributor t-algebra merge-conflict WIP label:t-algebra$	28/0	Mathlib/RingTheory/Localization/Pi.lean	1	29	['Paul-Lez', 'alreadydone', 'erdOne', 'github-actions', 'grunweg', 'jcommelin', 'kbuzzard', 'leanprover-community-bot-assistant', 'maddycrim']	mariainesdff assignee:mariainesdff	21-67711 21 days ago	21-67712 21 days ago	125-80931 125 days
23637	kirilvino author:kirilvino	feat(Combinatorics/SimpleGraph): every circuit contains a cycle proof	circuit to cycle proof --- This PR uses the bypass definition in a new function for closed walks that removes repeated vertices. Then proves if the closed walk given is a circuit, that the result from this function is a cycle. This is then packaged up similar to the existing ToPath definition, creating a way of transforming a circuit into a cycle. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-combinatorics merge-conflict awaiting-author	26/0	Mathlib/Combinatorics/SimpleGraph/Path.lean	1	9	['b-mehta', 'github-actions', 'kirilvino', 'leanprover-community-bot-assistant']	nobody	21-67571 21 days ago	21-67572 21 days ago	13-19789 13 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	21-66923 21 days ago	21-66924 21 days ago	6-51040 6 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 merge-conflict	17/5	Mathlib/Tactic/ComputeDegree.lean,MathlibTest/ComputeDegree.lean	2	3	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	21-66922 21 days ago	21-66923 21 days ago	38-26044 38 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	21-66919 21 days ago	21-66919 21 days ago	11-84822 11 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	3	['VTrelat', 'github-actions', 'leanprover-community-bot-assistant']	nobody	21-66912 21 days ago	21-66913 21 days ago	29-56208 29 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	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	21-66911 21 days ago	21-66911 21 days ago	29-51653 29 days
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	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	21-66911 21 days ago	21-66912 21 days ago	0-1523 25 minutes
25486	VTrelat author:VTrelat	feat(SetTheory/ZFC/Integers): define integers in ZFC	Extend the model of ZFC with integers following the converse direction as for naturals. We first define a type and then build a set. We finally show that both representations have coercions in both direction: - define a proper type `ZFInt` representing integers based on `ZFNat × ZFNat` and following the usual construction of integers - add theorems on usual algebraic properties of integers - define a set `Int` and show that it matches-i.e. that it is isomorphic to-the type `ZFInt` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) - [ ] depends on: #25483 - [ ] depends on: #25485	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	21-66910 21 days ago	21-66910 21 days ago	0-2067 34 minutes
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	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	21-66909 21 days ago	21-66909 21 days ago	0-1808 30 minutes
26178	ppls-nd-prs author:ppls-nd-prs	feat(CategoryTheory/Limits): Fubini for products	We show that the product of products is a product indexed by the sigma type. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-category-theory merge-conflict awaiting-author	17/0	Mathlib/CategoryTheory/Limits/Shapes/Products.lean	1	5	['chrisflav', 'github-actions', 'leanprover-community-bot-assistant', 'ppls-nd-prs', 'robin-carlier']	robin-carlier assignee:robin-carlier	21-64613 21 days ago	21-64614 21 days ago	0-47665 13 hours
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: #26534 [![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	21-64473 21 days ago	21-64473 21 days ago	0-5139 1 hour
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	17-74735 17 days ago	17-74736 17 days ago	8-28043 8 days
23949	Louddy author:Louddy	feat: SkewPolynomial	# Univariate skew polynomials Skew polynomials are represented as `SkewMonoidAlgebra R (Multiplicative ℕ)`, where `R` is usually at least a Semiring. In this file, we define `SkewPolynomial` and provide basic instances. This is currently missing the definition of `coeff` and `single` as they require a more advance interface of `SkewMonoidAlgebra` which is still WIP (See TODOs in file). Co-authored-by: María Inés de Frutos Fernández <[mariaines.dff@gmail.com](mailto:mariaines.dff@gmail.com)> --- - [x] depends on: #22078 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import new-contributor t-algebra merge-conflict label:t-algebra$	600/42	Mathlib.lean,Mathlib/Algebra/SkewMonoidAlgebra/Basic.lean,Mathlib/Algebra/SkewPolynomial/Basic.lean,docs/references.bib	4	3	['github-actions', 'leanprover-community-bot-assistant', 'mathlib4-dependent-issues-bot']	nobody	17-36195 17 days ago	17-36197 17 days ago	0-2389 39 minutes
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	17-36001 17 days ago	17-36003 17 days ago	179-12934 179 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
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/)	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	16	['b-mehta', 'github-actions', 'leanprover-bot', 'mathlib-bors', 'mattrobball']	nobody	99-24768 3 months ago	114-23572 3 months ago	0-5717 1 hour
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	79-2034 2 months ago	79-2034 2 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	79-1800 2 months ago	79-1800 2 months ago	47-32152 47 days
23137	grunweg author:grunweg	chore(Topology): some more fun_prop tagging	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology delegated	8/4	Mathlib/Dynamics/Flow.lean,Mathlib/Topology/Algebra/Monoid.lean	2	10	['github-actions', 'grunweg', 'j-loreaux', 'mathlib-bors']	nobody	78-4249 2 months ago	78-4249 2 months ago	34-32727 34 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	51-35823 1 month ago	51-36713 1 month ago	0-11212 3 hours
22366	kim-em author:kim-em	feat: `check_equalities` tactic for diagnosing defeq problems	The `check_equalities` tactic, which checks the typing of equalities in the goal, reporting discrepancies between the implicit type argument of the equality, and the inferred types of the left and right hand sides, at "instances and reducible" transparency. Reports from this tactic do not necessarily indicate a problem, although typically `simp` should reduce rather than increase the reported discrepancies. `check_equalities` may be useful in diagnosing uses of `erw`.	t-meta delegated	119/3	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	13	['adomani', 'b-mehta', 'eric-wieser', 'github-actions', 'grunweg', 'mathlib-bors']	nobody	50-53424 1 month ago	134-27636 4 months ago	15-14325 15 days
18693	Ruben-VandeVelde author:Ruben-VandeVelde	feat: add ConjRootClass	Co-authored-by: FR --- From #6718 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	new-contributor t-algebra delegated label:t-algebra$	213/0	Mathlib.lean,Mathlib/FieldTheory/Minpoly/ConjRootClass.lean,Mathlib/FieldTheory/Minpoly/IsConjRoot.lean	3	16	['LessnessRandomness', 'Vierkantor', 'alreadydone', 'github-actions', 'grunweg', 'mathlib-bors']	Vierkantor assignee:Vierkantor	50-53383 1 month ago	61-28936 2 months ago	94-8480 94 days
23240	urkud author:urkud	feat(Topology/Maps): `IsOpenMap` and `ClusterPt`	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology delegated	17/4	Mathlib/Topology/Maps/Basic.lean	1	8	['eric-wieser', 'github-actions', 'grunweg', 'mathlib-bors', 'urkud']	nobody	50-30745 1 month ago	124-86126 4 months ago	0-12104 3 hours
25262	Ruben-VandeVelde author:Ruben-VandeVelde	chore: add missing deprecations	From #23643, #23804, #24762, #24827, #24833, and #25016. --- Maybe for some of those there could be reasons to argue that a deprecation is not terribly useful, but adding them is so cheap that I don't think it's worth spending much time arguing about it. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	tech debt delegated	36/0	Mathlib/AlgebraicGeometry/IdealSheaf/Basic.lean,Mathlib/Analysis/SpecialFunctions/Complex/LogBounds.lean,Mathlib/Analysis/SpecialFunctions/MulExpNegMulSqIntegral.lean,Mathlib/GroupTheory/Perm/Finite.lean,Mathlib/GroupTheory/Perm/Support.lean,Mathlib/NumberTheory/NumberField/InfinitePlace/TotallyRealComplex.lean,Mathlib/RingTheory/Ideal/Operations.lean,Mathlib/RingTheory/MvPowerSeries/PiTopology.lean	8	5	['Vierkantor', 'github-actions', 'grunweg', 'mathlib-bors']	grunweg assignee:grunweg	46-52364 1 month ago	46-52364 1 month ago	12-61166 12 days
25765	JovanGerb author:JovanGerb	feat(gcongr): lemma for rewriting inside divisibility	TODO: add test to show that we can rewrite using `a ≡ b [ZMOD n]` inside `n ∣ 2 * a + 1`. edit: it's not yet entirely clear if this is the right thing to do. --- [![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	42-80660 1 month ago	43-29798 1 month ago	1-19951 1 day
26048	Vierkantor author:Vierkantor	script: Add downstream project dashboard	This is a Python script using the `downstream_repos.yml` file to check the technical setup of projects downstream from Mathlib: do they have tags for Lean toolchain releases, how do they run their CI and workflows, and how is linting and testing done? This should tell us at a glance which projects might benefit from CI expert attention. We have to add some more data in `downstream_repos.yml` (on workflow setup) but this should not need regular changes, since it is only a list of filenames. Some logic is shared between this script and `downstream-tags.py`. I could also merge the two (so that running `downstream-dashboard.py tag-name` works like `downstream-tags.py tag-name` does now). --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	delegated	352/0	scripts/downstream_dashboard.py,scripts/downstream_repos.yml	2	3	['github-actions', 'kim-em', 'mathlib-bors']	nobody	28-33735 28 days ago	33-36065 1 month ago	5-71932 5 days
24875	smmercuri author:smmercuri	feat: injectivity of `InfinitePlace.embedding`	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-number-theory delegated	19/0	Mathlib/NumberTheory/NumberField/InfinitePlace/Basic.lean	1	8	['Ruben-VandeVelde', 'github-actions', 'mathlib-bors', 'riccardobrasca', 'smmercuri', 'xroblot']	nobody	20-50255 20 days ago	20-50255 20 days ago	53-8275 53 days
23669	erdOne author:erdOne	feat(FieldTheory): abelian extensions	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra delegated label:t-algebra$	74/0	Mathlib.lean,Mathlib/FieldTheory/Galois/Abelian.lean,Mathlib/NumberTheory/Cyclotomic/Gal.lean	3	12	['acmepjz', 'alreadydone', 'chrisflav', 'erdOne', 'github-actions', 'mathlib-bors', 'riccardobrasca', 'xroblot']	riccardobrasca assignee:riccardobrasca	17-50456 17 days ago	18-39484 18 days ago	29-68817 29 days
25796	dagurtomas author:dagurtomas	feat(CategoryTheory): transport symmetric monoidal structure along equivalence	--- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/) --- This PR continues the work from #24490. Original PR: https://github.com/leanprover-community/mathlib4/pull/24490	t-category-theory delegated	100/0	Mathlib.lean,Mathlib/CategoryTheory/Monoidal/Braided/Basic.lean,Mathlib/CategoryTheory/Monoidal/Braided/Transport.lean	3	4	['github-actions', 'joelriou', 'mathlib-bors']	nobody	16-45449 16 days ago	16-45449 16 days ago	27-84690 27 days
25254	fpvandoorn author:fpvandoorn	fix: cleanup measurability + prod/sum lemmas + fun_prop	* Add `fun_prop` to a few more lemmas * Rename the compositional version to something without a prime, add the compositional version for `StronglyMeasurable` * use the `prod/fun_prod` naming scheme (the compositional version is called `prod_apply`) for `[AE][Strongly]Measurable` --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-measure-probability delegated	167/88	Mathlib/Analysis/FunctionalSpaces/SobolevInequality.lean,Mathlib/MeasureTheory/Constructions/BorelSpace/Real.lean,Mathlib/MeasureTheory/Function/Intersectivity.lean,Mathlib/MeasureTheory/Function/LpSpace/Complete.lean,Mathlib/MeasureTheory/Function/StronglyMeasurable/AEStronglyMeasurable.lean,Mathlib/MeasureTheory/Function/StronglyMeasurable/Basic.lean,Mathlib/MeasureTheory/Function/UniformIntegrable.lean,Mathlib/MeasureTheory/Group/Arithmetic.lean,Mathlib/MeasureTheory/Integral/DominatedConvergence.lean,Mathlib/MeasureTheory/Integral/Lebesgue/Add.lean,Mathlib/MeasureTheory/Integral/MeanInequalities.lean,Mathlib/MeasureTheory/Integral/Prod.lean,Mathlib/MeasureTheory/MeasurableSpace/Constructions.lean,Mathlib/MeasureTheory/MeasurableSpace/Embedding.lean,Mathlib/MeasureTheory/Measure/FiniteMeasure.lean,Mathlib/MeasureTheory/Measure/GiryMonad.lean,Mathlib/MeasureTheory/Measure/ProbabilityMeasure.lean,Mathlib/Probability/Independence/Conditional.lean,Mathlib/Probability/Independence/Kernel.lean,Mathlib/Probability/Integration.lean,Mathlib/Probability/Kernel/MeasurableIntegral.lean,Mathlib/Probability/Martingale/Basic.lean,Mathlib/Probability/Martingale/BorelCantelli.lean,Mathlib/Probability/Martingale/Centering.lean,Mathlib/Probability/Martingale/Upcrossing.lean,Mathlib/Probability/Moments/SubGaussian.lean,Mathlib/Probability/StrongLaw.lean	27	12	['RemyDegenne', 'fpvandoorn', 'github-actions', 'mathlib-bors', 'sgouezel']	nobody	11-12195 11 days ago	11-16419 11 days ago	1-49524 1 day
27241	alreadydone author:alreadydone	feat(MonoidAlgebra): generalize IsDomain instance	The instance works over a semiring with cancellative addition. It's then used to generalize the IsDomain instances on Polynomial and MvPolynomial. --- - [x] depends on: #27263 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-algebra delegated label:t-algebra$	78/69	Mathlib/Algebra/MonoidAlgebra/NoZeroDivisors.lean,Mathlib/Algebra/MvPolynomial/Basic.lean,Mathlib/Algebra/MvPolynomial/Funext.lean,Mathlib/Algebra/Polynomial/Basic.lean,Mathlib/Algebra/Polynomial/Degree/Domain.lean,Mathlib/FieldTheory/RatFunc/Defs.lean,Mathlib/LinearAlgebra/Matrix/Adjugate.lean,Mathlib/LinearAlgebra/Vandermonde.lean,Mathlib/RingTheory/Polynomial/Basic.lean	9	27	['YaelDillies', 'alreadydone', 'eric-wieser', 'github-actions', 'mathlib-bors', 'mathlib4-dependent-issues-bot']	nobody	4-84446 4 days ago	4-84446 4 days ago	3-64242 3 days
27324	luigi-massacci author:luigi-massacci	feat: HasCompactSupport.sub lemma (multiplicative & additive version)	Filled missing API, easy consequence from lemma for negation. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology easy delegated	6/0	Mathlib/Topology/Algebra/Support.lean	1	7	['ADedecker', 'eric-wieser', 'github-actions', 'grunweg', 'mathlib-bors']	grunweg assignee:grunweg	3-2044 3 days ago	5-30962 5 days ago	0-14941 4 hours
27303	kckennylau author:kckennylau	chore(Quot): fix `Quotient.liftOn₂_mk`	--- I myself was amazed that this has been here for so long, and I think it's because `simp` would just implicitly unfold it and just use the lemmas from `lift_mk`, so `simp` still managed to "solve" it. I tried to trace back the mistake, and I traced it all the way back to the [commit (exactly!) 5 years ago](https://github.com/leanprover-community/mathlib3/commit/501aeb7f4cf2dc38a83f93f4bb4f5df61348dadf) to mathlib3 where this mistake was introduced. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-data easy delegated	4/2	Mathlib/Data/Quot.lean	1	5	['ADedecker', 'eric-wieser', 'github-actions', 'mathlib-bors']	nobody	3-1919 3 days ago	5-30512 5 days ago	1-13111 1 day
26810	oliver-butterley author:oliver-butterley	feat (Mathlib/Dynamics/BirkhoffSum/Basic): add lemma `birkhoffSum_of_comp_eq`	If a function `φ` is invariant under a function `f` (i.e., `φ ∘ f = φ`), then the Birkhoff sum of `φ` over `f` for `n` iterations is equal to `n • φ`. Co-authored-by: Lua Viana Reis --- - [x] depends on: #26807 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-dynamics easy delegated	9/0	Mathlib/Dynamics/BirkhoffSum/Basic.lean	1	6	['ADedecker', 'Ruben-VandeVelde', 'github-actions', 'mathlib-bors', 'mathlib4-dependent-issues-bot', 'oliver-butterley']	nobody	1-50443 1 day ago	1-50443 1 day ago	17-19827 17 days
25715	kbuzzard author:kbuzzard	feat: more RestrictedProduct API	A constructor, more algebra boilerplate (e.g. `SMul ℕ` on a restricted product of `AddMonoid`s, restricted product of `CommMonoid`s is a `CommMonoid`, restricted product of `R`-modules wrt `R`-submodules is an `R`-module, variant of `map` when the index set doesn't change. From the FLT project. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	FLT t-topology delegated	105/46	Mathlib/Topology/Algebra/RestrictedProduct/Basic.lean,Mathlib/Topology/Algebra/RestrictedProduct/TopologicalSpace.lean	2	17	['ADedecker', 'github-actions', 'kbuzzard', 'mathlib-bors', 'matthewjasper']	nobody	1-43173 1 day ago	1-43173 1 day ago	43-45088 43 days
27462	sgouezel author:sgouezel	chore: scope the instances giving a normed space structure from a Riemannian bundle instance	These are costly and quite specific. See discussion at [#mathlib4 > type-class inference slow/timing out @ 💬](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/type-class.20inference.20slow.2Ftiming.20out/near/530312318) --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-topology delegated	21/11	Mathlib/Analysis/NormedSpace/OperatorNorm/NormedSpace.lean,Mathlib/Geometry/Manifold/Riemannian/Basic.lean,Mathlib/Geometry/Manifold/VectorBundle/Riemannian.lean,Mathlib/Topology/VectorBundle/Riemannian.lean	4	9	['PatrickMassot', 'eric-wieser', 'github-actions', 'grunweg', 'leanprover-bot', 'mathlib-bors']	nobody	1-39292 1 day ago	1-39774 1 day ago	0-5389 1 hour
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	293-43830 9 months ago	295-67306 9 months 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	113-30174 3 months ago	113-30174 3 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	71-24196 2 months ago	71-24198 2 months ago	82-54712 82 days
24409	urkud author:urkud	chore(*): fix `nmem` vs `not_mem` names	--- There are some missing/buggy deprecations, I'm going to fix them later today or tomorrow. [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	awaiting-zulip tech debt merge-conflict delegated awaiting-author	317/176	Mathlib/Algebra/BigOperators/Finprod.lean,Mathlib/Algebra/BigOperators/Group/Finset/Lemmas.lean,Mathlib/Algebra/Group/Indicator.lean,Mathlib/Algebra/Group/Support.lean,Mathlib/Algebra/GroupWithZero/NonZeroDivisors.lean,Mathlib/Algebra/Order/Group/Indicator.lean,Mathlib/Algebra/Polynomial/AlgebraMap.lean,Mathlib/Algebra/Polynomial/Degree/Operations.lean,Mathlib/Analysis/Calculus/BumpFunction/Basic.lean,Mathlib/Analysis/Calculus/DSlope.lean,Mathlib/Analysis/Calculus/Deriv/Basic.lean,Mathlib/Analysis/Calculus/Deriv/Support.lean,Mathlib/Analysis/Calculus/FDeriv/Basic.lean,Mathlib/Analysis/Calculus/Rademacher.lean,Mathlib/Analysis/Complex/RemovableSingularity.lean,Mathlib/Analysis/Convex/Cone/InnerDual.lean,Mathlib/Analysis/Convex/Cone/Proper.lean,Mathlib/Analysis/Convolution.lean,Mathlib/Analysis/Distribution/AEEqOfIntegralContDiff.lean,Mathlib/Data/LocallyFinsupp.lean,Mathlib/Data/Set/Basic.lean,Mathlib/Data/Set/Insert.lean,Mathlib/Dynamics/Ergodic/Conservative.lean,Mathlib/Dynamics/Ergodic/Ergodic.lean,Mathlib/Dynamics/Ergodic/Function.lean,Mathlib/Dynamics/PeriodicPts/Defs.lean,Mathlib/Geometry/Manifold/ContMDiff/Basic.lean,Mathlib/Geometry/Manifold/PartitionOfUnity.lean,Mathlib/GroupTheory/CosetCover.lean,Mathlib/LinearAlgebra/Dual/Lemmas.lean,Mathlib/LinearAlgebra/FreeModule/PID.lean,Mathlib/LinearAlgebra/PID.lean,Mathlib/LinearAlgebra/RootSystem/Base.lean,Mathlib/LinearAlgebra/RootSystem/Finite/Lemmas.lean,Mathlib/MeasureTheory/Function/ContinuousMapDense.lean,Mathlib/MeasureTheory/Function/ConvergenceInMeasure.lean,Mathlib/MeasureTheory/Function/L2Space.lean,Mathlib/MeasureTheory/Function/LocallyIntegrable.lean,Mathlib/MeasureTheory/Function/LpSpace/Indicator.lean,Mathlib/MeasureTheory/Integral/Average.lean,Mathlib/MeasureTheory/Integral/Bochner/Set.lean,Mathlib/MeasureTheory/Integral/Layercake.lean,Mathlib/MeasureTheory/Integral/Lebesgue/Add.lean,Mathlib/MeasureTheory/Integral/Lebesgue/Basic.lean,Mathlib/MeasureTheory/Integral/RieszMarkovKakutani/Basic.lean,Mathlib/MeasureTheory/Integral/RieszMarkovKakutani/Real.lean,Mathlib/MeasureTheory/Measure/AbsolutelyContinuous.lean,Mathlib/MeasureTheory/Measure/AddContent.lean,Mathlib/MeasureTheory/Measure/DiracProba.lean,Mathlib/MeasureTheory/Measure/Haar/Unique.lean,Mathlib/MeasureTheory/Measure/Restrict.lean,Mathlib/MeasureTheory/Measure/WithDensity.lean,Mathlib/MeasureTheory/OuterMeasure/AE.lean,Mathlib/MeasureTheory/SetSemiring.lean,Mathlib/Order/Filter/AtTopBot/CountablyGenerated.lean,Mathlib/Order/Filter/Cocardinal.lean,Mathlib/Order/Filter/Cofinite.lean,Mathlib/Order/Filter/Tendsto.lean,Mathlib/Order/Filter/Ultrafilter/Basic.lean,Mathlib/Probability/Distributions/Uniform.lean,Mathlib/Probability/Kernel/Basic.lean,Mathlib/Probability/Kernel/Composition/MeasureCompProd.lean,Mathlib/RingTheory/AdicCompletion/LocalRing.lean,Mathlib/RingTheory/Ideal/Maximal.lean,Mathlib/RingTheory/LaurentSeries.lean,Mathlib/RingTheory/MvPolynomial/Symmetric/NewtonIdentities.lean,Mathlib/RingTheory/MvPowerSeries/NoZeroDivisors.lean,Mathlib/RingTheory/Spectrum/Maximal/Localization.lean,Mathlib/RingTheory/Spectrum/Prime/RingHom.lean,Mathlib/RingTheory/Spectrum/Prime/Topology.lean,Mathlib/Topology/Algebra/InfiniteSum/Group.lean,Mathlib/Topology/Algebra/Module/Cardinality.lean,Mathlib/Topology/Algebra/Support.lean,Mathlib/Topology/Bases.lean,Mathlib/Topology/ContinuousMap/BoundedCompactlySupported.lean,Mathlib/Topology/Order/Basic.lean,Mathlib/Topology/UrysohnsLemma.lean	77	4	['b-mehta', 'github-actions', 'jcommelin', 'leanprover-community-bot-assistant', 'mathlib-bors']	nobody	54-58914 1 month ago	54-58914 1 month ago	0-55045 15 hours
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	45-77485 1 month ago	45-77486 1 month ago	34-82472 34 days
19633	grunweg author:grunweg	fix(CI): build the Archive and Counterexamples with --wfail also	This appears to be an oversight --- which has no consequences right now (the check for noisy output later would catch any warnings), but fixing it doesn't hurt either. [Zulip discussion](https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/No.20.60--wfail.60.20when.20building.20archive). --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	CI awaiting-CI easy merge-conflict delegated	20/8	.github/build.in.yml,.github/workflows/bors.yml,.github/workflows/build.yml,.github/workflows/build_fork.yml	4	7	['adomani', 'bryangingechen', 'github-actions', 'grunweg', 'kim-em', 'leanprover-community-bot-assistant', 'mathlib-bors']	bryangingechen assignee:bryangingechen	22-73954 22 days ago	50-69019 1 month ago	7-42070 7 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	21-68084 21 days ago	21-68084 21 days 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	14-75799 14 days ago	15-18423 15 days ago	2-60107 2 days
25941	erdOne author:erdOne	feat(AlgebraicGeometry): inverse limits and schemes of finite type	We prove the following: Given a cofiltered diagram `D` of quasi-compact `S`-schemes with affine transition maps, and another scheme `X` of finite type over `S`. Then the canonical map `colim Homₛ(Dᵢ, X) ⟶ Homₛ(lim Dᵢ, X)` is injective. Co-authored-by: Christian Merten --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	large-import t-algebraic-geometry merge-conflict delegated	368/3	Mathlib/AlgebraicGeometry/AffineTransitionLimit.lean,Mathlib/AlgebraicGeometry/Morphisms/Affine.lean,Mathlib/AlgebraicGeometry/Morphisms/FiniteType.lean,Mathlib/CategoryTheory/Limits/Constructions/Over/Connected.lean,Mathlib/CategoryTheory/Limits/Creates.lean	5	23	['chrisflav', 'erdOne', 'github-actions', 'jcommelin', 'leanprover-community-bot-assistant', 'mathlib-bors']	nobody	3-38158 3 days ago	3-38159 3 days ago	17-3559 17 days
23528	Ruben-VandeVelde author:Ruben-VandeVelde	feat: add isOpen_setOf_affineIndependent	From sphere-eversion. --- [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/from-referrer/)	t-analysis merge-conflict delegated	15/0	Mathlib/Analysis/Normed/Module/FiniteDimension.lean	1	5	['github-actions', 'grunweg', 'leanprover-community-bot-assistant', 'mathlib-bors', 'urkud']	nobody	2-20902 2 days ago	2-20903 2 days ago	26-70139 26 days