-
Notifications
You must be signed in to change notification settings - Fork 355
New issue
Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.
By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.
Already on GitHub? Sign in to your account
[Merged by Bors] - feat: A disjoint union is finite iff all sets are finite, and all but finitely many are empty #20457
Conversation
PR summary 65de0a4387Import changes for modified filesNo significant changes to the import graph Import changes for all files
|
Co-authored-by: Eric Wieser <[email protected]>
Thanks for the review! |
Mathlib/Data/Set/Finite/Lattice.lean
Outdated
finitely many are empty. -/ | ||
lemma PairwiseDisjoint.finite_biUnion_iff {f : β → Set α} {s : Set β} | ||
(hs : s.PairwiseDisjoint f) : | ||
Set.Finite (⋃ i ∈ s, f i) |
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
I'd liked to have seen this be of the more general form
Set.Finite (⋃ i ∈ s, f i) | |
Set.Finite (⋃ (i) (h : i ∈ s, f i h) |
but I guess the definition of PairwiseDisjoint
doesn't permit this; so no action needed.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
bors d+
Consider waiting a day or two to let @YaelDillies have a look for any other API like elim_set
that can make this more concise
✌️ sgouezel can now approve this pull request. To approve and merge a pull request, simply reply with |
Co-authored-by: Yaël Dillies <[email protected]>
bors r+ |
… finitely many are empty (#20457) From the Carleson project
Pull request successfully merged into master. Build succeeded: |
* origin/master: (189 commits) chore(Algebra): make more names consistent (#20449) feat: Polynomial FLT (#18882) feat: A disjoint union is finite iff all sets are finite, and all but finitely many are empty (#20457) fix: linkfix in 100.yaml (#20517) feat(1000): fill in more entries (#20470) feat(Combinatorics/SimpleGraph/Walk): add `penultimate` and `snd` (#16769) feat(ContinuousMultilinearMap): add lemmas about `.prod` (#20462) feat(RingTheory): classification of etale algebras over fields (#20324) fix: Allow multiple builds on staging branch (#20515) feat(CategoryTheory/Shift/Adjunction): properties of `Adjunction.CommShift` (#20337) chore(Data/Multiset/Basic): move the `sub`, `union`, `inter` sections lower (#19863) chore(Topology/UniformSpace/Completion): make coe' argument implicit (#20514) refactor(Algebra/Category/Grp/Colimits): change the construction of colimits in `AddCommGrp` (#20474) feat(Topology/Algebra/InfiniteSum/NatInt): Add pnat lems (#16544) chore(RingTheory/Finiteness): rename Module.Finite.out (#20506) refactor(CategoryTheory/Limits/Preserves/Ulift): simplify the proof that the universe lifting functor for types preserves all colimits (#20508) feat(CategoryTheory): products in the category of Ind-objects (#20507) chore: remove >9 month old deprecations (#20505) chore(FieldTheory/Galois): small cleanup (#20217) chore(LinearIndependent): generalize to semirings (#20480) chore(NumberTheory/NumberField/AdeleRing): refactor adele rings (#20500) chore: replace `aesop` with `simp` where possible (#20483) chore(1000): remove nonexistent fields (#20493) chore(CategoryTheory/Adjunction.Basic, CategoryTheory/Equivalence): change definition of `Adjunction.comp` and `Equivalence.trans` (#20490) feat(Asymptotics): add `Asymptotics.*.*Prod` lemmas (#20458) feat: a conditional kernel is almost everywhere a probability measure (#20430) feat: if `f` is a measurable group hom, then every point has a neighborhood `s` such that `f '' s` is bounded (#20304) feat: `Ico`, `Ioc`, and `Ioo` are not closed or compact (#20479) chore: drop redundant hypothesis in `Module.Dual.eq_of_preReflection_mapsTo` (#20492) feat(FaaDiBruno): derive `DecidableEq` (#20482) chore(SetTheory/Ordinal/Basic): `{x // x < y}` → `Iio y` (#20413) chore: generalize `FormalMultilinearSeries.ofScalars_norm` to `Seminormed` (#20351) chore(MvPolynomial/Localization): golf using TensorProduct (#20309) chore(Combinatorics/Enumerative/Partition): auto-derive DecidableEq (#20277) chore(CategoryTheory): make relevant parameters explicit in `Arrow.homMk`. (#20259) feat: add `IsStarNormal (↑x⁻¹ : R)` instance for `x : Rˣ` (#20091) fix: Stop cancelling builds of master (#20435) chore: update Mathlib dependencies 2025-01-05 (#20485) feat(SetTheory/Cardinal/Arithmetic): miscellaneous cardinality lemmas (#18933) chore: bump toolchain to v4.16.0-rc1, and merge bump/v4.16.0 (#20464) chore: bot validates lean-toolchain on bump/v4.X.0 branches (#20478) feat: shorthand lemmas for the L1 norm (#20383) chore: remove unnecessary adaptation notes (#20467) chore(Algebra/Category/MonCat/Colimits): remove smallness condition (#20473) chore(SetTheory/Ordinal/Arithmetic): `IsLeftCancelAdd Ordinal` (#19888) feat(Algebra): more on `OrthogonalIdempotents` (#18195) feat(Radical): `(radical a).natDegree ≤ a.natDegree` (#20468) feat(Polynomial): `(a^n)' = 0` iff `a' = 0` when `n` doesn't divide the characteristic (#20190) feat(Algebra/Lie): add Lie's theorem (#13480) chore(RingTheory/Generators): make algebra instance a def (#14265) ...
From the Carleson project