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porting-notesMathlib3 to Mathlib4 porting notes.Mathlib3 to Mathlib4 porting notes.
Description
Classifies porting notes claiming added proof.
Examples
mathlib4/Mathlib/Topology/Compactness/Paracompact.lean
Lines 97 to 113 in f5e69ec
| /-- In a paracompact space, every open covering of a closed set admits a locally finite refinement | |
| indexed by the same type. -/ | |
| theorem precise_refinement_set [ParacompactSpace X] {s : Set X} (hs : IsClosed s) (u : ι → Set X) | |
| (uo : ∀ i, IsOpen (u i)) (us : s ⊆ ⋃ i, u i) : | |
| ∃ v : ι → Set X, (∀ i, IsOpen (v i)) ∧ (s ⊆ ⋃ i, v i) ∧ LocallyFinite v ∧ ∀ i, v i ⊆ u i := by | |
| -- Porting note: Added proof of uc | |
| have uc : (iUnion fun i => Option.elim' sᶜ u i) = univ := by | |
| apply Subset.antisymm (subset_univ _) | |
| · simp_rw [← compl_union_self s, Option.elim', iUnion_option] | |
| apply union_subset_union_right sᶜ us | |
| rcases precise_refinement (Option.elim' sᶜ u) (Option.forall.2 ⟨isOpen_compl_iff.2 hs, uo⟩) | |
| uc with | |
| ⟨v, vo, vc, vf, vu⟩ | |
| refine' ⟨v ∘ some, fun i ↦ vo _, _, vf.comp_injective (Option.some_injective _), fun i ↦ vu _⟩ | |
| · simp only [iUnion_option, ← compl_subset_iff_union] at vc | |
| exact Subset.trans (subset_compl_comm.1 <| vu Option.none) vc | |
| #align precise_refinement_set precise_refinement_set |
| /-- (Impl) A preliminary definition to avoid timeouts. -/ | |
| @[simps] | |
| def conesEquivFunctor (B : C) {J : Type w} (F : Discrete J ⥤ Over B) : | |
| Cone (widePullbackDiagramOfDiagramOver B F) ⥤ Cone F where | |
| obj c := | |
| { pt := Over.mk (c.π.app none) | |
| π := | |
| { app := fun ⟨j⟩ => Over.homMk (c.π.app (some j)) (c.w (WidePullbackShape.Hom.term j)) | |
| -- Porting note: Added a proof for `naturality` | |
| naturality := fun ⟨X⟩ ⟨Y⟩ ⟨⟨f⟩⟩ => by dsimp at f ⊢; aesop_cat } } |
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porting-notesMathlib3 to Mathlib4 porting notes.Mathlib3 to Mathlib4 porting notes.