diff --git a/Mathlib/Topology/Constructible.lean b/Mathlib/Topology/Constructible.lean index e509425470531..9342e488c1afd 100644 --- a/Mathlib/Topology/Constructible.lean +++ b/Mathlib/Topology/Constructible.lean @@ -344,9 +344,10 @@ lemma IsConstructible.induction_of_isTopologicalBasis {ι : Type*} [Nonempty ι] basis.isConstructible compact_inter _)) (union : ∀ s hs t ht, P s hs → P t ht → P (s ∪ t) (hs.union ht)) (s : Set X) (hs : IsConstructible s) : P s hs := by - induction hs using BooleanSubalgebra.closure_sdiff_sup_induction with - | sup => exact fun s hs t ht ↦ ⟨hs.1.union ht.1, hs.2.union ht.2⟩ - | inf => exact fun s hs t ht ↦ ⟨hs.1.inter ht.1, hs.2.inter_isOpen ht.2 ht.1⟩ + induction s, hs using BooleanSubalgebra.closure_sdiff_sup_induction with + | isSublattice => + exact ⟨fun s hs t ht ↦ ⟨hs.1.union ht.1, hs.2.union ht.2⟩, + fun s hs t ht ↦ ⟨hs.1.inter ht.1, hs.2.inter_isOpen ht.2 ht.1⟩⟩ | bot_mem => exact ⟨isOpen_empty, .empty⟩ | top_mem => exact ⟨isOpen_univ, .univ⟩ | sdiff U hU V hV => @@ -365,7 +366,7 @@ lemma IsConstructible.induction_of_isTopologicalBasis {ι : Type*} [Nonempty ι] (sdiff _ _ ht) (ih ⟨isOpen_biUnion fun _ _ ↦ basis.isOpen ⟨_, rfl⟩, .biUnion hs fun i _ ↦ basis.isRetrocompact compact_inter _⟩) - | sup' s _ t _ hs' ht' => exact union _ _ _ _ hs' ht' + | sup s _ t _ hs' ht' => exact union _ _ _ _ hs' ht' end CompactSpace