isClopen_inter_of_disjoint_cover_clopen

∀ {X : Type u} [inst : TopologicalSpace X] {s a b : Set X},
  IsClopen s → s ⊆ a ∪ b → IsOpen a → IsOpen b → Disjoint a b → IsClopen (s ∩ a)

The intersection of a disjoint covering by two open sets of a clopen set will be clopen.

Defined in: Mathlib.Topology.Clopen
Cited by: 3 results in Mathlib
Foundations: Depth 63 from the axioms · uses propext, Classical.choice, Quot.sound
Assumes: TopologicalSpace

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