IsCountablyCompact.union

∀ {E : Type u_2} [inst : TopologicalSpace E] {A B : Set E},
  IsCountablyCompact A → IsCountablyCompact B → IsCountablyCompact (A ∪ B)

The union of two countably compact sets is countably compact.

Defined in: Mathlib.Topology.Compactness.CountablyCompact
Cited by: 1 results in Mathlib
Foundations: Depth 94 from the axioms · uses propext, Classical.choice, Quot.sound
Assumes: TopologicalSpace

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