Theorems · Theorem · general topology
Set.isCompact_sigma
∀ {ι : Type u_1} {X : ι → Type u_2} [inst : (i : ι) → TopologicalSpace (X i)] {s : Set ι} {t : (i : ι) → Set (X i)},
s.Finite → (∀ i ∈ s, IsCompact (t i)) → IsCompact (s.sigma t)- Defined in
- Mathlib.Topology.Compactness.Compact
- Cited by
- 1 results in Mathlib
- Foundations
- Depth 82 from the axioms · uses propext, Classical.choice, Quot.sound
- Assumes
- TopologicalSpace
Around this declaration
Dashed lines are statement dependencies; solid lines are citations in proofs.
Cites9
Mathlib declarations this one mentions in its statement or cites explicitly in its proof. Plumbing is filtered out.
- Setstatement and proof · cited by 53,352
- TopologicalSpacestatement and proof · cited by 24,529
- Set.Finitestatement and proof · cited by 1,814
- IsCompactstatement and proof · cited by 1,282
- IsCompact.imageproof · cited by 105
- Set.sigmastatement · cited by 65
- Set.Finite.isCompact_biUnionproof · cited by 11
- continuous_sigmaMkproof · cited by 8
- Set.sigma_eq_biUnionproof · cited by 1
Cited by1
Results whose statement or proof uses this declaration.
- IsCompactOpenCovered.iff_isCompactOpenCovered_sigmaMkproof · cited by 3