Theorems · Theorem · general topology
IsLindelof.diff
∀ {X : Type u} [inst : TopologicalSpace X] {s t : Set X}, IsLindelof s → IsOpen t → IsLindelof (s \ t)The set difference of a Lindelöf set and an open set is a Lindelöf set.
- Defined in
- Mathlib.Topology.Compactness.Lindelof
- Cited by
- 0 results in Mathlib
- Foundations
- Depth 77 from the axioms · uses propext, Classical.choice, Quot.sound
- Assumes
- TopologicalSpace
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Cites6
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
- IsOpenstatement and proof · cited by 2,400
- IsLindelofstatement and proof · cited by 85
- isClosed_compl_iffproof · cited by 35
- IsLindelof.inter_rightproof · cited by 4
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