nhdsSet_insert

∀ {X : Type u_2} [inst : TopologicalSpace X] (x : X) (s : Set X), nhdsSet (insert x s) = nhds x ⊔ nhdsSet s

Defined in: Mathlib.Topology.NhdsSet
Cited by: 4 results in Mathlib
Foundations: Depth 52 from the axioms · uses propext, Classical.choice, Quot.sound
Assumes: TopologicalSpace

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