Mathlib Map

Theorems · Definition · general topology

nhdsSetWithin

{X : Type u_1} → [TopologicalSpace X] → Set X → Set X → Filter X

The "neighbourhood within" filter for sets. Elements of 𝓝[t] s are sets containing the intersection of t and a neighbourhood of s.

Defined in
Mathlib.Topology.Defs.Filter
Cited by
25 results in Mathlib
Foundations
Depth 48 from the axioms · uses propext, Quot.sound
Assumes
TopologicalSpace

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Cited by25

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