Neighborhood
A set N is a neighborhood of x exactly when N contains an open set containing x; N itself need not be open.
atlas-neighborhood · canonical_mko
This English edition is an AI candidate and does not yet have an OCME Atlas (GPT-6) Twin closure receipt.
Catalogue presentation and source-binding data
A set N is a neighborhood of x exactly when N contains an open set containing x; N itself need not be open.
atlas-neighborhood · canonical_mko