Topological Neighborhood

tags:definition |topology

Neighborhood

Context

Statements

Definition (@Tu11, pp. 318). Let $(X,\tau )$ be a topological space, a set $N$ is said to be a neighborhood of a point $p\in X$, denoted as $N(x)$ if there exists an open set $U$ of $X$ such that $p\in U\subseteq N\subseteq X$.