\begin{definition}[Definition:Adherent Point/Definition 3]
Let $T = \struct{S, \tau}$ be a topological space.
Let $H \subseteq S$.
A point $x \in S$ is an '''adherent point of $H$''' {{iff}} every neighborhood $N$ of $x$ satisfies:
:$H \cap N \ne \O$
\end{definition}