\begin{definition}[Definition:Exterior Point (Complex Analysis)/Definition 2]
Let $S \subseteq \C$ be a subset of the complex plane.
Let $z_0 \in \C$.
$z_0$ is an '''exterior point''' of $S$ {{iff}}:
:$z_0$ is not an interior point of $S$
and:
:$z_0$ is not a boundary point of $S$.
\end{definition}