Definition:Interior Point (Topology)/Definition 1

Definition
Let $T = \struct {S, \tau}$ be a topological space.

Let $H \subseteq S$.

Let $h \in H$.

Then $h$ is an interior point of $H$ :
 * $h \in H^\circ$

where $H^\circ$ denotes the interior of $H$.

Also see

 * Equivalence of Definitions of Interior Point