Definition:Interior (Topology)

Definition
Let $$T$$ be a topological space.

Let $$H \subseteq T$$.

The interior of $$H$$ is the union of all subsets of $$H$$ which are open in $$T$$.

It can be denoted:
 * $$\operatorname{Int} \left({H}\right)$$
 * $$H^\circ$$