ThmDex – An index of mathematical definitions, results, and conjectures.
F8945
Formulation 0
Let $T = (X, \mathcal{T})$ be a D1106: Topological space such that
(i) $E \subseteq X$ is a D78: Subset of $X$
Then \begin{equation} \text{int} \langle E \rangle \subseteq E \end{equation}