ThmDex – An index of mathematical definitions, results, and conjectures.
F6537
Formulation 0
Let $M = (X, \mathcal{T}, d)$ be a D1107: Metric space such that
(i) $E \subseteq X$ is a D78: Subset of $X$
(ii) $E$ is a D17: Finite set
Then \begin{equation} X \setminus E \in \mathcal{T} \end{equation}