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Isolated point
Formulation 0
Let $T = (X, \mathcal{T})$ be a D1106: Topological space.
A D2218: Set element $x \in X$ is an isolated point of $E \subseteq X$ in $T$ if and only if \begin{equation} \exists \, U \in \mathcal{T} : U \cap E = \{ x \} \end{equation}
Child definitions
» D3876: Set of isolated points