Let $T = (X, \mathcal{T})$ be a D784: Fréchet topological space.
Let $E \subseteq X$ be a D17: Finite set.
Let $E \subseteq X$ be a D17: Finite set.
Then
(1) | $E$ is a D98: Closed set in $T$ |
(2) | $X \setminus E$ is a D97: Open set in $T$ |