ThmDex – An index of mathematical definitions, results, and conjectures.
F9304
Formulation 1
Let $X$ be a D11: Set such that
(i) $f : X \to \{ \{ x \} : x \in X \}$ is the D4493: Canonical singleton map on $X$
Then $f$ is a D468: Bijective map from $X$ to $\{ \{ x \} : x \in X \}$.