ThmDex – An index of mathematical definitions, results, and conjectures.
Set of symbols
Deduction system
Zermelo-Fraenkel set theory
Transitive set
Ordinal number
Cardinal number
Set cardinality
Singleton set
Set of singletons
Singleton map
Definition D4493
Canonical singleton map
Formulation 1
Let $X$ be a D11: Set.
The canonical singleton map on $X$ is the D18: Map \begin{equation} X \to \left\{ \{ z \} : z \in X \right\}, \quad x \mapsto \{ x \} \end{equation}