ThmDex – An index of mathematical definitions, results, and conjectures.
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Deduction system
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Zermelo-Fraenkel set theory
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Singleton set
Definition D4316
Set of singletons
Formulation 0
Let $X$ be a D11: Set.
The set of singletons in $X$ is the D11: Set \begin{equation} \{ \{ x \} : x \in X \} \end{equation}
Children
D5359: Singleton map