ThmDex – An index of mathematical definitions, results, and conjectures.
▼ Set of symbols
▼ Alphabet
▼ Deduction system
▼ Theory
▼ Zermelo-Fraenkel set theory
▼ Set
▼ Transitive set
▼ Ordinal number
▼ Cardinal number
▼ Set cardinality
Definition D135
Singleton set
Formulation 0
A D11: Set $X$ is a singleton set if and only if \begin{equation} |X| = 1 \end{equation}
Also known as
Enton set
Children
▶ D3835: Duoton set
▶ D4316: Set of singletons