ThmDex – An index of mathematical definitions, results, and conjectures.
▼ Set of symbols
▼ Alphabet
▼ Deduction system
▼ Theory
▼ Zermelo-Fraenkel set theory
▼ Set
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▼ Ordinal number
▼ Cardinal number
▼ Set cardinality
▼ Singleton set
▼ Duoton set
Definition D5042
Trioton set
Formulation 0
A D11: Set $X$ is a trioton set if and only if \begin{equation} |X| = 3 \end{equation}