Set of symbols
Alphabet
Deduction system
Theory
Zermelo-Fraenkel set theory
Set
Transitive set
Ordinal number
Class of ordinal numbers
Formulation 0
The class of ordinal numbers is the D684: Class \begin{equation} \mathsf{Ord} : = \{ \alpha \mid \alpha \text{ is an ordinal number} \} \end{equation}
Also known as
Class of ordinals
Child definitions
» D1944: Strict ordinal number ordering relation