ThmDex – An index of mathematical definitions, results, and conjectures.
Set of symbols
Alphabet
Deduction system
Theory
Zermelo-Fraenkel set theory
Set
Collection of sets
Set union
Successor set
Inductive set
Set of inductive sets
Set of natural numbers
Set of integers
Set of rational numbers
Definition D994
Rational number
Formulation 0
Let $\mathbb{Q}$ be the D368: Set of rational numbers.
Then $q$ is a rational number if and only if \begin{equation} q \in \mathbb{Q} \end{equation}
Children
P-adic rational number