▾ Set of symbols
▾ Alphabet
▾ Deduction system
▾ Theory
▾ Zermelo-Fraenkel set theory
▾ Set
▾ Binary cartesian set product
▾ Binary relation
▾ Binary endorelation
▾ Preordering relation
▾ Partial ordering relation
▾ Ordering relation
▾ Ordered set
▾ Dedekind cut
▾ Set of real numbers
▾ Real number
▾ Cantor number
Standard Cantor number
Formulation 1
A D993: Real number $x \in \mathbb{R}$ is a standard Cantor number if and only if \begin{equation} \exists \, a_1, a_2, a_3, \ldots \in \{ 0, 2 \} : x = \sum_{n \in \{ 1, 2, 3, \ldots \}} \frac{a_n}{3^n} \end{equation}
Child definitions
» D3731: Standard Cantor set