ThmDex – An index of mathematical definitions, results, and conjectures.
Set of symbols
Alphabet
Deduction system
Theory
Zermelo-Fraenkel set theory
Set
Binary cartesian set product
Binary relation
Map
Operation
N-operation
Binary operation
Basic binary operation
Unsigned basic binary operation
Semimetric
Metric
Metric space
Definition D1224
Set diameter
Formulation 0
Let $M = (X, d)$ be a D1107: Metric space such that
(i) $E \subseteq X$ is a D78: Subset of $X$
The diameter of $E$ in $M$ is the D1699: Basic number \begin{equation} \sup_{x, y \in E} d(x, y) \end{equation}