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 D4468
Empty metric space
Formulation 0
An D548: Ordered pair $M = (X, d)$ is an empty metric space if and only if
(1) $X = \emptyset$ (D13: Empty set)
(2) $d$ is an D219: Empty map