▾ Set of symbols
▾ Alphabet
▾ Deduction system
▾ Theory
▾ Zermelo-Fraenkel set theory
▾ Set
▾ Binary cartesian set product
▾ Binary relation
▾ Empty binary relation
Canonical empty binary relation
Formulation 0
A D4: Binary relation $(X \times Y, R)$ is a canonical empty binary relation if and only if
(1) $R = \emptyset$ D857: Empty binary relation
(2) $X \times Y = \emptyset$