ThmDex – An index of mathematical definitions, results, and conjectures.
Formulation F10725 on R4628: Map to empty set is a surjection
F10725
Formulation 0
Let $\emptyset$ be the D13: Empty set such that
(i) $f : X \to \emptyset$ is a D18: Map
Then $f$ is a D466: Surjective map.