Metamath Proof Explorer


Theorem ffrn

Description: A function maps to its range. (Contributed by Glauco Siliprandi, 3-Mar-2021)

Ref Expression
Assertion ffrn F:ABF:AranF

Proof

Step Hyp Ref Expression
1 ffn F:ABFFnA
2 dffn3 FFnAF:AranF
3 1 2 sylib F:ABF:AranF