Metamath Proof Explorer


Theorem f1of

Description: A one-to-one onto mapping is a mapping. (Contributed by NM, 12-Dec-2003)

Ref Expression
Assertion f1of F:A1-1 ontoBF:AB

Proof

Step Hyp Ref Expression
1 f1of1 F:A1-1 ontoBF:A1-1B
2 f1f F:A1-1BF:AB
3 1 2 syl F:A1-1 ontoBF:AB