Metamath Proof Explorer


Theorem f1orn

Description: A one-to-one function maps onto its range. (Contributed by NM, 13-Aug-2004)

Ref Expression
Assertion f1orn F:A1-1 ontoranFFFnAFunF-1

Proof

Step Hyp Ref Expression
1 dff1o2 F:A1-1 ontoranFFFnAFunF-1ranF=ranF
2 eqid ranF=ranF
3 df-3an FFnAFunF-1ranF=ranFFFnAFunF-1ranF=ranF
4 2 3 mpbiran2 FFnAFunF-1ranF=ranFFFnAFunF-1
5 1 4 bitri F:A1-1 ontoranFFFnAFunF-1