Metamath Proof Explorer


Theorem f1fun

Description: A one-to-one mapping is a function. (Contributed by NM, 8-Mar-2014)

Ref Expression
Assertion f1fun F:A1-1BFunF

Proof

Step Hyp Ref Expression
1 f1fn F:A1-1BFFnA
2 fnfun FFnAFunF
3 1 2 syl F:A1-1BFunF