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 : A 1-1 onto ran F F Fn A Fun F -1

Proof

Step Hyp Ref Expression
1 dff1o2 F : A 1-1 onto ran F F Fn A Fun F -1 ran F = ran F
2 eqid ran F = ran F
3 df-3an F Fn A Fun F -1 ran F = ran F F Fn A Fun F -1 ran F = ran F
4 2 3 mpbiran2 F Fn A Fun F -1 ran F = ran F F Fn A Fun F -1
5 1 4 bitri F : A 1-1 onto ran F F Fn A Fun F -1