This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.

Metamath Proof Explorer

Theorem ffun

Description: A mapping is a function. (Contributed by NM, 3-Aug-1994)

Ref Expression
Assertion ffun 
|- ( F : A --> B -> Fun F )

Proof

Step Hyp Ref Expression
1 ffn 
 |-  ( F : A --> B -> F Fn A )
2 fnfun 
 |-  ( F Fn A -> Fun F )
3 1 2 syl 
 |-  ( F : A --> B -> Fun F )