Metamath Proof Explorer

Theorem ffun

Description: A mapping is a function. (Contributed by NM, 3-Aug-1994) (Proof shortened by Umit Teoman Dogan, 10-Jun-2026)

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

Proof

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