Metamath Proof Explorer

Theorem ffrn

Description: A function maps to its range. (Contributed by Glauco Siliprandi, 3-Mar-2021)

Ref Expression
Assertion ffrn 
|- ( F : A --> B -> F : A --> ran F )

Proof

Step Hyp Ref Expression
1 ffn 
 |-  ( F : A --> B -> F Fn A )
2 dffn3 
 |-  ( F Fn A <-> F : A --> ran F )
3 1 2 sylib 
 |-  ( F : A --> B -> F : A --> ran F )