Metamath Proof Explorer


Theorem fisuppfi

Description: A function on a finite set is finitely supported. (Contributed by Mario Carneiro, 20-Jun-2015)

Ref Expression
Hypotheses fisuppfi.1
|- ( ph -> A e. Fin )
fisuppfi.2
|- ( ph -> F : A --> B )
Assertion fisuppfi
|- ( ph -> ( `' F " C ) e. Fin )

Proof

Step Hyp Ref Expression
1 fisuppfi.1
 |-  ( ph -> A e. Fin )
2 fisuppfi.2
 |-  ( ph -> F : A --> B )
3 cnvimass
 |-  ( `' F " C ) C_ dom F
4 3 2 fssdm
 |-  ( ph -> ( `' F " C ) C_ A )
5 1 4 ssfid
 |-  ( ph -> ( `' F " C ) e. Fin )