Metamath Proof Explorer


Theorem homffn

Description: The functionalized Hom-set operation is a function. (Contributed by Mario Carneiro, 4-Jan-2017)

Ref Expression
Hypotheses homffn.f
|- F = ( Homf ` C )
homffn.b
|- B = ( Base ` C )
Assertion homffn
|- F Fn ( B X. B )

Proof

Step Hyp Ref Expression
1 homffn.f
 |-  F = ( Homf ` C )
2 homffn.b
 |-  B = ( Base ` C )
3 eqid
 |-  ( Hom ` C ) = ( Hom ` C )
4 1 2 3 homffval
 |-  F = ( x e. B , y e. B |-> ( x ( Hom ` C ) y ) )
5 ovex
 |-  ( x ( Hom ` C ) y ) e. _V
6 4 5 fnmpoi
 |-  F Fn ( B X. B )