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 × 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 ∈ 𝐵 , 𝑦 ∈ 𝐵 ↦ ( 𝑥 ( Hom ‘ 𝐶 ) 𝑦 ) )
5 ovex ⊢ ( 𝑥 ( Hom ‘ 𝐶 ) 𝑦 ) ∈ V
6 4 5 fnmpoi ⊢ 𝐹 Fn ( 𝐵 × 𝐵 )