Metamath Proof Explorer


Theorem homa1

Description: The first component of an arrow is the ordered pair of domain and codomain. (Contributed by Mario Carneiro, 11-Jan-2017)

Ref Expression
Hypothesis homahom.h H = Hom a C
Assertion homa1 Z X H Y F Z = X Y

Proof

Step Hyp Ref Expression
1 homahom.h H = Hom a C
2 df-br Z X H Y F Z F X H Y
3 eqid Base C = Base C
4 1 homarcl Z F X H Y C Cat
5 eqid Hom C = Hom C
6 1 3 homarcl2 Z F X H Y X Base C Y Base C
7 6 simpld Z F X H Y X Base C
8 6 simprd Z F X H Y Y Base C
9 1 3 4 5 7 8 elhoma Z F X H Y Z X H Y F Z = X Y F X Hom C Y
10 2 9 sylbi Z X H Y F Z X H Y F Z = X Y F X Hom C Y
11 10 ibi Z X H Y F Z = X Y F X Hom C Y
12 11 simpld Z X H Y F Z = X Y