Metamath Proof Explorer


Theorem fthi

Description: The morphism map of a faithful functor is an injection. (Contributed by Mario Carneiro, 27-Jan-2017)

Ref Expression
Hypotheses isfth.b B = Base C
isfth.h H = Hom C
isfth.j J = Hom D
fthf1.f φ F C Faith D G
fthf1.x φ X B
fthf1.y φ Y B
fthi.r φ R X H Y
fthi.s φ S X H Y
Assertion fthi φ X G Y R = X G Y S R = S

Proof

Step Hyp Ref Expression
1 isfth.b B = Base C
2 isfth.h H = Hom C
3 isfth.j J = Hom D
4 fthf1.f φ F C Faith D G
5 fthf1.x φ X B
6 fthf1.y φ Y B
7 fthi.r φ R X H Y
8 fthi.s φ S X H Y
9 1 2 3 4 5 6 fthf1 φ X G Y : X H Y 1-1 F X J F Y
10 f1fveq X G Y : X H Y 1-1 F X J F Y R X H Y S X H Y X G Y R = X G Y S R = S
11 9 7 8 10 syl12anc φ X G Y R = X G Y S R = S