Metamath Proof Explorer


Theorem mhmf

Description: A monoid homomorphism is a function. (Contributed by Mario Carneiro, 7-Mar-2015)

Ref Expression
Hypotheses mhmf.b B = Base S
mhmf.c C = Base T
Assertion mhmf F S MndHom T F : B C

Proof

Step Hyp Ref Expression
1 mhmf.b B = Base S
2 mhmf.c C = Base T
3 eqid + S = + S
4 eqid + T = + T
5 eqid 0 S = 0 S
6 eqid 0 T = 0 T
7 1 2 3 4 5 6 ismhm F S MndHom T S Mnd T Mnd F : B C x B y B F x + S y = F x + T F y F 0 S = 0 T
8 7 simprbi F S MndHom T F : B C x B y B F x + S y = F x + T F y F 0 S = 0 T
9 8 simp1d F S MndHom T F : B C