Metamath Proof Explorer


Theorem rhmmhm

Description: A ring homomorphism is a homomorphism of multiplicative monoids. (Contributed by Stefan O'Rear, 7-Mar-2015)

Ref Expression
Hypotheses isrhm.m ⊢ M = mulGrp R
isrhm.n ⊢ N = mulGrp S
Assertion rhmmhm ⊢ F ∈ R RingHom S → F ∈ M MndHom N

Proof

Step Hyp Ref Expression
1 isrhm.m ⊢ M = mulGrp R
2 isrhm.n ⊢ N = mulGrp S
3 1 2 isrhm ⊢ F ∈ R RingHom S ↔ R ∈ Ring ∧ S ∈ Ring ∧ F ∈ R GrpHom S ∧ F ∈ M MndHom N
4 3 simprbi ⊢ F ∈ R RingHom S → F ∈ R GrpHom S ∧ F ∈ M MndHom N
5 4 simprd ⊢ F ∈ R RingHom S → F ∈ M MndHom N