Metamath Proof Explorer


Theorem rimgim

Description: An isomorphism of rings is an isomorphism of their additive groups. (Contributed by AV, 24-Dec-2019)

Ref Expression
Assertion rimgim ⊢ F ∈ R RingIso S → F ∈ R GrpIso S

Proof

Step Hyp Ref Expression
1 rimrhm ⊢ F ∈ R RingIso S → F ∈ R RingHom S
2 rhmghm ⊢ F ∈ R RingHom S → F ∈ R GrpHom S
3 1 2 syl ⊢ F ∈ R RingIso S → F ∈ R GrpHom S
4 eqid ⊢ Base R = Base R
5 eqid ⊢ Base S = Base S
6 4 5 rimf1o ⊢ F ∈ R RingIso S → F : Base R ⟶ 1-1 onto Base S
7 4 5 isgim ⊢ F ∈ R GrpIso S ↔ F ∈ R GrpHom S ∧ F : Base R ⟶ 1-1 onto Base S
8 3 6 7 sylanbrc ⊢ F ∈ R RingIso S → F ∈ R GrpIso S