Metamath Proof Explorer


Theorem dmnrngo

Description: Obsolete theorem, use idomringd instead. A domain is a ring. (Contributed by Jeff Madsen, 6-Jan-2011) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Assertion dmnrngo ⊢ R ∈ Dmn → R ∈ RingOps

Proof

Step Hyp Ref Expression
1 dmncrng ⊢ R ∈ Dmn → R ∈ CRingOps
2 crngorngo ⊢ R ∈ CRingOps → R ∈ RingOps
3 1 2 syl ⊢ R ∈ Dmn → R ∈ RingOps