Metamath Proof Explorer


Theorem cmnmnd

Description: A commutative monoid is a monoid. (Contributed by Mario Carneiro, 6-Jan-2015)

Ref Expression
Assertion cmnmnd ( 𝐺 ∈ CMnd → 𝐺 ∈ Mnd )

Proof

Step Hyp Ref Expression
1 eqid ( Base ‘ 𝐺 ) = ( Base ‘ 𝐺 )
2 eqid ( +g𝐺 ) = ( +g𝐺 )
3 1 2 iscmn ( 𝐺 ∈ CMnd ↔ ( 𝐺 ∈ Mnd ∧ ∀ 𝑥 ∈ ( Base ‘ 𝐺 ) ∀ 𝑦 ∈ ( Base ‘ 𝐺 ) ( 𝑥 ( +g𝐺 ) 𝑦 ) = ( 𝑦 ( +g𝐺 ) 𝑥 ) ) )
4 3 simplbi ( 𝐺 ∈ CMnd → 𝐺 ∈ Mnd )