Metamath Proof Explorer


Theorem bj-cmnssmnd

Description: Commutative monoids are monoids. (Contributed by BJ, 9-Jun-2019) (Proof modification is discouraged.)

Ref Expression
Assertion bj-cmnssmnd CMnd ⊆ Mnd

Proof

Step Hyp Ref Expression
1 df-cmn CMnd = { 𝑥 ∈ Mnd ∣ ∀ 𝑦 ∈ ( Base ‘ 𝑥 ) ∀ 𝑧 ∈ ( Base ‘ 𝑥 ) ( 𝑦 ( +g𝑥 ) 𝑧 ) = ( 𝑧 ( +g𝑥 ) 𝑦 ) }
2 1 ssrab3 CMnd ⊆ Mnd