Description: Commutative monoids are monoids. (Contributed by BJ, 9-Jun-2019) (Proof modification is discouraged.)
Ref | Expression | ||
---|---|---|---|
Assertion | bj-cmnssmnd | |- CMnd C_ Mnd |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | df-cmn | |- CMnd = { x e. Mnd | A. y e. ( Base ` x ) A. z e. ( Base ` x ) ( y ( +g ` x ) z ) = ( z ( +g ` x ) y ) } |
|
2 | 1 | ssrab3 | |- CMnd C_ Mnd |