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  |