Metamath Proof Explorer


Definition df-mndo

Description: A monoid is a semigroup with an identity element. (Contributed by FL, 2-Nov-2009) (New usage is discouraged.)

Ref Expression
Assertion df-mndo MndOp = SemiGrp ExId

Detailed syntax breakdown

Step Hyp Ref Expression
0 cmndo class MndOp
1 csem class SemiGrp
2 cexid class ExId
3 1 2 cin class SemiGrp ExId
4 0 3 wceq wff MndOp = SemiGrp ExId