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 MndOp
1 csem SemiGrp
2 cexid ExId
3 1 2 cin ( SemiGrp ∩ ExId )
4 0 3 wceq MndOp = ( SemiGrp ∩ ExId )