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 ) |
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 ) |