Abbreviation: CanCMon
A \emph{cancellative commutative monoid} is a cancellative monoid M=⟨M,⋅,e⟩ such that
⋅ is commutative: x⋅y=y⋅x
Let M and N be cancellative commutative monoids. A morphism from M to N is a function h:MarrowN that is a homomorphism:
h(x⋅y)=h(x)⋅h(y), h(e)=e
Example 1: ⟨N,+,0⟩, the natural numbers, with addition and zero.
All commutative free monoids are cancellative.
All finite commutative (left or right) cancellative monoids are reducts of abelian groups.
f(1)=1f(2)=1f(3)=1f(4)=2f(5)=1f(6)=1f(7)=1