Definition:Affine Monoid

Definition
An affine monoid is a monoid that is:
 * finitely generated

and:
 * isomorphic to a submonoid of a free abelian group $\Z^d$, for some $d \in \Z_{\ge 0}$.

Also see

 * Affine Monoid is Cancellative
 * Affine Monoid is Torsion-Free
 * Affine Monoid is Commutative