Affine monoid

In abstract algebra, a branch of mathematics, an affine monoid is a commutative monoid that is finitely generated, and is isomorphic to a submonoid of a free abelian group ℤ"d", "d" ≥ 0. Affine monoids are closely connected to convex polyhedra, and their associated algebras are of much use in the algebraic study of these geometric objects.
Affine monoids.
Group of differences.
Definition.
formula_30 defines the addition.
Normal affine monoids.
Definition.
is the integral closure of formula_8 in formula_14. If formula_51, then formula_8 is integrally closed