Atomicity of tolerance lattices of commutative semigroups
In the present paper, we will show that the set of minimal elements of a full affine semigroup contains a free basis of the group generated by in . This will be applied to the study of the group for a semilocal ring .
We describe algorithms for computing the nilradical and the zero-divisors of a finitely generated commutative -monoid. These algorithms will be used for deciding if a given ideal of a finitely generated commutative -monoid is prime, radical or primary.
Every commutative nil-semigroup of index 2 can be imbedded into such a semigroup without irreducible elements.