摘要
A semigroup (S, .) is called right (left) quasiresiduated if for any a, b in S there exists x in S such that ax≤s b (xa≤s b) with respect to the natural partial order ≤s of S. This concept has its origin in the theory of residuated semigroups, but can also be seen as a generalization of the right (left) simplicity of semigroups. It is first studied for totally-, resp., trivially-ordered semigroups, and then for semigroups with idempotents. In particular, the cases when (S≤s) is directed downwards and when S contains a zero (with respect to a more restrictive definition) are dealt with. Throughout, examples are given; in total, 30 classes of (often well-known) semigroups of this kind are specified.
A semigroup (S, .) is called right (left) quasiresiduated if for any a, b in S there exists x in S such that ax≤s b (xa≤s b) with respect to the natural partial order ≤s of S. This concept has its origin in the theory of residuated semigroups, but can also be seen as a generalization of the right (left) simplicity of semigroups. It is first studied for totally-, resp., trivially-ordered semigroups, and then for semigroups with idempotents. In particular, the cases when (S≤s) is directed downwards and when S contains a zero (with respect to a more restrictive definition) are dealt with. Throughout, examples are given; in total, 30 classes of (often well-known) semigroups of this kind are specified.
作者
Heinz Mitsch
Heinz Mitsch(Fakul t f r Mathematik, Universit t Wien Oskax Morgenstern Platz 1, A-1090 Wien, Austria)