Semilattices of Stratified Semigroups

Abstract

In 1995 Grillet introduced the concept of a stratified semigroup as a kind of generalisation of finite nilsemigroups. We extend these ideas here by allowing a more general Base and describe them in terms of extensions of semigroups by stratified semigroups. We consider semillatices of certain types of group-bound semigroups and also semillatices of Clifford semigroups and show how to describe them as semilattices of these stratified extensions and provide a number of interesting examples.