Retractive nil-extensions of regular semigroups, I
Stojan Bogdanović, Miroslav Ćirić · Proceedings of the Japan Academy Series A Mathematical Sciences · 1992
As retract extensions can be more easily constructed than many other kinds of extensions, it is of interest to know whether a given extension is a retract extension.The purpose of this paper is to give some criterions for retractive nil-extensions of semigroups, especially for the very important class of regular semigroups.