Quasi-adequate semigroups
Abdulsalam El-Qallali, John Fountain · Proceedings of the Royal Society of Edinburgh Section A Mathematics · 1981
Synopsis The investigation of general quasi-adequate semigroups is initiated. These are semigroups which are abundant and in which the idempotents form a subsemigroup. For such a semigroup S we study the minimum good congruence γ such that S/γ is adequate. Results on γ together with results from a previous paper of the authors are used to obtain a structure theorem for a class of quasi-adequate semigroups.