Abundant semigroups with weakly simplistic RGQA transversals


Pei Wang, Xiangjun Kong




As the real common generalisations of both orthodox transversals and adequate transversals in abundant semigroups, the concept of refined generalised quasi-adequate transversals, briefly, RGQA transversals was introduced by Kong and Wang. In this paper, for the RGQA transversal, the necessary and sufficient condition for the sets I and Λ to be bands is investigated. It is demonstrated that the sets I and Λ are both bands if and only if the RGQA transversal is weakly simplistic. Moreover, the RGQA transversal S o being weakly simplistic is different from S o being a quasi-ideal nor the abundant semigroup S satisfying the regularity condition. Finally, by means of a quasi-adequate semigroup and a band, the structure theorem for an abundant semigroup with a weakly simplistic RGQA transversal is established.