On existence varieties of orthodox semigroups
J. Doyle · Journal of the Australian Mathematical Society Series A Pure Mathematics and Statistics · 1995
Abstract An existence variety of regular semigroups is a class of regular semigroups which is closed under the operations of forming all homomorphic images, all regular subsemigroups and all direct products. In this paper we generalize results on varieties of inverse semigroups to existence varieties of orthodox semigroups.