A System of Bi-Identities for Locally Inverse Semigroups
K. Auinger · Proceedings of the American Mathematical Society · 1995
A class of regular semigroups closed under taking direct products, regular subsemigroups, and homomorphic images is an existence-variety (or e-variety) of regular semigroups. Each e-variety of locally inverse semigroups can be characterized by a set of bi-identities. These are identities of terms of type $\langle 2,2\rangle$ in two sorts of variables X and $X’$. In this paper we obtain a basis of bi-identities for the e-variety of locally inverse semigroups and for certain sub-e-varieties.