E-SOLID E-VARIETIES OF REGULAR SEMIGROUPS WHICH ARE BIEQUATIONAL
Raymond Broeksteeg · International Journal of Algebra and Computation · 1996
We extend the notion of biidentity from bivarieties of orthodox semigroups to e-varieties of regular semigroups. We show that an E-solid e-variety ε may be described in terms of biidentities (within the e-variety of all regular semigroups) if and only if there is an integer n≥2 such that for each pair e, f of idempotents of each member of ε, we have that (ef)n=ef.