Turkish Journal of Mathematics
DOI
-
Abstract
In this paper we generalize the class of completely regular semigroups (unions of groups) to the class of local monoids, that is the class of all semigroups where the local subsemigroups \( aSa \) are local submonoids. The sublattice of this variety \( (\mathbf{L}(\caL(\cam)) \) covers another lattice isomorphic to the lattice of all bands \( ([x^2 = x]). \) Every bundvariety \( \cau \) has as image the variety \( \Phi - \cau, \) which is the class of all semigroups, where \( \Phi \) is a \( \cau \)-congruence \( (a \Phi b \Leftrightarrow aSa = bSb). \) It is shown how one can find the laws for \( \Phi - \cau \) for a given bandvariety \( \cau \). The laws for \( \Phi - \cab \) are given and it is shown that \( \Phi - \car\cab - \caL(\cag) \caL(\cav) := \{S : aSa \in \cav \forall a \in S\}). \)
First Page
145
Last Page
152
Recommended Citation
TIEFENBACH, A. (1998) "On Certain Varieties of Semigroups," Turkish Journal of Mathematics: Vol. 22: No. 2, Article 2. Available at: https://journals.tubitak.gov.tr/math/vol22/iss2/2
