Article
Keywords:
semigroup; completely regular; variety; basis; local relation
Summary:
Completely regular semigroups equipped with the unary operation of inversion within their maximal subgroups form a variety, denoted by $\mathscr{CR}$. The lattice of subvarieties of $\,\mathscr{CR}$ is denoted by $\mathcal{L}(\mathscr{CR})$. For each variety in an $\bigcap$-subsemilattice $\Gamma$ of $\mathcal{L}(\mathscr{CR})$, we construct at least one basis of identities, and for some important varieties, several. We single out certain remarkable types of bases of general interest. As an application for the local relation $L$, we construct $\mathbf{L}$-classes of all varieties in $\Gamma$. Two figures illustrate the theory.
References:
[7] Petrich M.: Relations on some varieties of completely regular semigroups. manuscript.
[9] Petrich M., Reilly N. R.:
Operators related to idempotent generated and monoid completely regular semigroups. J. Austral. Math. Soc. Ser. A 49 (1990), no. 1, 1–23.
DOI 10.1017/S1446788700030202 |
MR 1054079
[10] Petrich M., Reilly N. R.:
Completely Regular Semigroups. Canadian Mathematical Society Series of Monographs and Advanced Texts, 23, A Wiley-Interscience Publication, John Wiley & Sons, New York, 1999.
MR 1684919