Semigroups generated by certain operators on varieties of completely regular semigroups.
Mario Petrich and Norman R. Reilly
Pacific J. Math., Volume 132, Number 1 (1988), 151-175.
First available in Project Euclid: 8 December 2004
Permanent link to this document
Mathematical Reviews number (MathSciNet)
Zentralblatt MATH identifier
Primary: 20M07: Varieties and pseudovarieties of semigroups
Petrich, Mario; Reilly, Norman R. Semigroups generated by certain operators on varieties of completely regular semigroups.
Pacific J. Math. 132 (1988), no. 1, 151--175. https://projecteuclid.org/euclid.pjm/1102689799
-  Evaluation at the trivial variety. The diagram below presents a few varieties obtained by repeated application of the operators C,L? K, T,T and Tr to the trivial variety y . In order to save writing S' in the expressions of the form 3~C,3"T,3CTr, etc., we have written only C, ,Cr, etc. For example, the vertex labelled &= C = T stands for the variety of groups; this variety can also be described as 2C or 3T. The following legend is used to denote the classes induced by these operators:
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