Semigroups generated by certain operators on varieties of completely regular semigroups
Mario Petrich, Norman R. Reilly · Pacific Journal of Mathematics · 1988
The operators C,K,L,T,T ( and T r on the lattice Se(^0t) of varieties of completely regular semigroups have played an important role in recent studies of S^(^9t\Although each of these operators is idempotent, when applied in various combinations to the trivial variety they yield varieties for which the only upper bound is ^^.The semigroups generated by various subsets of (C, K, L, T, T r , T { ) are determined here in terms of generators and relations.