IMCS/Publications/QRS/Issues/QRS v.20, n.2 (28), 2012/

Clifford congruences on an idempotent-surjective R-semigroup

Authors: R. S. Gigon


We describe the least Clifford congruence on an idempotent-surjective R-semigroup, and so we generalize the result of LaTorre (1983). In addition, a characterization of all Clifford congruences on such a semigroup (in particular, on a structurally regular semigroup) is given. Moreover, using some earlier result, we give a description of all USG-congruences on an idempotent-surjective semigroup, and so we generalize the result of Howie and Lallement for regular semigroups (1966). Finally, in Section 4 we study the subdirect products of an E-unitary semigroup and a Clifford semigroup.


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