STANDARD REPRESENTATIONS OF ORTHODOX SEMIGROUPS

Abstract

Orthodox semigroups have been studied by many authors, in particular by Hall, Yamada and Petrich. In this paper, we give the standard representation of orthodox semigroups and investigate various e-varieties of orthodox semigroups which are determined by the standard representations.

Key Words:

• e-variety
• Orthodox semigroup
• Standard representation

2000 AMS Subject Classification:

• 20M10
• 20M19

ACKNOWLEDGMENTS

The authors would like to thank the referee for giving them some valuable suggestions in the presentation of this paper. This research is supported by an NSF grant of China (No. 10071068), a Youth Scientific Foundation grant of the Human Education Department (No. 02B024) and a UGC (HK) grant ^#2060187 (02/04).

Notes

^#Communicated by P. Higgins.