Using a construction theorem of cryptogroups and congruence methods, we determine an 18-element lattice, generated by {NOBG, ROBG, OBG, NBA, RBA, BA}, of subvarieties of completely regular semigroups.
In this paper, we introduce the concept of VT-congruence triples on a regular semigroup S and show how such triples can be constructed by nsing the equivalences on S/L, S/R and the special congruences on S. Also, such...In this paper, we introduce the concept of VT-congruence triples on a regular semigroup S and show how such triples can be constructed by nsing the equivalences on S/L, S/R and the special congruences on S. Also, such congruence triples are characterized so that an associated congruence can be uniquely determined by a given congruence triple. Moreover, we also consider the VH-congruence pairs on an orthocryptogroup.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 10871161)the Research Foundations for Doctor Programme of Southwest University (Grant Nos. SWNUB2005020,SWNUB2008001)
文摘Using a construction theorem of cryptogroups and congruence methods, we determine an 18-element lattice, generated by {NOBG, ROBG, OBG, NBA, RBA, BA}, of subvarieties of completely regular semigroups.
基金Supported by National Natural Science Foundation of China （Grant No. 10571061）
文摘In this paper, we introduce the concept of VT-congruence triples on a regular semigroup S and show how such triples can be constructed by nsing the equivalences on S/L, S/R and the special congruences on S. Also, such congruence triples are characterized so that an associated congruence can be uniquely determined by a given congruence triple. Moreover, we also consider the VH-congruence pairs on an orthocryptogroup.
