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Varieties of completely regular semigroups

Part of: Semigroups

Published online by Cambridge University Press:  09 April 2009

Norman R. Reilly
Affiliation:
Deparment of Mathematics and Statistics, Simon Fraser UniversityBurnaby, B. C. V5A 1A6, Canada
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Abstract

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If CS(respectively, O) denotes the class of all completely simple semigroups (respectively, semigroups that are orthodox unions of groups) then CS(respectively, O) is a variety of algebras with respect to the operations of multiplication and inversion. The main result shows that the lattice of subvarieties of is a precisely determined subdirect product of the lattice of subvarieties of CSand the lattice of subvarieties of O. A basis of identities is obtained for any variety in terms of bases of identities for . Several operators on the lattice of subvarieties of are also introduced and studied.

Type
Research Article
Copyright
Copyright © Australian Mathematical Society 1985

References

[1]Birjukov, A. P., ‘Varieties of idempotent semigroups’, Algebra i Logika 9 (1970), 255273 (Russian)Google Scholar
[2]Fennemore, C. F., ‘All varieties of bands’, Math. Nachr. 4 (1971); I: 237–255; II: 253–262.Google Scholar
[3]Gerhard, J. A., ‘The lattice of equational classes of idempotent semigroups’, J. Algebra 15 (1970), 195224.CrossRefGoogle Scholar
[4]Gerhard, J. A., and Petrich, M., ‘All varieties of regular orthogroups’, manuscript.Google Scholar
[5]Hall, T. E., ‘On regular semigroups’, J. Algebra 24 (1973), 124.CrossRefGoogle Scholar
[6]Hall, T. E., and Jones, P. R., ‘On the lattice of varieties of bands of groups’, Pacific J. Math. 91 (1980) 327337.CrossRefGoogle Scholar
[7]Howie, J. M., An introduction to semigroup theory (Academic Press, London, 1976).Google Scholar
[8]Jones, P. R., ‘Completely simple semigroups: free products, free semigroups and varieties’, Proc. Roy. Soc. Edinburgh Sect. A 88 (1981), 293313.CrossRefGoogle Scholar
[9]Jones, P. R., ‘Varieties of completely regular semigroups’, J. Austral. Math. Soc. (Series A) 35 (1983), 227235.CrossRefGoogle Scholar
[10]Petrich, M., ‘Varieties of orthodox bands of groups’, Pacific J. Math. 58 (1975), 209217.CrossRefGoogle Scholar
[11]Petrich, M., ‘Certain varieties and quasivarieties of completely regular semigroups’, Canad. J. Math. 29, (1977), 11711197.CrossRefGoogle Scholar
[12]Petrich, M., ‘On the varieties of completely regular semigroups’, Semigroup Forum 25 (1982) 153169.CrossRefGoogle Scholar
[13]Petrich, M., and Reilly, N. R., ‘A network of congruences on an inverse sernigroup’, Trans. Amer. Math. Soc. 270 (1982), 309325.CrossRefGoogle Scholar
[14]Petrich, M. and Reilly, N. R., ‘Bands of groups with universal properties’, Monatshefte für Mathematik 94 (1982), 4567.CrossRefGoogle Scholar
[15]Petrich, M. and Reilly, N. R., ‘Varieties of groups and of completely simple semigroups’, Bull. Austral. Math. Soc. 23 (1981), 339359.CrossRefGoogle Scholar
[16]Petrich, M. and Reilly, N. R., ‘Near varieties of idempotent generated completely simple semigroups’, Algebra Universalis 16 (1983), 83104.CrossRefGoogle Scholar
[17]Petrich, M. and Reilly, N. R., ‘All varieties of central completely simple semigroups’, Trans. Amer. Math. Soc. 280 (1983), 623636.CrossRefGoogle Scholar
[18]Petrich, M. and Reilly, N. R., ‘Certain homomorphism of the lattice of varieties of completely simple semigroups’, J. Austral. Math. Soc. (to appear).Google Scholar
[19]Rasin, V. V., ‘On the lattice of varieties of completely simple semigroups’, Semi group Forum 17 (1979), 113122.CrossRefGoogle Scholar
[20]Rasin, V. V., ‘On the varieties of Cliffordian semigroups’, Semigroup Forum 23 (1981), 201220.CrossRefGoogle Scholar
[21]Wismath, S., ‘The lattice of varieties and pseudovarieties of band monoids’, Thesis, Simon Fraser University, 1983.Google Scholar
[22]Wismath, S., ‘The lattice of varieties and pseudovarieties of band monoids’. manuscript.Google Scholar