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Some remarks on modularity of the congruence lattice of regular ω-semigroups

Part of: Semigroups

Published online by Cambridge University Press:  09 April 2009

C. Bonzini
Affiliation:
Universitá, Via Saldini 50, 20133 Milano, Italia, email: [email protected]
A. Cherubini
Affiliation:
Politecnicó, Piazza L. ad Vinci 32, 20133 Milano, Italia, email: [email protected]
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Abstract

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In this paper conditions of M-symmetry, strong, semimodularity and θ-modularity for the congruence lattice L (S) of a regular ω-semigroup S are studied. They are proved to be equivalent to modularity. Moreover it is proved that the kernel relation is a congruence on L(S) if and only if L(S) is modular, generalizing an analogous result stated by Petrich for bisimple ω-semigroups.

MSC classification

Type
Research Article
Copyright
Copyright © Australian Mathematical Society 1995

References

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