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Green’s 𝒟 -relation for the multiplicative reduct of an idempotent semiring

Francis J. Pastijn, Xian Zhong Zhao (2000)

Archivum Mathematicum

The idempotent semirings for which Green’s 𝒟 -relation on the multiplicative reduct is a congruence relation form a subvariety of the variety of all idempotent semirings. This variety contains the variety consisting of all the idempotent semirings which do not contain a two-element monobisemilattice as a subsemiring. Various characterizations will be given for the idempotent semirings for which the 𝒟 -relation on the multiplicative reduct is the least lattice congruence.

Green's relations and their generalizations on semigroups

Kar-Ping Shum, Lan Du, Yuqi Guo (2010)

Discussiones Mathematicae - General Algebra and Applications

Green's relations and their generalizations on semigroups are useful in studying regular semigroups and their generalizations. In this paper, we first give a brief survey of this topic. We then give some examples to illustrate some special properties of generalized Green's relations which are related to completely regular semigroups and abundant semigroups.

Group conjugation has non-trivial LD-identities

Aleš Drápal, Tomáš Kepka, Michal Musílek (1994)

Commentationes Mathematicae Universitatis Carolinae

We show that group conjugation generates a proper subvariety of left distributive idempotent groupoids. This subvariety coincides with the variety generated by all cancellative left distributive groupoids.

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