Displaying similar documents to “On modular elements of the lattice of semigroup varieties”

Presolid varieties of n-semigroups

Avapa Chantasartrassmee, Jörg Koppitz (2005)

Discussiones Mathematicae - General Algebra and Applications

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he class of all M-solid varieties of a given type t forms a complete sublattice of the lattice ℒ(τ) of all varieties of algebrasof type t. This gives a tool for a better description of the lattice ℒ(τ) by characterization of complete sublattices. In particular, this was done for varieties of semigroups by L. Polák ([10]) as well as by Denecke and Koppitz ([4], [5]). Denecke and Hounnon characterized M-solid varieties of semirings ([3]) and M-solid varieties of groups were characterized...

On permutability in semigroup varieties

Bedřich Pondělíček (1991)

Mathematica Bohemica

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The paper contains characterizations of semigroup varieties whose semigroups with one generator (two generators) are permutable. Here all varieties of regular * -semigroups are described in which each semigroup with two generators is permutable.