The sixtieth birthday of Professor Bedřich Pondělíček
Endomorphism monoids of bands.
Fast diagnosis of some semigroup properties of automata
On one NP-complete problem
Weak alg-universality and -universality of semigroup quasivarieties
In an earlier paper, the authors showed that standard semigroups , and play an important role in the classification of weaker versions of alg-universality of semigroup varieties. This paper shows that quasivarieties generated by and are neither relatively alg-universal nor -universal, while there do exist finite semigroups and generating the same semigroup variety as and respectively and the quasivarieties generated by and/or are quasivar-relatively -alg-universal and -universal...
On universality of semigroup varieties
A category is called -determined if every set of non-isomorphic -objects such that their endomorphism monoids are isomorphic has a cardinality less than . A quasivariety is called -universal if the lattice of all subquasivarieties of any quasivariety of finite type is a homomorphic image of a sublattice of the lattice of all subquasivarieties of . We say that a variety is var-relatively alg-universal if there exists a proper subvariety of such that homomorphisms of whose image does...
Simplicity of algebras requires to investigate almost all operations
Transformations determining uniquely a monoid
Transformations determining uniquely a monoid. II.
Transformations determining uniquely a monoid. III: Weak determinancy
Transformations determining uniquely a monoid. IV: Weak determinancy
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