On categories into which each concrete category can be embedded
On categories into which each concrete category can be embedded. II
Set functor. II: Contravariant case
Finite-to-finite universal varieties of distributive double -algebras
Representations in varieties of regular involution bands
Set functors
Each concrete category has a representation by paracompact topological spaces
Graphs with given subgraphs represent all categories
Graphs with given subgraphs represent all categories. II.
Large systems of independent objects in concrete categories. II
Large systems of independent objects in concrete categories. I
Endomorphism monoids of bands.
On a representation of semigroups by products of algebras and relations
Completions of concrete categories
Equimorphy in varieties of distributive double -algebras
Any finitely generated regular variety of distributive double -algebras is finitely determined, meaning that for some finite cardinal , any subclass of algebras with isomorphic endomorphism monoids has fewer than pairwise non-isomorphic members. This result follows from our structural characterization of those finitely generated almost regular varieties which are finitely determined. We conjecture that any finitely generated, finitely determined variety of distributive double -algebras...
A set functor which commutes with all homfunctors is a homfunctor
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...
Regular societies without short cycles
On number of covering arcs in orderings
What to embed into a Cartesian closed topological category (Preliminary communication)
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