On pushing out frames
On quasi-homomorphisms and compositions of automata
On quasitilted algebras which are one-point extensions of hereditary algebras
Quasitilted algebras have been introduced as a proper generalization of tilted algebras. In an earlier article we determined necessary conditions for one-point extensions of decomposable finite-dimensional hereditary algebras to be quasitilted and not tilted. In this article we study algebras satisfying these necessary conditions in order to investigate to what extent the conditions are sufficient.
On quasivarieties of partial algebras, their generation and their subquasivarieties. I
On quasivarieties of partial algebras, their generation and their subquasivarieties II
On -fuzzy Petri nets.
On Real Local-Global Principles.
On realization and boundability of concrete categories in which the morphisms are choiced by local conditions
On reflective subcategories of quasiabelian categories.
On reflexive subobject lattices and reflexive endomorphism algebras
In this paper we study the reflexive subobject lattices and reflexive endomorphism algebras in a concrete category. For the category Set of sets and mappings, a complete characterization for both reflexive subobject lattices and reflexive endomorphism algebras is obtained. Some partial results are also proved for the category of abelian groups.
On regular presheaves and regular semi-categories
On relative extension groups in the category of commutative diagrams.
On rich monoids
On rings whose flat modules form a Grothendieck category
On saturated classes of morphisms.
On selecting of morphisms among all mappings between underlying sets of objects in concrete categories and realisations of these
On several varieties of cacti and their relations.
On sifted colimits and generalized varieties.
On simply bireflective subcategories
On some adjunctions between the categories of adjunction-morphisms and monad-morphisms