Well-posed minimum problems for preorders
Well-quasi-ordering Aronszajn lines
We show that, assuming PFA, the class of all Aronszajn lines is well-quasi-ordered by embeddability.
When a partial Borel order is linearizable
When is a poset isomorphic to the poset of connected induced subgraphs of a graph?
Where the typical set partitions meet and join.
Which countable ordered sets have a dense linear extension?
Words avoiding a reflexive acyclic relation.
Wreath products of permutation classes.
Z-mappings and a classification theorem.
Zu Äquivalenz- und Ordnungsrelationen
-filters and -order-ideals in distributive quasicomplemented semilattices
We introduce some particular classes of filters and order-ideals in distributive semilattices, called -filters and -order-ideals, respectively. In particular, we study -filters and -order-ideals in distributive quasicomplemented semilattices. We also characterize the filters-congruence-cokernels in distributive quasicomplemented semilattices through -order-ideals.
-ideals in -distributive posets
The concept of -ideals in posets is introduced. Several properties of -ideals in -distributive posets are studied. Characterization of prime ideals to be -ideals in -distributive posets is obtained in terms of minimality of ideals. Further, it is proved that if a prime ideal of a -distributive poset is non-dense, then is an -ideal. Moreover, it is shown that the set of all -ideals of a poset with forms a complete lattice. A result analogous to separation theorem for finite -distributive...
-lattices
In this paper, we generalize the notion of supremum and infimum in a poset.
-допустимые семейства над линейными порядками.
σ-Entangled linear orders and narrowness of products of Boolean algebras
We investigate σ-entangled linear orders and narrowness of Boolean algebras. We show existence of σ-entangled linear orders in many cardinals, and we build Boolean algebras with neither large chains nor large pies. We study the behavior of these notions in ultraproducts.
Верхние полурешетки нумераций
Выпуклость в частично упорядоченном множестве
Вычисление эффективных операторов на машинах Тьюринга с ограниченным стиранием
Гомоморфизмы унарных алгебрь
Гомоморфное отображение между пространствами функций