Commutative semigroups whose lattice of tolerances is Boolean
Compact Boolean algebras
Compact connected semilattices without the fixed point property.
Compact partially ordered sets and compactification of partially ordered sets
Compact pospaces
Posets with property DINT which are compact pospaces with respect to the interval topologies are characterized.
Compactifications of partially ordered sets
Compactness properties of weighted summation operators on trees-the critical case
The aim of this paper is to provide upper bounds for the entropy numbers of summation operators on trees in a critical case. In a recent paper [Studia Math. 202 (2011)] we elaborated a framework of weighted summation operators on general trees where we related the entropy of the operator to those of the underlying tree equipped with an appropriate metric. However, the results were left incomplete in a critical case of the entropy behavior, because this case requires much more involved techniques....
Compactness properties of weighted summation operators on trees
We investigate compactness properties of weighted summation operators as mappings from ℓ₁(T) into for some q ∈ (1,∞). Those operators are defined by , t ∈ T, where T is a tree with partial order ⪯. Here α and σ are given weights on T. We introduce a metric d on T such that compactness properties of (T,d) imply two-sided estimates for , the (dyadic) entropy numbers of . The results are applied to concrete trees, e.g. moderately increasing, biased or binary trees and to weights with α(t)σ(t)...
Companion -algebras
Comparing sets of the Baire space by means of general recursive operators
Comparison of subset systems
Compatibility and central elements in pseudo-effect algebras
An equivalent definition of compatibility in pseudo-effect algebras is given, and its relationships with central elements are investigated. Furthermore, pseudo-MV-algebras are characterized among pseudo-effect algebras by means of compatibility.
Compatibility and partial compatibility in quantum logics
Compatibility in orthomodular posets
Compatibility problem in quasi-orthocomplemented posets
Compatible elements in partly ordered groups.
Compatible partial orderings in Boolean algebras
Complemented ordered sets
We introduce the concept of complementary elements in ordered sets. If an ordered set is a lattice, this concept coincides with that for lattices. The connections between distributivity and the uniqueness of complements are shown and it is also shown that modular complemented ordered sets represents “geometries” which are more general than projective planes.
Complemented tolerances on lattices
Complements in modular and semimodular lattices.