On a problem of Kertesz and Stern
On a problem of Pastijn and Petrich.
On a question of K. Leeb
On a Representation of Lattices by Congruence Relations
On a sum of observables in a logic
On a theorem of Cantor-Bernstein type for algebras
Freytes proved a theorem of Cantor-Bernstein type for algbras; he applied certain sequences of central elements of bounded lattices. The aim of the present paper is to extend the mentioned result to the case when the lattices under consideration need not be bounded; instead of sequences of central elements we deal with sequences of internal direct factors of lattices.
On a weak Freudenthal spectral theorem
Let be an Archimedean Riesz space and its Boolean algebra of all band projections, and put and , . is said to have Weak Freudenthal Property () provided that for every the lattice is order dense in the principal band . This notion is compared with strong and weak forms of Freudenthal spectral theorem in Archimedean Riesz spaces, studied by Veksler and Lavrič, respectively. is equivalent to -denseness of in for every , and every Riesz space with sufficiently many projections...
On algebraic closures of compact elements
On algebra-lattices
On Atomistic Algebraic Lattices with Covering Property
On atomistic lattices.
On atoms in lattices of primitive classes
On atoms in tolerance lattices of distributive lattices
On automorphism groups of planar lattices
The structure of automorphisms of planar lattices is analyzed.
On binary coproducts of frames
The structure of binary coproducts in the category of frames is analyzed, and the results are then applied widely in the study of compactness, local compactness (continuous frames), separatedness, pushouts and closed frame homomorphisms.
On bounding congruences in some algebras having the lattice structure
On Butler -groups decomposing over two base elements
A -group is a sum of a finite number of torsionfree Abelian groups of rank , subject to two independent linear relations. We complete here the study of direct decompositions over two base elements, determining the cases where the relations play an essential role.
On central atoms of Archimedean atomic lattice effect algebras
If element of a lattice effect algebra is central, then the interval is a lattice effect algebra with the new top element and with inherited partial binary operation . It is a known fact that if the set of central elements of is an atomic Boolean algebra and the supremum of all atoms of in equals to the top element of , then is isomorphic to a direct product of irreducible effect algebras ([16]). In [10] Paseka and Riečanová published as open problem whether is a bifull sublattice...
On central relations of complete lattices
On closed lattices