Congruence properties of distributive double -algebras
Congruence schemes and their applications
Using congruence schemes we formulate new characterizations of congruence distributive, arithmetical and majority algebras. We prove new properties of the tolerance lattice and of the lattice of compatible reflexive relations of a majority algebra and generalize earlier results of H.-J. Bandelt, G. Cz'{e}dli and the present authors. Algebras whose congruence lattices satisfy certain 0-conditions are also studied.
Congruences of pseudocomplemented algebras
Congruences on pseudocomplemented semilattices
It is known that congruence lattices of pseudocomplemented semilattices are pseudocomplemented [4]. Many interesting properties of congruences on pseudocomplemented semilattices were described by Sankappanavar in [4], [5], [6]. Except for other results he described congruence distributive pseudocomplemented semilattices [6] and he characterized pseudocomplemented semilattices whose congruence lattices are Stone, i.e. belong to the variety B₁ [5]. In this paper we give a partial solution to a more...
Distributive lattices whose congruence lattice is Stone.
Double -algebras with Stone congruence lattices
Dualities for Stone algebras, double Stone algebras, and relative Stone algebras
Endomorphism semigroups of Brouwerian semilattices.
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...
Finitely generated almost universal varieties of -lattices
A concrete category is (algebraically) universal if any category of algebras has a full embedding into , and is almost universal if there is a class of -objects such that all non-constant homomorphisms between them form a universal category. The main result of this paper fully characterizes the finitely generated varieties of -lattices which are almost universal.
Finitely generated universal varieties of distributive double -algebras
Finite-to-finite universal varieties of distributive double -algebras
Flexible niveloids
Frame tolerances are directly decomposable
Free almost-p-lattices
Generalizations of Boolean algebras. An attribute exploration
Indexed annihilators in lattices
The concept of annihilator in lattice was introduced by M. Mandelker. Although annihilators have some properties common with ideals, the set of all annihilators in need not be a lattice. We give the concept of indexed annihilator which generalizes it and we show the basic properties of the lattice of indexed annihilators. Moreover, distributive and modular lattices can be characterized by using of indexed annihilators.
Modal Pseudocomplemented De Morgan Algebras
Modal pseudocomplemented De Morgan algebras (or -algebras for short) are investigated in this paper. This new equational class of algebras was introduced by A. V. Figallo and P. Landini ([Figallo, A. V., Landini, P.: Notes on -valued modal algebras Preprints del Instituto de Ciencias Básicas, Univ. Nac. de San Juan 1 (1990), 28–37.]) and they constitute a proper subvariety of the variety of all pseudocomplemented De Morgan algebras satisfying . Firstly, a topological duality for these algebras...
Notes on lattices of frame tolerances
On A Random Function Defined On A Pseudo Boolean Algebra