Optimal natural dualities for some quasivarities of distributive double -algebras.
Order affine completeness of lattices with Boolean congruence lattices
This paper grew out from attempts to determine which modular lattices of finite height are locally order affine complete. A surprising discovery was that one can go quite far without assuming the modularity itself. The only thing which matters is that the congruence lattice is finite Boolean. The local order affine completeness problem of such lattices easily reduces to the case when is a subdirect product of two simple lattices and . Our main result claims that such a lattice is locally...
Orthocomplemented difference lattices with few generators
The algebraic theory of quantum logics overlaps in places with certain areas of cybernetics, notably with the field of artificial intelligence (see, e. g., [19, 20]). Recently an effort has been exercised to advance with logics that possess a symmetric difference ([13, 14]) - with so called orthocomplemented difference lattices (ODLs). This paper further contributes to this effort. In [13] the author constructs an ODL that is not set-representable. This example is quite elaborate. A main result...
Orthomodular lattices with fully nontrivial commutators
An orthomodular lattice is said to have fully nontrivial commutator if the commutator of any pair is different from zero. In this note we consider the class of all orthomodular lattices with fully nontrivial commutators. We show that this class forms a quasivariety, we describe it in terms of quasiidentities and situate important types of orthomodular lattices (free lattices, Hilbertian lattices, etc.) within this class. We also show that the quasivariety in question is not a variety answering...
Orthomodular lattices with state-separated noncompatible pairs
In the logico-algebraic foundation of quantum mechanics one often deals with the orthomodular lattices (OML) which enjoy state-separating properties of noncompatible pairs (see e.g. , and ). These properties usually guarantee reasonable “richness” of the state space—an assumption needed in developing the theory of quantum logics. In this note we consider these classes of OMLs from the universal algebra standpoint, showing, as the main result, that these classes form quasivarieties. We also illustrate...
Orthorings
Certain ring-like structures, so-called orthorings, are introduced which are in a natural one-to-one correspondence with lattices with 0 every principal ideal of which is an ortholattice. This correspondence generalizes the well-known bijection between Boolean rings and Boolean algebras. It turns out that orthorings have nice congruence and ideal properties.
-compatible identities and their applications to classical algebras
Pairwise and General Independence of Abstract Algebras.
Pairwise intersections of Słupecki type maximal partial clones.
Partial Abelian H_u-Monoids
Partial Boolean algebras in a broader sense and Boolean embeddings
Partial monounary algebras with common closed quasi-endomorphisms
Partial monounary algebras with common congruence relations
Partial monounary algebras with common quasi-endomorphisms
Partially-2-homogeneous monounary algebras
This paper is a continuation of [5], where -homogeneous and -set-homogeneous algebras were defined. The definitions are analogous to those introduced by Fraïssé [2] and Droste, Giraudet, Macpherson, Sauer [1] for relational structures. In [5] we found all 2-homogeneous and all 2-set-homogeneous monounary algebras when the homogenity is considered with respect to subalgebras, to connected subalgebras and with respect to connected partial subalgebras, respectively. The results of [3], where all...
Partially-additive monoids
Partielle Algebren in Initialkategorien.
Partitions and congruences in algebras. I. Basic properties
Partitions and congruences in algebras. II. Modular and distributive equalities, complements
Partitions and congruences in algebras. III. Commutativity of congruences