Primitive classes of algebras with two unary idempotent operations, containing all algebraic categories as full subcategories
Principal dual ideals in lattices of primitive classes
Principal tolerances on lattices
Principal tolerances on lattices
Products of mode varieties and algebras of subalgebras
Products of multialgebras and their fundamental algebras.
Produit symétrisé
Produkte von Kongruenzklassengeometrien universeller Algebren.
Projection representable relations on Menger -semigroups
Abstract characterizations of relations of nonempty intersection, inclusion end equality of domains for partial -place functions are presented. Representations of Menger -semigroups by partial -place functions closed with respect to these relations are investigated.
Projections of relations
A projection of a relation is defined as a relation of reduced arity. The paper deals with projections of relations in coherence with their reflexivity, symmetry, completeness, regularity, cyclicity and other properties. Relationships between projections of hulls and hulls of projections are also studied.
Proper automorphisms of universal algebras.
Proper congruences do not imply a modular congruence lattice
Proper hypersubstitutions of some generalizations of lattices and Boolean algebras
Properties of relatively pseudocomplemented directoids
The concept of a relatively pseudocomplemented directoid was introduced recently by the first author. It was shown that the class of relatively pseudocomplemented directoids forms a variety whose axiom system contains seven identities. The aim of this paper is three-fold. First we show that these identities are not independent and their independent subset is presented. Second, we modify the adjointness property known for relatively pseudocomplemented semilattices in the way which is suitable for...
Proprietà metamatematiche di alcune classi di algebre
Propriétés catégorielles dans la théorie des algèbres universelles
Propriétés de permanence et existence de réalisations minimales pour les algèbres multisortes
Protomodular quasivarieties of universal algebras
Pseudocomplements in sum-ordered partial semirings
We study a particular way of introducing pseudocomplementation in ordered semigroups with zero, and characterise the class of those pseudocomplemented semigroups, termed g-semigroups here, that admit a Glivenko type theorem (the pseudocomplements form a Boolean algebra). Some further results are obtained for g-semirings - those sum-ordered partially additive semirings whose multiplicative part is a g-semigroup. In particular, we introduce the notion of a partial Stone semiring and show that several...
Pseudogroupoids and commutators.