On completely meet-irreducible elements in compactly generated lattices
On completeness and direction in fuzzy relational systems.
The concepts of bounded subset, complete subset and directed subset, wich are well known in the context of partially ordered sets (X,≤), are extended in order to become appliable, with coherence, in fuzzy relational systems (X,R). The properties of these generalized structures are analyzed and operative exemples of them are presented.
On completion of cyclically ordered sets
On completions of linearly ordered groups
On congruence distributivity of ordered algebras with constants
We define the order-congruence distributivity at 0 and order- congruence n-distributivity at 0 of ordered algebras with a nullary operation 0. These notions are generalizations of congruence distributivity and congruence n-distributivity. We prove that a class of ordered algebras with a nullary operation 0 closed under taking subalgebras and direct products is order-congruence distributive at 0 iff it is order-congruence n-distributive at 0. We also characterize such classes by a Mal'tsev condition....
On congruence lattices in a category
On congruence lattices of regular semigroups with Q-inverse transversals.
On congruences and ideals of partially ordered quasigroups
Some results concerning congruence relations on partially ordered quasigroups (especially, Riesz quasigroups) and ideals of partially ordered loops are presented. These results generalize the assertions which were proved by Fuchs in [5] for partially ordered groups and Riesz groups.
On congruences of the lattices
On congruences of ...x-normal semigroups.
On connections between information systems, rough sets and algebraic logic
In this note we remark upon some relationships between the ideas of an approximation space and rough sets due to Pawlak ([9] and [10]) and algebras related to the study of algebraic logic - namely, cylindric algebras, relation algebras, and Stone algebras. The paper consists of three separate observations. The first deals with the family of approximation spaces induced by the indiscernability relation for different sets of attributes of an information system. In [3] the family of closure operators...
On Conrad's partial order relation on semiprime rings and semigroups.
On constructing a distributive lattice from a partially ordered set with DCC
On constructive nilpotent groups.
On contexts of direct products, ordinal sums and ordinal products
On convex constructions in lattices
On convex linearly ordered subgroups of an -group
On convexities of -groups
On convexities of lattices
On convexly isomorphic posets