On functions commuting with semigroups of transformations of algebras.
On general algebras
On generalized conditionally commutative semigroups
On generating large classes of Sheffer functions.
On Grätzer's problem of binary 1-step congruence schemes
On groups in which idempotent reducts form a chain
On hyperplanes and semispaces in max–min convex geometry
The concept of separation by hyperplanes and halfspaces is fundamental for convex geometry and its tropical (max-plus) analogue. However, analogous separation results in max-min convex geometry are based on semispaces. This paper answers the question which semispaces are hyperplanes and when it is possible to “classically” separate by hyperplanes in max-min convex geometry.
On ideal extensions of partial monounary algebras
In the present paper we introduce the notion of an ideal of a partial monounary algebra. Further, for an ideal of a partial monounary algebra we define the quotient partial monounary algebra . Let , be partial monounary algebras. We describe all partial monounary algebras such that is an ideal of and is isomorphic to .
On ideals and congruences in BCC-algebras
We introduce a new concept of ideals in BCC-algebras and describe connections between such ideals and congruences.
On ideals in De Morgan residuated lattices
In this paper, we introduce a new class of residuated lattices called De Morgan residuated lattices, we show that the variety of De Morgan residuated lattices includes important subvarieties of residuated lattices such as Boolean algebras, MV-algebras, BL-algebras, Stonean residuated lattices, MTL-algebras and involution residuated lattices. We investigate specific properties of ideals in De Morgan residuated lattices, we state the prime ideal theorem and the pseudo-complementedness of the ideal...
On ideals in Hilbert algebras
On independence of axioms of a certain class of ternary rings
On independence of the relations of epimorphy and embeddability on the variety of all lattices.
On infinite complete algebras
On Interassociativity and Related Questions
On interval decomposition lattices
Intervals in binary or n-ary relations or other discrete structures generalize the concept of interval in an ordered set. They are defined abstractly as closed sets of a closure system on a set V, satisfying certain axioms. Decompositions are partitions of V whose blocks are intervals, and they form an algebraic semimodular lattice. Lattice-theoretical properties of decompositions are explored, and connections with particular types of intervals are established.
On JP-semilattices of Begum and Noor
In recent papers, S. N. Begum and A. S. A. Noor have studied join partial semilattices (JP-semilattices) defined as meet semilattices with an additional partial operation (join) satisfying certain axioms. We show why their axiom system is too weak to be a satisfactory basis for the authors' constructions and proofs, and suggest an additional axiom for these algebras. We also briefly compare axioms of JP-semilattices with those of nearlattices, another kind of meet semilattices with a partial join...
On -ideals of semirings.
On k-radicals of Green's relations in semirings with a semilattice additive reduct
We introduce the k-radicals of Green's relations in semirings with a semilattice additive reduct, introduce the notion of left k-regular (right k-regular) semirings and characterize these semirings by k-radicals of Green's relations. We also characterize the semirings which are distributive lattices of left k-simple subsemirings by k-radicals of Green's relations.
On lattices embeddable into subsemigroup lattices. III: Nilpotent semigroups.