Constructions of (2,n)-varieties of groupoids for n = 7, 8, 9
Constructions of cell algebras
A construction of cell algebras is introduced and some of their properties are investigated. A particular case of this construction for lattices of nets is considered.
Constructions of color schemes
Constructions over tournaments
We investigate tournaments that are projective in the variety that they generate, and free algebras over partial tournaments in that variety. We prove that the variety determined by three-variable equations of tournaments is not locally finite. We also construct infinitely many finite, pairwise incomparable simple tournaments.
Contextual grammars vs. context-free algebras
Controllable and tolerable generalized eigenvectors of interval max-plus matrices
By max-plus algebra we mean the set of reals equipped with the operations and for A vector is said to be a generalized eigenvector of max-plus matrices if for some . The investigation of properties of generalized eigenvectors is important for the applications. The values of vector or matrix inputs in practice are usually not exact numbers and they can be rather considered as values in some intervals. In this paper the properties of matrices and vectors with inexact (interval) entries...
Convex automorphisms of partial monounary algebras
Convex sets in algebras
Convex subsets of partial monounary algebras
Coproducts of ideal monads
The question of how to combine monads arises naturally in many areas with much recent interest focusing on the coproduct of two monads. In general, the coproduct of arbitrary monads does not always exist. Although a rather general construction was given by Kelly [Bull. Austral. Math. Soc. 22 (1980) 1–83], its generality is reflected in its complexity which limits the applicability of this construction. Following our own research [C. Lüth and N. Ghani, Lect. Notes Artif. Intell. 2309 (2002) 18–32],...
Coproducts of Ideal Monads
The question of how to combine monads arises naturally in many areas with much recent interest focusing on the coproduct of two monads. In general, the coproduct of arbitrary monads does not always exist. Although a rather general construction was given by Kelly [Bull. Austral. Math. Soc.22 (1980) 1–83], its generality is reflected in its complexity which limits the applicability of this construction. Following our own research [C. Lüth and N. Ghani, Lect. Notes Artif. Intell.2309 (2002)...
Coregularity of endomorphism monoids of unars
Corrigendum à l'article "Sur la construction de certaines MS-algèbres" (Port. Math., 39(1-4) (1980), 489-496)
Corrigendum to "Operators and products in the lattice of existence varieties of regular semigroups".
Corrigendum to "The join of the pseudovarieties of idempotent semigroups and locally trivial semigroups".
Covering condition in the lattice of radical classes of linearly ordered groups
Coverings in the lattice of quasivarieties of -groups.
Covers in the lattice of varieties of -groups.
C-S-maximal superassociative systems. II.
Cyclically ordered sets as partial algebras
A representation of cyclically ordered sets by means of partial semigroups with an additional unary operation is constructed.