Characterization of pointed varieties of universal algebras with normal projections.
Characterization of protomodular varieties of universal algebras.
Characterizations of certain general and reproductive solutions of arbitrary equations
Characterizations of certain monounary algebras. I
Characterizations of certain monounary algebras. II
Characterizations of commuting relations
Characterizations of Hamiltonian algebras
Characterizing binary discriminator algebras
The concept of the (dual) binary discriminator was introduced by R. Halas, I. G. Rosenberg and the author in 1999. We study finite algebras having the (dual) discriminator as a term function. In particular, a simple characterization is obtained for such algebras with a majority term function.
Characterizing matrices with -simple image eigenspace in max-min semiring
A matrix is said to have -simple image eigenspace if any eigenvector belonging to the interval is the unique solution of the system in . The main result of this paper is a combinatorial characterization of such matrices in the linear algebra over max-min (fuzzy) semiring. The characterized property is related to and motivated by the general development of tropical linear algebra and interval analysis, as well as the notions of simple image set and weak robustness (or weak stability) that...
Characterizing pure, cryptic and Clifford inverse semigroups
An inverse semigroup is pure if , , implies ; it is cryptic if Green’s relation on is a congruence; it is a Clifford semigroup if it is a semillatice of groups. We characterize the pure ones by the absence of certain subsemigroups and a homomorphism from a concrete semigroup, and determine minimal nonpure varieties. Next we characterize the cryptic ones in terms of their group elements and also by a homomorphism of a semigroup constructed in the paper. We also characterize groups and...
Characterizing tolerance trivial finite algebras
An algebra is tolerance trivial if where is the lattice of all tolerances on . If contains a Mal’cev function compatible with each , then is tolerance trivial. We investigate finite algebras satisfying also the converse statement.
Church-Rosser property and decidability of monadic theories of unary algebras
Class preserving mappings of equivalence systems
By an equivalence system is meant a couple where is a non-void set and is an equivalence on . A mapping of an equivalence system into is called a class preserving mapping if for each . We will characterize class preserving mappings by means of permutability of with the equivalence induced by .
Classes of graphs definable by graph algebra identities or quasi-identities
Classi e schemi ideali. Congruenze ideali V
Classification de catégories
Classification of Maps by Their Membership in Maximal Clones That Contain Minimum and Complement
Clausal relations and C-clones
We introduce a special set of relations called clausal relations. We study a Galois connection Pol-CInv between the set of all finitary operations on a finite set D and the set of clausal relations, which is a restricted version of the Galois connection Pol-Inv. We define C-clones as the Galois closed sets of operations with respect to Pol-CInv and describe the lattice of all C-clones for the Boolean case D = {0,1}. Finally we prove certain results about C-clones over a larger set.
Clifford congruences on generalized quasi-orthodox GV-semigroups
A semigroup S is said to be completely π-regular if for any a ∈ S there exists a positive integer n such that aⁿ is completely regular. A completely π-regular semigroup S is said to be a GV-semigroup if all the regular elements of S are completely regular. The present paper is devoted to the study of generalized quasi-orthodox GV-semigroups and least Clifford congruences on them.
Clone automorphisms and hypersubstitutions.