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.
Clone compatible identities and clone extensions of algebras
Clone properties of topological spaces
Clone properties are the properties expressible by the first order sentence of the clone language. The present paper is a contribution to the field of problems asking when distinct sentences of the language determine distinct topological properties. We fully clarify the relations among the rigidity, the fix-point property, the image-determining property and the coconnectedness.
Clones closed with respect to permutation groups or transformation semigroups.
Clones, coclones and coconnected spaces.
Clones in topology and algebra.
Clones on regular cardinals
We investigate the structure of the lattice of clones on an infinite set X. We first observe that ultrafilters naturally induce clones; this yields a simple proof of Rosenberg’s theorem: there are maximal (= “precomplete”) clones on a set of size λ. The clones we construct do not contain all unary functions. We then investigate clones that do contain all unary functions. Using a strong negative partition theorem from pcf theory we show that for cardinals λ (in particular, for all successors of...
Closed sets of universal Horn formulas for many-sorted (partial) algebras
Closedness properties of internal relations. I. A unified approach to Mal'tsev, unital and subtractive categories.
Closedness properties of internal relations. II: Bourn localization.
Closedness properties of internal relations. IV: Expressing additivity of a category via subtractivity.
Closure Łukasiewicz algebras
In this paper, the variety of closure n-valued Łukasiewicz algebras, that is, Łukasiewicz algebras of order n endowed with a closure operator, is investigated. The lattice of subvarieties in the particular case in which the open elements form a three-valued Heyting algebra is obtained.
Closure properties for relational systems with given endomorphism structure
Cogeneration and minimal realization (Preliminary communication)
Coherence and weak coherence in the square of algebras