The lattice of subautomata of an automaton: A survey.
The lattice of varieties of fibered automata
The class of all fibered automata is a variety of two-sorted algebras. This paper provides a full description of the lattice of varieties of fibred automata.
The logic of categories of partial functions and its applications [Book]
The minimal closed monoids for the Galois connection -
The minimal nontrivial endomorphism monoids of congruence lattices of algebras defined on a finite set are described. They correspond (via the Galois connection -) to the maximal nontrivial congruence lattices investigated and characterized by the authors in previous papers. Analogous results are provided for endomorphism monoids of quasiorder lattices .
The minimal extension of sequences III. On problem 16 of Grätzer and Kisielewicz
The main result of this paper is a description of totally commutative idempotent groupoids. In particular, we show that if an idempotent groupoid (G,·) has precisely m ≥ 2 distinct essentially binary polynomials and they are all commutative, then G contains a subgroupoid isomorphic to the groupoid described below. In [2], this fact was proved for m = 2.
The monoid of generalized hypersubstitutions of type τ = (n)
A (usual) hypersubstitution of type τ is a function which takes each operation symbol of the type to a term of the type, of the same arity. The set of all hypersubstitutions of a fixed type τ forms a monoid under composition, and semigroup properties of this monoid have been studied by a number of authors. In particular, idempotent and regular elements, and the Green’s relations, have been studied for type (n) by S.L. Wismath. A generalized hypersubstitution of type τ=(n) is a mapping σ which takes...
The monoid of strong endomorphisms of a graph.
The notion of an elementary subsystem for a Boolean-valued relational system
The one-block property in varieties of semigroups.
The order of generalized hypersubstitutions of type .
The positive and generalized discriminators don't exist
In this paper it is proved that there does not exist a function for the language of positive and generalized conditional terms that behaves the same as the discriminator for the language of conditional terms.
The Rees Congruence in Universal Algebras
The refinement of two isomorphic generalized lexicographic products
The semigroup generated by certain operators on the congruence lattice of a Clifford semigroup.
The set of ergodic groups of universal algebras
The set of hypergroups with operators which are constructed from a set with two elements
The Słupecki criterion by duality
A method is presented for proving primality and functional completeness theorems, which makes use of the operation-relation duality. By the result of Sierpiński, we have to investigate relations generated by the two-element subsets of only. We show how the method applies for proving Słupecki’s classical theorem by generating diagonal relations from each pair of k-tuples.
The strong amalgamation property
The structure of closure congruences
The structure of commutative ideal semigroups.