Sets of lengths do not characterize numerical monoids.
Simple zeropotent paramedial groupoids are balanced
This short note is a continuation of and and its purpose is to show that every simple zeropotent paramedial groupoid containing at least three elements is strongly balanced in the sense of .
Some properties of -operations
In the paper the problem of mathematical properties of -operations and weak -operations introduced by the author for interpretation of connectives “and”, “or”, and “also” in fuzzy rules is considered. In previous author’s papers some interesting properties of fuzzy systems with these operations were shown. These operations are weaker than triangular norms used commonly for a fuzzy system described by set of rules of the type if – then. Monotonicity condition, required for triangular norms, is...
Some remarks on certain partially ordered semigroups.
Some remarks on Lorenzen -group of partly ordered groups
Subdirectly irreducible right commutative semigroups.
Subsemigroups of Finitely Generated Groups with Divisor-Theory.
Taming the wild in impartial combinatorial games.
Terms and semiterms
The covariety of perfect numerical semigroups with fixed Frobenius number
Let be a numerical semigroup. We say that is an isolated gap of if A numerical semigroup without isolated gaps is called a perfect numerical semigroup. Denote by the multiplicity of a numerical semigroup . A covariety is a nonempty family of numerical semigroups that fulfills the following conditions: there exists the minimum of the intersection of two elements of is again an element of , and for all such that We prove that the set is a perfect numerical semigroup with...
The factorizable transformation semigroups.
The Frobenius number of geometric sequences.
The intersection graph of a simply ordered semigroup.
The least separative congruence on a weakly commutative semigroup
The local catenativity of DOL-sequences in free commutative monoids is decidable in the binary case
The number of commutative semigroups of order N.
The rank of a commutative semigroup
The concept of rank of a commutative cancellative semigroup is extended to all commutative semigroups by defining as the supremum of cardinalities of finite independent subsets of . Representing such a semigroup as a semilattice of (archimedean) components , we prove that is the supremum of ranks of various . Representing a commutative separative semigroup as a semilattice of its (cancellative) archimedean components, the main result of the paper provides several characterizations...
The semigroup of nonempty finite subsets of integers.
The semigroup of nonempty finite subsets of rationals.
The structure of commutative ideal semigroups.