The cardinal and the idempotent number of various monoids of transformations on a finite chain.
The cardinalities of the Green classes of the free objects in varieties of bands.
The ...-category of a monoid.
The category of totally symmetric quasigroups is binding
The catenary degree of Krull monoids I
Let be a Krull monoid with finite class group such that every class contains a prime divisor (for example, a ring of integers in an algebraic number field or a holomorphy ring in an algebraic function field). The catenary degree of is the smallest integer with the following property: for each and each two factorizations of , there exist factorizations of such that, for each , arises from by replacing at most atoms from by at most new atoms. Under a very mild condition...
The catgorical theory of self-similarity.
The center of translational hull and the hull of center of semigroup
The characterisation of monoids by properties of their S-systems.
The cofinality of a band.
The common right multiple property in semigroup rings.
The commutativity relation in the symmetric semigroup.
The compression semigroup of a cone is connected.
The concept of structural regularity.
The congruence class of an idempotent in a regular semigroup.
The congruence extension property for algebraic semigroups.
The congruences on S(X) which commute with V.
The connection between a (3,2)-semigroup automaton and a semigroup automaton
The construction of semigroups from groups and semilattices
The core congruence on a monoid.
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...