Partial orders and their semigroups of closed relations.
Partial orders, closed relations and their automorphisms.
Perfectly supportable semigroups are σ-discrete in each Hausdorff shift-invariant topology
In this paper we introduce perfectly supportable semigroups and prove that they are σ-discrete in each Hausdorff shiftinvariant topology. The class of perfectly supportable semigroups includes each semigroup S such that FSym(X) ⊂ S ⊂ FRel(X) where FRel(X) is the semigroup of finitely supported relations on an infinite set X and FSym(X) is the group of finitely supported permutations of X.
Permutable transformation semigroups.
Points de continuité à gauche d'une action de semi-groupe.
Polynomial functions over commutative semigroups.
Positive definite functions on discrete commutative semigroups.
Positive-definite functions on discrete commutative semigroups: Errata and supplements.
Presentation of the singular part of the Brauer monoid
We obtain a presentation for the singular part of the Brauer monoid with respect to an irreducible system of generators consisting of idempotents. As an application of this result we get a new construction of the symmetric group via connected sequences of subsets. Another application describes the lengths of elements in the singular part of the Brauer monoid with respect to the system of generators mentioned above.
Presentations for subsemigroups of
Let be an -chain. We give presentations for the following transformation semigroups: the semigroup of full order-decreasing mappings of , the semigroup of partial one-to-one order-decreasing mappings of , the semigroup of full order-preserving and order-decreasing mappings of , the semigroup of partial one-to-one order-preserving and order-decreasing mappings of , and the semigroup of partial order-preserving and order-decreasing mappings of .
Presentations of alternating semigroups.
Primární rozklady
Prime elements in the semigroup of finite types of partially ordered sets in cardinal multiplication
Principal continuum congruences, regular ...-classes and local subsemigroups.
Principal ideals in the semigroup of binary relations on a finite set: What happens when one element is added to the set.
Product of idempotents in finite full transformation semigroups.
Products of four idempotents in finite full transformation semigroups.
Products of Idempotent Endomorphisms of Free Acts of Infinite Rank.
Products OF IDEMPOTENT ORDER-PRESERVING TRANSFORMATIONS OF ARBITRARY CHAINS.
Properties of a pair of functions which generate a dense subsemigroup of S(X).