On commuting generalized inverses in semigroups.
On complete -ideals in semigroups
On congruence permutable -sets
An algebraic structure is said to be congruence permutable if its arbitrary congruences and satisfy the equation , where denotes the usual composition of binary relations. To an arbitrary -set satisfying , we assign a semigroup on the base set containing a zero element , and examine the connection between the congruence permutability of the -set and the semigroup .
On finitely generated monoids of matrices with entries in
On finitely generated submonoids of N k
On finitely generated subsemigroups of a free semigroup.
On finiteness conditions for Rees matrix semigroups
Let be a Rees matrix semigroup where is a semigroup, and are index sets, and is a matrix with entries from , and let be the ideal generated by all the entries of . If has finite index in , then we prove that is periodic (locally finite) if and only if is periodic (locally finite). Moreover, residual finiteness and having solvable word problem are investigated.
On Free Commutative Groupoids
On free commutative groupoids.
On free products of bands.
On free products of bicyclic monoids.
On generating regular elements in the semigroup of binary relations.
On graph products of automatic monoids
The graph product is an operator mixing direct and free products. It is already known that free products and direct products of automatic monoids are automatic. The main aim of this paper is to prove that graph products of automatic monoids of finite geometric type are still automatic. A similar result for prefix-automatic monoids is established.
On graph products of automatic monoids
The graph product is an operator mixing direct and free products. It is already known that free products and direct products of automatic monoids are automatic. The main aim of this paper is to prove that graph products of automatic monoids of finite geometric type are still automatic. A similar result for prefix-automatic monoids is established.
On low-complexity bi-infinite words and their factors
In this paper we study bi-infinite words on two letters. We say that such a word has stiffness if the number of different subwords of length equals for all sufficiently large. The word is called -balanced if the numbers of occurrences of the symbol a in any two subwords of the same length differ by at most . In the present paper we give a complete description of the class of bi-infinite words of stiffness and show that the number of subwords of length from this class has growth order...
On optimal factorization of free semigroups into free subsemigroups.
On permutation properties in groups and semigroups.
On presentations of Brauer-type monoids
We obtain presentations for the Brauer monoid, the partial analogue of the Brauer monoid, and for the greatest factorizable inverse submonoid of the dual symmetric inverse monoid. In all three cases we apply the same approach, based on the realization of all these monoids as Brauer-type monoids.
On principal ideals of triply-generated telescopic semigroups.
On -commutativity of -permutable semigroups.