On equalizer-flat and pullback-flat acts.
On equationally compact semigroups.
On exclusive semigroups.
On expressing commutativity by finite Church-Rosser presentations : a note on commutative monoids
On extensions of partial -operators
On factor S-sets of monoids modulo submonoids.
On factorisations onto the Bicyclic semigroup.
On finite lattices which are embeddable in subsemigroup lattices.
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 products of bicyclic monoids.
On free subsemigroups.
On general linear semigroups.
On generalized conditionally commutative semigroups
On generalized kernels.
On generalized kernels II.
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 groups of units in a special class of monoids.
On ideal extensions of completely simple semigroups.