Remarks on the paper "M. Kolibiar, On a construction of semigroups"

Attila Nagy

Published 2015-04-27Version 1

In his paper "On a construction of semigroups", M. Kolibiar gave a construction for a semigroup T (beginning from a semigroup S) which is said to be derived from the semigroup S by a {\theta}-construction. He assered that every semigroup T can be derived from the factor semigroup T/{\theta}(T) by a {\theta}-construction, where {\theta}(T) is the congruence on T defined by: (a,b) is in {\theta}(T) if and only if xa = xb for all x of T. Unfortunately, the paper contains some incorrect part. In our present paper we give a revision of the paper.