English

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

Group Theory 2016-02-01 v5

Abstract

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

Keywords

Cite

@article{arxiv.1504.07181,
  title  = {Remarks on the paper "M. Kolibiar, On a construction of semigroups"},
  author = {Attila Nagy},
  journal= {arXiv preprint arXiv:1504.07181},
  year   = {2016}
}

Comments

Version v5 differs from the published and the earlier versions in the following: some part of the proof of Theorem 2 are clarified, and some typing errors are corrected