English

Perfectly supportable semigroups are \sigma-discrete in each Hausdorff shift-invariant topology

General Topology 2014-12-04 v1 Group Theory

Abstract

In this paper we introduce perfectly supportable semigroups and prove that they are \sigma-discrete in each Hausdorff shift-invariant topology. The class of perfectly supportable semigroups includes each subsemigroup S of the semigroup FRel(X) of finitely supported relations on an infinite set X such that S contains the group FSym(X) of finitely supported permutations of X.

Keywords

Cite

@article{arxiv.1112.5727,
  title  = {Perfectly supportable semigroups are \sigma-discrete in each Hausdorff shift-invariant topology},
  author = {Taras Banakh and Igor Guran},
  journal= {arXiv preprint arXiv:1112.5727},
  year   = {2014}
}

Comments

6 pages