English

A note-question on partitions of semigroups

Combinatorics 2015-08-31 v1

Abstract

Given a semigroup SS and an nn-partition P\mathcal{P} of SS, nNn\in \mathbb{N}, do there exist APA\in \mathcal{P} and a subset FF of SS such that S=F1{xS:xAA}S=F ^{-1} \{x \in S: x A \bigcap A\neq\emptyset\} and Fn|F |\leq n? We give an affirmative answer provided that either SS is finite or n=2n=2.

Keywords

Cite

@article{arxiv.1508.07133,
  title  = {A note-question on partitions of semigroups},
  author = {Igor Protasov and Ksenia Protasova},
  journal= {arXiv preprint arXiv:1508.07133},
  year   = {2015}
}
R2 v1 2026-06-22T10:43:33.782Z