English

A Sharper Upper Bound for the Separating Words Problem

Formal Languages and Automata Theory 2025-04-03 v2 Number Theory

Abstract

We show that for any two distinct words s1,s2 s_1, s_2 over an arbitrary alphabets, there exists a deterministic finite automaton with O(log2n) O(\log^2 n) states that accepts s1 s_1 and rejects s2 s_2 . This improves the previous upper bound of O(n1/3log7n)O(n^{1/3}\log^7 n)

Keywords

Cite

@article{arxiv.2503.23184,
  title  = {A Sharper Upper Bound for the Separating Words Problem},
  author = {Bogdan C. Dumitru},
  journal= {arXiv preprint arXiv:2503.23184},
  year   = {2025}
}

Comments

An error has been identified in the proof of Theorem 1. Correcting the argument presented yields an upper bound which does not improve upon existing results (e.g., [Chase 2020]), so this paper does not in fact provide an improved upper bound. We therefore withdraw our claim of a stronger result

R2 v1 2026-06-28T22:39:08.987Z