The symmetric Post Correspondence Problem, and errata for the freeness problem for matrix semigroups
Group Theory
2022-07-14 v2 Computational Complexity
Abstract
We define the symmetric Post Correspondence Problem (PCP) and prove that it is undecidable. As an application we show that the original proof of undecidability of the freeness problem for 3-by-3 integer matrix semigroups works for the symmetric PCP, but not for the PCP in general.
Cite
@article{arxiv.2112.02408,
title = {The symmetric Post Correspondence Problem, and errata for the freeness problem for matrix semigroups},
author = {J. C. Birget and A. L. Talambutsa},
journal= {arXiv preprint arXiv:2112.02408},
year = {2022}
}
Comments
12 pages. Small corrections and clarifications were added in version 2