English

An NP-hardness Result on the Monoid Frobenius Problem

Discrete Mathematics 2008-06-30 v3 Computational Complexity

Abstract

The following problem is NP-hard: given a regular expression EE, decide if EE^* is not co-finite.

Cite

@article{arxiv.0805.4049,
  title  = {An NP-hardness Result on the Monoid Frobenius Problem},
  author = {Zhi Xu and J. Shallit},
  journal= {arXiv preprint arXiv:0805.4049},
  year   = {2008}
}

Comments

2 pages, working paper; an error in Problem 5 is corrected

R2 v1 2026-06-21T10:44:23.861Z