English

Constrained Synchronization for Commutative Automata and Automata with Simple Idempotents

Formal Languages and Automata Theory 2021-09-08 v1 Computational Complexity

Abstract

For general input automata, there exist regular constraint languages such that asking if a given input automaton admits a synchronizing word in the constraint language is PSPACE-complete or NP-complete. Here, we investigate this problem for commutative automata over an arbitrary alphabet and automata with simple idempotents over a binary alphabet as input automata. The latter class contains, for example, the \v{C}ern\'y family of automata. We find that for commutative input automata, the problem is always solvable in polynomial time, for every constraint language. For input automata with simple idempotents over a binary alphabet and with a constraint language given by a partial automaton with up to three states, the constrained synchronization problem is also solvable in polynomial time.

Keywords

Cite

@article{arxiv.2109.02743,
  title  = {Constrained Synchronization for Commutative Automata and Automata with Simple Idempotents},
  author = {Stefan Hoffmann},
  journal= {arXiv preprint arXiv:2109.02743},
  year   = {2021}
}
R2 v1 2026-06-24T05:44:09.505Z