English

The Satisfiability and Validity Problems for Probabilistic Computational Tree Logic are Highly Undecidable

Logic in Computer Science 2025-05-01 v2

Abstract

The Probabilistic Computational Tree Logic (PCTL) is the main specification formalism for discrete probabilistic systems modeled by Markov chains. Despite serious research attempts, the decidability of PCTL satisfiability and validity problems remained unresolved for 30 years. We show that both problems are highly undecidable, i.e., beyond the arithmetical hierarchy. Consequently, there is no sound and complete deductive system for PCTL.

Keywords

Cite

@article{arxiv.2504.19207,
  title  = {The Satisfiability and Validity Problems for Probabilistic Computational Tree Logic are Highly Undecidable},
  author = {Miroslav Chodil and Antonín Kučera},
  journal= {arXiv preprint arXiv:2504.19207},
  year   = {2025}
}
R2 v1 2026-06-28T23:12:51.090Z