English

The Diagonal Problem for Higher-Order Recursion Schemes is Decidable

Formal Languages and Automata Theory 2016-05-03 v1 Logic in Computer Science

Abstract

A non-deterministic recursion scheme recognizes a language of finite trees. This very expressive model can simulate, among others, higher-order pushdown automata with collapse. We show decidability of the diagonal problem for schemes. This result has several interesting consequences. In particular, it gives an algorithm that computes the downward closure of languages of words recognized by schemes. In turn, this has immediate application to separability problems and reachability analysis of concurrent systems.

Keywords

Cite

@article{arxiv.1605.00371,
  title  = {The Diagonal Problem for Higher-Order Recursion Schemes is Decidable},
  author = {Lorenzo Clemente and Paweł Parys and Sylvain Salvati and Igor Walukiewicz},
  journal= {arXiv preprint arXiv:1605.00371},
  year   = {2016}
}

Comments

technical report; to appear in LICS'16

R2 v1 2026-06-22T13:46:10.362Z