English

The Recursive Arrival Problem

Computational Complexity 2023-10-03 v1

Abstract

We study an extension of the Arrival problem, called Recursive Arrival, inspired by Recursive State Machines, which allows for a family of switching graphs that can call each other in a recursive way. We study the computational complexity of deciding whether a Recursive Arrival instance terminates at a given target vertex. We show this problem is contained in NP \cap coNP, and we show that a search version of the problem lies in UEOPL, and hence in EOPL = PLS \cap PPAD. Furthermore, we show P-hardness of the Recursive Arrival decision problem. By contrast, the current best-known hardness result for Arrival is PL-hardness.

Keywords

Cite

@article{arxiv.2310.01004,
  title  = {The Recursive Arrival Problem},
  author = {Thomas Webster},
  journal= {arXiv preprint arXiv:2310.01004},
  year   = {2023}
}

Comments

In Proceedings GandALF 2023, arXiv:2309.17318

R2 v1 2026-06-28T12:38:01.472Z