Limit-Sure Reachability for Small Memory Policies in POMDPs Is NP-Complete

Abstract

A standard model that arises in several applications in sequential decision-making is partially observable Markov decision processes (POMDPs) where a decision-making agent interacts with an uncertain environment. A basic objective in POMDPs is the reachability objective, where given a target set of states, the goal is to eventually arrive at one of them. The limit-sure problem asks whether reachability can be ensured with probability arbitrarily close to 1. In general, the limit-sure reachability problem for POMDPs is undecidable. However, in many practical cases, the most relevant question is the existence of policies with a small amount of memory. In this work, we study the limit-sure reachability problem for POMDPs with a fixed amount of memory. We establish that the computational complexity of the problem is NP-complete.

Cite

Text

Asadi et al. "Limit-Sure Reachability for Small Memory Policies in POMDPs Is NP-Complete." Proceedings of the Forty-first Conference on Uncertainty in Artificial Intelligence, 2025.

Markdown

[Asadi et al. "Limit-Sure Reachability for Small Memory Policies in POMDPs Is NP-Complete." Proceedings of the Forty-first Conference on Uncertainty in Artificial Intelligence, 2025.](https://mlanthology.org/uai/2025/asadi2025uai-limitsure/)

BibTeX

@inproceedings{asadi2025uai-limitsure,
  title     = {{Limit-Sure Reachability for Small Memory Policies in POMDPs Is NP-Complete}},
  author    = {Asadi, Ali and Chatterjee, Krishnendu and Saona, Raimundo and Shafiee, Ali},
  booktitle = {Proceedings of the Forty-first Conference on Uncertainty in Artificial Intelligence},
  year      = {2025},
  pages     = {238-256},
  volume    = {286},
  url       = {https://mlanthology.org/uai/2025/asadi2025uai-limitsure/}
}