--- _id: '5443' abstract: - lang: eng text: POMDPs are standard models for probabilistic planning problems, where an agent interacts with an uncertain environment. We study the problem of almost-sure reachability, where given a set of target states, the question is to decide whether there is a policy to ensure that the target set is reached with probability 1 (almost-surely). While in general the problem is EXPTIME-complete, in many practical cases policies with a small amount of memory suffice. Moreover, the existing solution to the problem is explicit, which first requires to construct explicitly an exponential reduction to a belief-support MDP. In this work, we first study the existence of observation-stationary strategies, which is NP-complete, and then small-memory strategies. We present a symbolic algorithm by an efficient encoding to SAT and using a SAT solver for the problem. We report experimental results demonstrating the scalability of our symbolic (SAT-based) approach. alternative_title: - IST Austria Technical Report author: - first_name: Krishnendu full_name: Chatterjee, Krishnendu id: 2E5DCA20-F248-11E8-B48F-1D18A9856A87 last_name: Chatterjee orcid: 0000-0002-4561-241X - first_name: Martin full_name: Chmelik, Martin id: 3624234E-F248-11E8-B48F-1D18A9856A87 last_name: Chmelik - first_name: Jessica full_name: Davies, Jessica id: 378E0060-F248-11E8-B48F-1D18A9856A87 last_name: Davies citation: ama: Chatterjee K, Chmelik M, Davies J. A Symbolic SAT-Based Algorithm for Almost-Sure Reachability with Small Strategies in POMDPs. IST Austria; 2015. doi:10.15479/AT:IST-2015-325-v2-1 apa: Chatterjee, K., Chmelik, M., & Davies, J. (2015). A symbolic SAT-based algorithm for almost-sure reachability with small strategies in POMDPs. IST Austria. https://doi.org/10.15479/AT:IST-2015-325-v2-1 chicago: Chatterjee, Krishnendu, Martin Chmelik, and Jessica Davies. A Symbolic SAT-Based Algorithm for Almost-Sure Reachability with Small Strategies in POMDPs. IST Austria, 2015. https://doi.org/10.15479/AT:IST-2015-325-v2-1. ieee: K. Chatterjee, M. Chmelik, and J. Davies, A symbolic SAT-based algorithm for almost-sure reachability with small strategies in POMDPs. IST Austria, 2015. ista: Chatterjee K, Chmelik M, Davies J. 2015. A symbolic SAT-based algorithm for almost-sure reachability with small strategies in POMDPs, IST Austria, 23p. mla: Chatterjee, Krishnendu, et al. A Symbolic SAT-Based Algorithm for Almost-Sure Reachability with Small Strategies in POMDPs. IST Austria, 2015, doi:10.15479/AT:IST-2015-325-v2-1. short: K. Chatterjee, M. Chmelik, J. Davies, A Symbolic SAT-Based Algorithm for Almost-Sure Reachability with Small Strategies in POMDPs, IST Austria, 2015. date_created: 2018-12-12T11:39:22Z date_published: 2015-11-06T00:00:00Z date_updated: 2023-02-21T16:24:05Z day: '06' ddc: - '000' department: - _id: KrCh doi: 10.15479/AT:IST-2015-325-v2-1 file: - access_level: open_access checksum: f0fa31ad8161ed655137e94012123ef9 content_type: application/pdf creator: system date_created: 2018-12-12T11:53:05Z date_updated: 2020-07-14T12:46:57Z file_id: '5466' file_name: IST-2015-325-v2+1_main.pdf file_size: 412379 relation: main_file file_date_updated: 2020-07-14T12:46:57Z has_accepted_license: '1' language: - iso: eng month: '11' oa: 1 oa_version: Published Version page: '23' publication_identifier: issn: - 2664-1690 publication_status: published publisher: IST Austria pubrep_id: '362' related_material: record: - id: '1166' relation: later_version status: public status: public title: A symbolic SAT-based algorithm for almost-sure reachability with small strategies in POMDPs type: technical_report user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 year: '2015' ...