{"abstract":[{"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.","lang":"eng"}],"publication_identifier":{"issn":["2664-1690"]},"has_accepted_license":"1","title":"A symbolic SAT-based algorithm for almost-sure reachability with small strategies in POMDPs","oa_version":"Published Version","related_material":{"record":[{"relation":"later_version","status":"public","id":"1166"}]},"date_updated":"2023-02-21T16:24:05Z","language":[{"iso":"eng"}],"page":"23","file":[{"relation":"main_file","checksum":"f0fa31ad8161ed655137e94012123ef9","date_updated":"2020-07-14T12:46:57Z","file_name":"IST-2015-325-v2+1_main.pdf","access_level":"open_access","content_type":"application/pdf","date_created":"2018-12-12T11:53:05Z","file_id":"5466","file_size":412379,"creator":"system"}],"author":[{"full_name":"Chatterjee, Krishnendu","first_name":"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"},{"id":"378E0060-F248-11E8-B48F-1D18A9856A87","full_name":"Davies, Jessica","first_name":"Jessica","last_name":"Davies"}],"publisher":"IST Austria","month":"11","_id":"5443","doi":"10.15479/AT:IST-2015-325-v2-1","alternative_title":["IST Austria Technical Report"],"ddc":["000"],"department":[{"_id":"KrCh"}],"user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","file_date_updated":"2020-07-14T12:46:57Z","type":"technical_report","date_created":"2018-12-12T11:39:22Z","status":"public","citation":{"mla":"Chatterjee, Krishnendu, et al. <i>A Symbolic SAT-Based Algorithm for Almost-Sure Reachability with Small Strategies in POMDPs</i>. IST Austria, 2015, doi:<a href=\"https://doi.org/10.15479/AT:IST-2015-325-v2-1\">10.15479/AT:IST-2015-325-v2-1</a>.","ieee":"K. Chatterjee, M. Chmelik, and J. Davies, <i>A symbolic SAT-based algorithm for almost-sure reachability with small strategies in POMDPs</i>. 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.","apa":"Chatterjee, K., Chmelik, M., &#38; Davies, J. (2015). <i>A symbolic SAT-based algorithm for almost-sure reachability with small strategies in POMDPs</i>. IST Austria. <a href=\"https://doi.org/10.15479/AT:IST-2015-325-v2-1\">https://doi.org/10.15479/AT:IST-2015-325-v2-1</a>","chicago":"Chatterjee, Krishnendu, Martin Chmelik, and Jessica Davies. <i>A Symbolic SAT-Based Algorithm for Almost-Sure Reachability with Small Strategies in POMDPs</i>. IST Austria, 2015. <a href=\"https://doi.org/10.15479/AT:IST-2015-325-v2-1\">https://doi.org/10.15479/AT:IST-2015-325-v2-1</a>.","ama":"Chatterjee K, Chmelik M, Davies J. <i>A Symbolic SAT-Based Algorithm for Almost-Sure Reachability with Small Strategies in POMDPs</i>. IST Austria; 2015. doi:<a href=\"https://doi.org/10.15479/AT:IST-2015-325-v2-1\">10.15479/AT:IST-2015-325-v2-1</a>","short":"K. Chatterjee, M. Chmelik, J. Davies, A Symbolic SAT-Based Algorithm for Almost-Sure Reachability with Small Strategies in POMDPs, IST Austria, 2015."},"day":"06","date_published":"2015-11-06T00:00:00Z","pubrep_id":"362","year":"2015","publication_status":"published","oa":1}