{"doi":"10.1145/1970398.1970404","das_tickbox":"1","abstract":[{"text":"We consider two-player games played on a finite state space for an infinite number of rounds. The games are concurrent: in each round, the two players (player 1 and player 2) choose their moves independently and simultaneously; the current state and the two moves determine the successor state. We consider ω-regular winning conditions specified as parity objectives. Both players are allowed to use randomization when choosing their moves. We study the computation of the limit-winning set of states, consisting of the states where the sup-inf value of the game for player 1 is 1: in other words, a state is limit-winning if player 1 can ensure a probability of winning arbitrarily close to 1. We show that the limit-winning set can be computed in O(n2d+2) time, where n is the size of the game structure and 2d is the number of priorities (or colors). The membership problem of whether a state belongs to the limit-winning set can be decided in NP ∩ coNP. While this complexity is the same as for the simpler class of turn-based parity games, where in each state only one of the two players has a choice of moves, our algorithms are considerably more involved than those for turn-based games. This is because concurrent games do not satisfy two of the most fundamental properties of turn-based parity games. First, in concurrent games limit-winning strategies require randomization; and second, they require infinite memory.","lang":"eng"}],"external_id":{"isi":["000296202300006"]},"department":[{"_id":"KrCh"},{"_id":"ToHe"}],"publication_status":"published","intvolume":"        12","publication":"ACM Transactions on Computational Logic","date_created":"2018-12-11T12:02:51Z","year":"2011","publist_id":"3262","user_id":"2DF688A6-F248-11E8-B48F-1D18A9856A87","volume":12,"date_updated":"2026-07-07T14:02:38Z","project":[{"call_identifier":"FWF","grant_number":"S 11407_N23","_id":"25832EC2-B435-11E9-9278-68D0E5697425","name":"Rigorous Systems Engineering"},{"name":"Microsoft Research Faculty Fellowship","_id":"2587B514-B435-11E9-9278-68D0E5697425"}],"date_published":"2011-07-04T00:00:00Z","isi":1,"oa_version":"None","scopus_import":"1","related_material":{"record":[{"status":"public","relation":"later_version","id":"2054"}]},"title":"Qualitative concurrent parity games","citation":{"ama":"Chatterjee K, De Alfaro L, Henzinger TA. Qualitative concurrent parity games. <i>ACM Transactions on Computational Logic</i>. 2011;12(4). doi:<a href=\"https://doi.org/10.1145/1970398.1970404\">10.1145/1970398.1970404</a>","ieee":"K. Chatterjee, L. De Alfaro, and T. A. Henzinger, “Qualitative concurrent parity games,” <i>ACM Transactions on Computational Logic</i>, vol. 12, no. 4. ACM, 2011.","short":"K. Chatterjee, L. De Alfaro, T.A. Henzinger, ACM Transactions on Computational Logic 12 (2011).","apa":"Chatterjee, K., De Alfaro, L., &#38; Henzinger, T. A. (2011). Qualitative concurrent parity games. <i>ACM Transactions on Computational Logic</i>. ACM. <a href=\"https://doi.org/10.1145/1970398.1970404\">https://doi.org/10.1145/1970398.1970404</a>","ista":"Chatterjee K, De Alfaro L, Henzinger TA. 2011. Qualitative concurrent parity games. ACM Transactions on Computational Logic. 12(4), 28.","mla":"Chatterjee, Krishnendu, et al. “Qualitative Concurrent Parity Games.” <i>ACM Transactions on Computational Logic</i>, vol. 12, no. 4, 28, ACM, 2011, doi:<a href=\"https://doi.org/10.1145/1970398.1970404\">10.1145/1970398.1970404</a>.","chicago":"Chatterjee, Krishnendu, Luca De Alfaro, and Thomas A Henzinger. “Qualitative Concurrent Parity Games.” <i>ACM Transactions on Computational Logic</i>. ACM, 2011. <a href=\"https://doi.org/10.1145/1970398.1970404\">https://doi.org/10.1145/1970398.1970404</a>."},"publisher":"ACM","article_number":"28","month":"07","quality_controlled":"1","status":"public","type":"journal_article","day":"04","author":[{"first_name":"Krishnendu","id":"2E5DCA20-F248-11E8-B48F-1D18A9856A87","full_name":"Chatterjee, Krishnendu","orcid":"0000-0002-4561-241X","last_name":"Chatterjee"},{"first_name":"Luca","last_name":"De Alfaro","full_name":"De Alfaro, Luca"},{"id":"40876CD8-F248-11E8-B48F-1D18A9856A87","full_name":"Henzinger, Thomas A","orcid":"0000−0002−2985−7724","last_name":"Henzinger","first_name":"Thomas A"}],"language":[{"iso":"eng"}],"_id":"3354","corr_author":"1","issue":"4","article_processing_charge":"No"}