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Pushdown Processes: Games and Model Checking
, 1996
"... Games given by transition graphs of pushdown processes are considered. It is shown that ..."
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Cited by 183 (8 self)
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Games given by transition graphs of pushdown processes are considered. It is shown that
How Much Memory is Needed to Win Infinite Games?
, 1997
"... We consider a class of infinite twoplayer games on finitely coloured graphs. Our main question is: given a winning condition, what is the inherent blowup (additional memory) of the size of the I/O automata realizing winning strategies in games with this condition. This problem is relevant to synth ..."
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Cited by 60 (3 self)
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We consider a class of infinite twoplayer games on finitely coloured graphs. Our main question is: given a winning condition, what is the inherent blowup (additional memory) of the size of the I/O automata realizing winning strategies in games with this condition. This problem is relevant to synthesis of reactive programs and to the theory of automata on infinite objects. We provide matching upper and lower bounds for the size of memory needed by winning strategies in games with a fixed winning condition. We also show that in the general case the LAR (latest appearance record) data structure of Gurevich and Harrington is optimal. Then we propose a more succinct way of representing winning strategies by means of parallel compositions of transition systems. We study the question: which classes of winning conditions admit only polynomialsize blowup of strategies in this representation. 1 Introduction We consider games played on (not necessarily finite) graphs coloured with a finite nu...
Local liveness for compositional modeling of fair reactive systems
 CAV 95: Computeraided Verification, Lecture Notes in Computer Science 939
, 1995
"... Abstract. We argue that the standard constraints on liveness conditions in nonblocking trace modelsmachine closure for closed systems, and receptiveness for open systemsare unnecessarily weak and complex, and that liveness should, instead, be speci ed by augmenting transition systems with acceptan ..."
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Cited by 20 (4 self)
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Abstract. We argue that the standard constraints on liveness conditions in nonblocking trace modelsmachine closure for closed systems, and receptiveness for open systemsare unnecessarily weak and complex, and that liveness should, instead, be speci ed by augmenting transition systems with acceptance conditions that satisfy a locality constraint. First, locality implies machine closure and receptiveness, and thus permits the composition and modular veri cation of live transition systems. Second, while machine closure and receptiveness are based on in nite games, locality is based on repeated nite games, and thus easier to check. Third, no expressive power is lost by the restriction to local liveness conditions. We illustrate the appeal of local liveness using the model of Fair Reactive Systems, a nonblocking trace model of communicating processes. 1
Qualitative Concurrent Parity Games
, 2008
"... We consider 2player games played on a finite state space for an infinite number of rounds. The games are concurrent: in each round, the two players choose their moves independently and simultaneously; the current state and the two moves determine the successor state. We consider ωregular winning c ..."
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Cited by 4 (2 self)
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We consider 2player games played on a finite state space for an infinite number of rounds. The games are concurrent: in each round, the two players choose their moves independently and simultaneously; the current state and the two moves determine the successor state. We consider ωregular winning conditions specified as parity objectives on the resulting infinite state sequence. Both players are allowed to use randomization when choosing their moves. We study the computation of the limitwinning set of states, consisting of the states where the supinf value of the game for player 1 is 1: in other words, a state is limitwinning if player 1 can ensure a probability of winning arbitrarily close to 1. We show that the limitwinning set can be computed in O(n 2m+2) time, where n is the size of the game structure and 2m is the number of parities; membership of a state in the limitwinning set can be decided in NP ∩ coNP. While this complexity is the same as for the simpler class of turnbased 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 turnbased games. This is because concurrent games violate two of the most fundamental properties of turnbased parity games. First, in concurrent games limitwinning strategies require randomization; and second, they require infinite memory.
The Complexity of Learning Branches and Strategies from Queries
 In Proceedings of the Eighth Annual International Symposium on Algorithms and Computation, volume 1350 of LNCS
, 1997
"... . We study the problems of efficiently learning infinite branches for finite state trees and winninig strategies for closed finitestate games using membership, and branch or strategy queries, respectively. We show that generally no efficient branch learning algorithm exists but we provide such algor ..."
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Cited by 1 (1 self)
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. We study the problems of efficiently learning infinite branches for finite state trees and winninig strategies for closed finitestate games using membership, and branch or strategy queries, respectively. We show that generally no efficient branch learning algorithm exists but we provide such algorithms for several natural cases, in particular for deadend free finitestate trees, the class of trees such that the set of infinite branches has positive measure, and several classes of modulo trees. Furthermore, we find a way to apply Angluin's results about the identification of deterministic finite automata from queries, which yields positive and negative strategy learning results, in particular, we show that the class of deadend free closed finitestate games is efficiently strategy learnable from membership and strategy queries. 1 Introduction In [6, 10,13] an inductive inference approach to learning process controllers has been studied. Hereby, the control problem is modeled as a clo...
Pushdown processes: games and model checking (Extended Abstract)
 INFORMATION AND COMPUTATION
, 1996
"... Games given by transition graphs of pushdown processes are considered. It is shown that if there is a winning strategy in such a game then there is a winning strategy which is realized by a pushdown process. This fact turns out to be connected with the model checking problem for pushdown automat ..."
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Games given by transition graphs of pushdown processes are considered. It is shown that if there is a winning strategy in such a game then there is a winning strategy which is realized by a pushdown process. This fact turns out to be connected with the model checking problem for pushdown automata and the propositional µcalculus. It is show that this model checking problem is DEXPTIMEcomplete.