Title
Conditionally Optimal Algorithms for Generalized Büchi Games.
Abstract
Games on graphs provide the appropriate framework to study several central problems in computer science, such as verification and synthesis of reactive systems. One of the most basic objectives for games on graphs is the liveness (or Buchi) objective that given a target set of vertices requires that some vertex in the target set is visited infinitely often. We study generalized Buchi objectives (i.e., conjunction of liveness objectives), and implications between two generalized Buchi objectives (known as GR(1) objectives), that arise in numerous applications in computer-aided verification. We present improved algorithms and conditional super-linear lower bounds based on widely believed assumptions about the complexity of (A1) combinatorial Boolean matrix multiplication and (A2) CNF-SAT. We consider graph games with n vertices, m edges, and generalized Buchi objectives with k conjunctions. First, we present an algorithm with running time O(k*n^2), improving the previously known O(k*n*m) and O(k^2*n^2) worst-case bounds. Our algorithm is optimal for dense graphs under (A1). Second, we show that the basic algorithm for the problem is optimal for sparse graphs when the target sets have constant size under (A2). Finally, we consider GR(1) objectives, with k_1 conjunctions in the antecedent and k_2 conjunctions in the consequent, and present an O(k_1 k_2 n^{2.5})-time algorithm, improving the previously known O(k_1*k_2*n*m)-time algorithm for m u003e n^{1.5}.
Year
DOI
Venue
2016
10.4230/LIPIcs.MFCS.2016.25
MFCS
DocType
Volume
Citations 
Conference
abs/1607.05850
0
PageRank 
References 
Authors
0.34
0
4
Name
Order
Citations
PageRank
Krishnendu Chatterjee12179162.09
Wolfgang Dvorák227124.57
Monika Rauch Henzinger34307481.86
Veronika Loitzenbauer4325.08