Title
Model and Objective Separation with Conditional Lower Bounds: Disjunction is Harder than Conjunction.
Abstract
Given a model of a system and an objective, the model-checking question asks whether the model satisfies the objective. We study polynomial-time problems in two classical models, graphs and Markov Decision Processes (MDPs), with respect to several fundamental ω-regular objectives, e.g., Rabin and Streett objectives. For many of these problems the best-known upper bounds are quadratic or cubic, yet no super-linear lower bounds are known. In this work our contributions are two-fold: First, we present several improved algorithms, and second, we present the first conditional super-linear lower bounds based on widely believed assumptions about the complexity of CNF-SAT and combinatorial Boolean matrix multiplication. A separation result for two models with respect to an objective means a conditional lower bound for one model that is strictly higher than the existing upper bound for the other model, and similarly for two objectives with respect to a model. Our results establish the following separation results: (1) A separation of models (graphs and MDPs) for disjunctive queries of reachability and Büchi objectives. (2) Two kinds of separations of objectives, both for graphs and MDPs, namely, (2a) the separation of dual objectives such as Streett/Rabin objectives, and (2b) the separation of conjunction and disjunction of multiple objectives of the same type such as safety, Büchi, and coBüchi. In summary, our results establish the first model and objective separation results for graphs and MDPs for various classical ω-regular objectives. Quite strikingly, we establish conditional lower bounds for the disjunction of objectives that are strictly higher than the existing upper bounds for the conjunction of the same objectives.
Year
DOI
Venue
2016
10.1145/2933575.2935304
LICS
Keywords
DocType
Volume
Conditional lower bounds, Graph algorithms, Markov Decision processes, Model checking
Conference
abs/1602.02670
ISSN
ISBN
Citations 
1043-6871
978-1-4503-4391-6
3
PageRank 
References 
Authors
0.38
37
4
Name
Order
Citations
PageRank
Krishnendu Chatterjee12179162.09
Wolfgang Dvorák227124.57
Monika Rauch Henzinger34307481.86
Veronika Loitzenbauer4325.08