Title
On the complexity of the equivalence problem for probabilistic automata
Abstract
Deciding equivalence of probabilistic automata is a key problem for establishing various behavioural and anonymity properties of probabilistic systems. In recent experiments a randomised equivalence test based on polynomial identity testing outperformed deterministic algorithms. In this paper we show that polynomial identity testing yields efficient algorithms for various generalisations of the equivalence problem. First, we provide a randomized NC procedure that also outputs a counterexample trace in case of inequivalence. Second, we consider equivalence of probabilistic cost automata. In these automata transitions are labelled with integer costs and each word is associated with a distribution on costs, corresponding to the cumulative costs of the accepting runs on that word. Two automata are equivalent if they induce the same cost distributions on each input word. We show that equivalence can be checked in randomised polynomial time. Finally we show that the equivalence problem for probabilistic visibly pushdown automata is logspace equivalent to the problem of whether a polynomial represented by an arithmetic circuit is identically zero.
Year
DOI
Venue
2012
10.1007/978-3-642-28729-9_31
FOSSACS'12 Proceedings of the 15th international conference on Foundations of Software Science and Computational Structures
Keywords
DocType
Volume
probabilistic cost automaton,randomised equivalence test,key problem,equivalence problem,probabilistic system,automata transition,probabilistic automaton,polynomial identity testing,randomised polynomial time,polynomial identity testing yield
Conference
abs/1112.4644
ISSN
Citations 
PageRank 
0302-9743
6
0.50
References 
Authors
28
5
Name
Order
Citations
PageRank
Stefan Kiefer134536.87
Andrzej S. Murawski232432.93
Joël Ouaknine3148199.25
Björn Wachter432620.09
James Worrell5104081.17