Title
Counterexample Explanation By Learning Small Strategies In Markov Decision Processes
Abstract
For deterministic systems, a counterexample to a property can simply be an error trace, whereas counterexamples in probabilistic systems are necessarily more complex. For instance, a set of erroneous traces with a sufficient cumulative probability mass can be used. Since these are too large objects to understand and manipulate, compact representations such as subchains have been considered. In the case of probabilistic systems with non-determinism, the situation is even more complex. While a subchain for a given strategy (or scheduler, resolving non-determinism) is a straightforward choice, we take a different approach. Instead, we focus on the strategy itself, and extract the most important decisions it makes, and present its succinct representation.The key tools we employ to achieve this are (1) introducing a concept of importance of a state w.r.t. the strategy, and (2) learning using decision trees. There are three main consequent advantages of our approach. Firstly, it exploits the quantitative information on states, stressing the more important decisions. Secondly, it leads to a greater variability and degree of freedom in representing the strategies. Thirdly, the representation uses a self-explanatory data structure. In summary, our approach produces more succinct and more explainable strategies, as opposed to e.g. binary decision diagrams. Finally, our experimental results show that we can extract several rules describing the strategy even for very large systems that do not fit in memory, and based on the rules explain the erroneous behaviour.
Year
DOI
Venue
2015
10.1007/978-3-319-21690-4_10
COMPUTER AIDED VERIFICATION, PT I
Field
DocType
Volume
Decision tree,Determinism,Computer science,Binary decision diagram,Markov decision process,Algorithm,Theoretical computer science,Cumulative distribution function,Artificial intelligence,Counterexample,Probabilistic logic
Journal
9206
ISSN
Citations 
PageRank 
0302-9743
3
0.36
References 
Authors
46
5
Name
Order
Citations
PageRank
Tomás Brázdil116116.23
Krishnendu Chatterjee22179162.09
Martin Chmelik314610.34
Andreas Fellner430.36
Jan Kretínský515916.02