Pushdown Specifications

Traditionally, model checking is applied to finite-state systems and regular specifications. While researchers have successfully extended the applicability of model checking to infinite-state systems, almost all existing work still consider regular specification formalisms. There are, however, many interesting non-regular properties one would like to model check.

In this paper we study model checking of pushdown specifications. Our specification formalism is nondeterministic pushdown parity tree automata (PD-NPT). We show that the model-checking problem for regular systems and PD-NPT specifications can be solved in time exponential in the system and the specification. Our model-checking algorithm involves a new solution to the nonemptiness problem of nondeterministic pushdown tree automata, where we improve the best known upper bound from a triple-exponential to a single exponential. We also consider the model-checking problem for context-free systems and PD-NPT specifications and show that it is undecidable.

@inproceedings{KPV02a,
         author = "O. Kupferman and N. Piterman and M. Vardi",
         title = "Pushdown Specifications",
         booktitle = "9th International Conference on Logic for Programming Artificial Intelligence and Reasoning",
         series = "Lecture Notes in Artificial Inteligence", month = "October",
         year = 2002
}

PDF