Sat-based Veriication without State Space Traversal

Binary Decision Diagrams (BDDs) have dominated the area of symbolic model checking for the past decade. Recently, the use of satissability (SAT) solvers has emerged as an interesting complement to BDDs. SAT-based methods are capable of coping with some of the systems that BDDs are unable to handle. The most challenging problem that has to be solved in order to adapt standard symbolic model checking to SAT-solvers is the boolean quan-tiication necessary for traversing the state space. A possible approach to extending the applicability of SAT-based model checkers is therefore to reduce the amount of traversal. In this paper, we investigate a BDD-based veriication algorithm due to van Eijk. Van Eijk's algorithm tries to compute information that is suucient to prove a given safety property directly. When this is not possible, the computed information can be used to reduce the amount of traversal needed by standard model checking algorithms. We convert van Eijk's algorithm to use a SAT-solver instead of BDDs. We also make a number of improvements to the original algorithm, such as combining it with recently developed variants of induction. The result is a collection of substantially strengthened and complete veriication methods that do not require state space traversal.