Intertwined Forward-Backward Reachability Analysis Using Interpolants

In this work we develop a novel SAT-based verification approach which is based on interpolation. The novelty of our approach is in extracting interpolants in both forward and backward manner and exploiting them for an intertwined approximated forward and backward reachability analysis. Our approach is also mostly local and avoids unrolling of the checked model as much as possible. This results in an efficient and complete SAT-based verification algorithm. We implemented our algorithm and compared it with both McMillan’s interpolation-based algorithm and with IC3, on real-life industrial designs as well as on examples from the HWMCC’11 benchmark. In many cases, our algorithm outperformed both methods.