Using counter example guided abstraction refinement to find complex bugs

In this paper, we present a method for finding failure traces for safety properties that are out of reach for traditional approaches to counter example generation. We do this by guiding Bounded Model Checking (BMC) with information gathered from counter example guided abstraction refine-ment. Unlike previously described approaches based on re-constructing abstract counter examples on the concrete ma-chines, we do not limit ourselves to search for failures of the same length as the current abstract counterexample. We also describe a combination of previously known methods for choosing registers to include in the abstraction that we have found works very well together with our technique for finding failures. Our experimental results show that the re-sulting method can find counter examples that are out of range for both standard BMC and two previously published approaches to abstraction-guided BMC. 1.