Learning to Verify Safety Properties

We present a novel approach for verifying safety properties of finite state machines communicating over unbounded FIFO channels that is based on applying machine learning techniques. We assume that we are given a model of the system and learn the set of reachable states from a sample set of executions of the system, instead of attempting to iteratively compute the reachable states. The learnt set of reachable states is then used to either prove that the system is safe or to produce a valid execution of the system leading to an unsafe state (i.e., a counterexample). We have implemented this method for verifying FIFO automata in a tool called LEVER that uses a regular language learning algorithm called RPNI. We apply our tool to a few case studies and report our experience with this method. We also demonstrate how this method can be generalized and applied to the verification of other infinite state systems

Interface Generation and Compositional Verification in JavaPathfinder

Abstract. We present a novel algorithm for interface generation of software components. Given a component, our algorithm uses learning techniques to compute a permissive interface representing legal usage of the component. Unlike our previous work, this algorithm does not require knowledge about the component’s environment. Furthermore, in contrast to other related approaches, our algorithm computes permissive interfaces even in the presence of non-determinism in the component. Our algorithm is implemented in the JavaPathfinder model checking framework for UML statechart components. We have also added support for automated assume-guarantee style compositional verification in JavaPathfinder, using component interfaces. We report on the application of the presented approach to the generation of interfaces for flight software components.