Parameterized verification through view abstraction

We present a simple and efficient framework for automatic verification of systems with a parametric number of communicating processes. The processes may be organized in various topologies such as words, multisets, rings, or trees. Our method needs to inspect only a small number of processes in order to show correctness of the whole system. It relies on an abstraction function that views the system from the perspective of a fixed number of processes. The abstraction is used during the verification procedure in order to dynamically detect cut-off points beyond which the search of the state space need not continue. We show that the method is complete for a large class of well quasi-ordered systems including Petri nets. Our experimentation on a variety of benchmarks demonstrate that the method is highly efficient and that it works well even for classes of systems with undecidable verification problems. In particular, the method handles the fine-grained and full version of Szymanski’s mutual exclusion protocol, whose correctness, to the best of our knowledge, has not been proven automatically by any other existing methods.