Technical Report Number
Verifying correctness properties of parameterized systems is a long-standing problem. The challenge lies in the lack of guarantee that the property is satisfied for all instances of the parameterized system. Existing work on addressing this challenge aims to reduce this problem to checking the properties on smaller systems with a bound on the parameter referred to as the cut-off. A property satisfied on the system with the cut-off ensures that it is satisfied for systems with any larger parameter. The major problem with these techniques is that they only work for certain classes of systems with specific communication topology such as ring topology, thus leaving other interesting classes of systems unverified. We contribute an automated technique for finding the cut-off of the parameterized system that works for systems defined with any topology. Given the specification and the topology of the system, our technique is able to automatically generate the cut-off specific to this system. We prove the soundness of our technique and demonstrate its effectiveness and practicality by applying it to several canonical examples where in some cases, our technique obtains smaller cut-off values than those presented in the existing literature.