Verification of Population Ring Protocols in PAT

The population protocol model has emerged as an elegant paradigm for describing mobile ad hoc networks, consisting of a number of nodes that interact with each other to carry out a computation. One essential property of self-stabilizing population protocols is that all nodes must eventually converge to the correct output value, with respect to all possible initial configurations. It has been shown that fairness constraints play a crucial role in designing population protocols. The Process Analysis Toolkit (PAT) has been developed to perform verifications under different fairness constraints efficiently. In particular, it can handle global fairness, which is required for the correctness of most of population protocols. It is an ideal candidate for automatically verifying population protocols. In this paper, we summarize our latest empirical evaluation of PAT on a set of self-stabilizing population protocols for ring networks. We report one previously unknown bug in a protocol for leader election identified using PAT.