Convergence Verification: From Shared Memory to Partially Synchronous Systems

Verification of partially synchronous distributed systems is difficult because of inherent concurrency and the potentially large state space of the channels. This paper identifies a subclass of such systems for which convergence properties can be verified based on the proof of convergence for the corresponding discrete-time shared state system. The proof technique extends to a class of partially synchronous systems in which an agent's state also evolves continuously over time. The proof technique has been formalized in the PVS interface for timed I/O automata and applied to verify convergence of a mobile agent pattern formation algorithm.