Assume-Guarantee Verification for Distributed Systems with Local Specifications

We investigate assume-guarantee reasoning for global specifications consisting of conjunctions of local specifications. We present a sound and complete assume-guarantee rule that permits reasoning about individual modules for local specifications and draws conclusions about global specifications of distributed systems. We illustrate our approach with an example from the field of network congestion control, where different agents are responsible for controlling packet flow across a shared infrastructure. In this context, we derive a sound assume-guarantee rule for system stability, and show that this rule is valuable to reason about any number of agents, any initial flow configuration, and any topology of bounded degree.