Model checking cooperation, knowledge, and time—a case study

Abstract

Alternating-time Temporal Logic (ATL) is a logic developed by Alur, Henzinger, and Kupferman for reasoning about coalitional powers in multiagent systems. Since what agents can achieve in a specific state will in general depend on the knowledge they have in that state, in an earlier paper we proposed Alternating-time Temporal Epistemic Logic (ATEL), an epistemic extension to ATL which is interpreted over Alternating-time Temporal Epistemic Transition Systems. The logic ATEL shares with its ancestor ATL the property that its model checking problem is tractable. However, while model checkers have been implemented for ATL, no model checker yet exists for ATEL, or indeed for epistemic logics in general. The aim of this paper is to demonstrate, using the alternating bit protocol as a detailed case study, how existing model checkers for ATL can be deployed to verify epistemic properties.