Analysis of Communicating Infinite State Machines Using Lattice Automata Tristan Le Gall & Bertrand Jeannet

Communication protocols can be formally described by the Communicating Finite-State Machines (CFSM) model. This model is expressive, but not expressive enough to deal with complex protocols that involve structured messages encapsulating integers or lists of integers. This is the reason why we propose an extension of this model : the Symbolic Communicating Machines (SCM). We also propose an approximate reachability analysis method, based on lattice automata. Lattice automata are finite automata, the transitions of which are labeled with elements of an atomic lattice. We tackle the problem of the determinization as well as the definition of a widening operator for these automata. We also show that lattice automata are useful for the interprocedural analysis. Key-words: Asynchronous systems, Abstract interpretation, Verification of infinite systems, FIFO channels, Lattice automata, Interpocedural analysis