Symbolic Model Checking of Extended Finite State Machines with Linear Constraints over Integer Variables

摘要

We propose a symbolic model checking algorithm for a class of extended finite state machines equipped with integer variables (FSM/int). An FSM/int has several constraints on variable assignments, such as a variable of FSM/int keeps its value until the control visits at the definition transition and new value is fed via external input. Our model checking algorithm verifies whether an FSM/int satisfies a property described in CTL-like expressions over integer variables. We have implemented a model checker, and verified that blackjack dealer circuits and a packet multiplex protocol satisfy some designated properties. We have found that the verification of systems with 100 states and 10 integer variables can be carried out in a few seconds in most cases (in the worst case, a few minutes).