F. Ipate, T. Balanescu, P. Kefalas, M. Holcombe, G. Eleftherakis
A new Model of Communicating Stream X-machine Systems

Abstract.
One approach to formally specifying a system is to use a form of extended finite state machine called a stream X-machine. Several models of communicating stream X-machines have been devised, either for synchronous and asynchronous communication. One major problem with all these models is that they deviate from the original definition of a stream X-machine. This cause the existing stream X-machine theory or testing methods to be inapplicable for such models.
This paper devises a new model of communicating stream X-machine systems.
Unlike previous models, the communicating stream X-machines used by this model conform to the standard definition of a stream X-machine, so all theoretical results and test generation methods developed for stream X-machines will also apply to this new model.