A Process Algebraic Method for the Speci cationand

This chapter describes a timed process algebra, called ACSR, which supports time-consuming actions and instantaneous events. Actions model the usage of shared resources and the passage of time, whereas events allow synchronization between processes. To be able to specify real-time systems accurately, ACSR supports static priorities that can be used to arbitrate between actions competing for shared resources and between events that are ready for synchronization. ACSR also ooers diierent notions of equivalence that can be used to verify that two processes behave the same. ACSR is illustrated through the speciication and analysis of a scheduler example, as well as three variants of the railroad crossing problem.