Semantics for Specifying Real-Time Systems

Real-time programs are the least well understood of concurrent programs: apart from being subject to all the usual problems associated with concurrency and communication they must interact with a variety of agents’ at points in the execution that have a specified ordering relation with time. So, for example, the familiar partial order over the execution of the statements of a concurrent program must be made more elaborate to accommodate time-ordering, and this requires a semantics that can account for programs whose execution may be constrained by limitations on the availability of resources.