A linear-history semantics for languages for distributed programming

A denotational semantics is given for a language for distributed programming based on communication (CSP). The semantics uses both linear sequences of communications to record computations and special states, called 'expectation sets', characterizing potential deadlocks. For any well-formed program segment the semantics is a relation between attainable states and the communication sequences needed to attain these states. In binding two or more processes we match and merge the communication sequences assumed by each process to obtain a sequence and state of the combined process. The approach taken here is distinguished by relatively simple semantic domains and ordering.