Process Traces with the Option Operation

摘要

We introduced process traces (ptraces) as a modification of Mazurkiewicz's theory of traces. We showed that ptraces and their corresponding P-expressions more adequately describe concurrent processes. In this paper, we introduce an extension to P-expressions by adding an Option operation. We show the applications as well as the properties of the new operation. We also show that adding the new operation makes P-expressions more powerful and more convenient to describe concurrent systems faithfully.