db_connect: Could not connect to paper db at "wotug@dragon.kent.ac.uk"
db_connect: Could not connect to paper db at "wotug@dragon.kent.ac.uk"
%T Successes and Failures: Extending CSP db_connect: Could not connect to paper db at "wotug@dragon.kent.ac.uk"
%A Adrian E. Lawrence db_connect: Could not connect to paper db at "wotug@dragon.kent.ac.uk"
%E Alan G. Chalmers, Majid Mirmehdi, Henk Muller %B Communicating Process Architectures 2001 %X Standard CSP, timed or untimed, does not include a general treatment of priority, although the PRI ALT constructor is an essential part of occam and hardware compilation languages based upon occam. This is a revised version of the original paper which introduced CSPP, an extension of CSP incorporating priority. CSPP is defined by a novel denotational semantics, Acceptances, based on Successes rather than the usual Failures. The idea is to characterise a process by what it successfully accepts, rather than by what it refuses to do. In the light of experience, it might better have been called \[rs]Responses\[rs]. The original Acceptances was exploratory, and tried to avoid constraining the sorts of systems, particularly circuits, that could be described. Experience has shown that it can be substantially simplified at very little cost. A new notation makes it much easier to follow, especially for the non specialist. This revision of the original introduction presents the simplified CSPP while retaining most of the motivational material. It is intended to have something of a tutorial flavour: three other papers, are more condensed, and deal with more technical matters. But the core semantics is common to all four. CSPP provides a rigorous comprehensible and simple foundation for compositional hardware\-software codesign. HCSP is a further extension which includes extra facilities needed to describe certain circuits. And a further radical extension lifts the usual restrictions of timed CSP, and describes continuous analogue phenomena. CSPP was first presented informally at the Twente WoTUG\-\-20 technical meeting.