Parsing and Validation of full CSP-M Specifications using Haskell and Prolog (Abstract)

CSP is a process algebra defined by Hoare. The first semantics associated with CSP was a denotational semantics in terms of traces, failures and divergences. Later an operational semantics was added [7]. CSP has been applied in many applications, notably for security protocols [6]. The most widely used tools today are fdr [2] and ProBE [3]. These tools use a syntax called machine readable CSP (CSP-M) which is the combination of Core-CSP with a rudimentary functional language. In earlier work we presented CIA [4] a CSP parser and interpreter that supported full Core-CSP and some of the CSP-M extensions. CIA is written in Prolog which made it easy to integrate into the ProB animator and model checker [5], making it the first tool for model-checking combined CSP and B specifications [1]. Our new work is motivated by an industrial application which demands support for full CSP-M syntax, linked with B specifications. Furthermore, an important requirement of our industrial partner was compatibility with the FDR and Probe tools, while at the same time fixing some shortcomings (e.g., the fact that the main process as well as all of its subprocesses in isolation have to be finite state) and obvious bugs of those tools. This is challenging as the semantics of CSP-M is more or less implicitly defined by its implementations in FDR and ProBe. Although, Scattergood [8] describes a formal semantics of CSP-M, there still is a considerable gap between this formal semantics and what is implemented in FDR and ProBE. Other motivations for our re-implementation of CSP-M are for example the desire to: