Changing system interfaces consistently: A new refinement strategy for CSP parallel to B
This paper is concerned with event refinement in the context of CSP parallel to B. Our motivation to include this notion within the CSP parallel to B framework is the desire to increase flexibility in the refinement process. This approach provides the ability to change the events of CSP processes and B machines when refining a system. Notions of refinement based on traces and on traces/divergences allow abstract events to be refined by sequences of concrete events. A complementary notion of refinement between B machines is also proposed, yielding compositionality results for refinement of CSP parallel to B controlled components. The paper also introduces a notion of I/O refinement into our event refinement framework. (C) 2010 Elsevier B.V. All rights reserved.
csp parallel to b action refinement interface refinement integrating formal methods