Model Based Refinement and the Tools of Tomorrow

The ingredients of typical model based development via refinement are re-examined, and some well known frameworks are reviewed in that light, drawing out commonalities and differences. It is observed that alterations in semantics take place de facto due to applications pressures and for other reasons. This leads to a perspective on tools for such methods in which the proof obligations become programmable and/or configurable, permitting easier co-operation between techniques and interaction with an Evidential Tool Bus. This is of intrinsic interest, and also relevant to the Verification Grand Challenge.