Codifying the Differencing Technique into Formal Transformation Rules over CIP-L

Abstract

Program development by transformations means (cf. [2]) the stepwise development of a program P by writing a sequence P1, P2, ... of more and more detailed versions. Every individual transition from a version Pi to a version Pi+1 is done according to a formal transformation rule. By construction, it is guaranteed that P satisfies the initial specification P1. A further benefit of the transformational approach is that general programming knowledge and techniques are codified into formal rules which may be re-used for whole classes of problems.