Program Development as a Formal Activity

Abstract

A methodology has been outlined of program development by transformations. The Warshall algorithm is developed by the methodology to illustrate the methodology. The transition from one program to another is a transformation. Program transformation relations must be reflexive to be valid, and transitive to allow successive application of several transformations. Transformational semantics are used to prove the correctness of transformation rules. Specification techniques and abstract data types allow the description of the language to be modularized as a hierarchy of types. The data structures in the hierarchy provide an algebraic frame for handling data types, transformation rules, and semantics.