Program Comprehension with the Reenement Calculus Extended Abstracttdraft

Program comprehension is an important component of many software development activities, including teaching, debugging, maintenance, reuse and reengineering. This has lead to a number of di erent approaches to developing software tools to aid in program comprehension. In some cases, the aim is to present a program and/or its behaviour in a form that helps a user to understand its structure and/or behaviour. In other cases, the aim is to construct a description of the program in a more convenient or more intelligible form. This may be a better structured or more abstract version of the program, a natural language description or a formal speci cation. The system might attempt to construct this description automatically, usually using some form of heuristic/AI techniques, or might assist a user in constructing this description interactively. The work presented in this paper has elements of several of these approaches.