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Debugging is commonly understood as finding and fixing the cause of a problem. But what does “cause” mean? How can we find causes? How can we prove that a cause is a cause—or even “the” cause? This paper defines common terms in debugging, highlights the principal techniques, their capabilities and limitations.

In this paper, an approach to synthesize correct programs from specifications is presented. The idea is to extract code from definitions appearing in statements which have been mechanically proved with the help of a proof assistant. This approach has been found when proving the correctness of certain Computer Algebra programs (for Algebraic Topology) by using the Isabelle proof assistant. To ea...

One goal of this paper is to review efforts that attempt to provide tools for evaluating computer programs in general and educational computer programs in particular. These tools include open tools and closed tools in the form of ‘forms’ which in turn include an online form which gives the score for the computer program which you evaluate, depending on your own evaluation. Another goal is to re...

Over the past decade, ontology research has investigated the field of computer programs. This work has aimed at defining conceptual descriptions of the programs so as to master their design and use. Unfortunately, these efforts have only been partially successful. In this paper, we present the basis of a Core Ontology of Programs and Software (COPS) which integrates the field’s main concepts. B...

The paper analyzes the author’s experience with modifying large, real-world programs written by other programmers. It finds that Brooks’ domain and programming knowledge based hypothesis-test-refine paradigm explains the author’s approach to understanding programs and the differences in performance in comparison with his students. Zvegintov’s 9–step process of change is found to be a good first...

Increasing work loads, changes in the nature of data obtained from biopsies, and the use of laboratory statistics in determining financial provision for pathological services combine to enhance the value of computer generated results and indexing in histopathology. The system described here depends on an indexed file system using the Basic Plus-2 language with a PDP-11 computer and SNOP. Error ...

-4utomatic differentiation (AD) is a methodology for developing sensitivity-enhanced versions of arbitrary computer programs. In this paper, we provide some background information on AD and address some frequently asked questions. We introduce the ADIFOR and ADIC tools for the automatic differentiation of Fortran 77 and ANSI-C programs, respectively, and give an example of applying ADIFOR in th...

A different view on software complexity based on long range correlation is presented in this paper. Four different methods are first proposed and then used in the analysis of twenty FORTRAN programs. All methods being used indicate the presence of long range correlations, but every method gives different results. The presence of long range correlations denotes that we can in fact regard the com...

Small problems in computer algebra can be done with moderate time and storage. However, even simply stated problems of medium size can be very expensive to compute. Many such problems run out of storage or take excessive time. Large problems, if they can be done at all, can take hours. As in many other fields, we run into the question as to what is the most economical way to obtain raw processi...