Computing

, Volume 22, Issue 3, pp 279–282 | Cite as

Comments on a paper by neuhold and studer

  • P. Pritchard
Short Communication

Abstract

The authors of [5] described their experience in applying Hoare's method of program verification to an existing program. They reported two difficulties. The first was that certain Boolean expressions occurring in conditional or while statements needed to be strengthened to enable verification. This claim is false, and their three putative examples are refuted. The second difficulty was that the program had to be modified to use very restricted forms of jumps and procedures. Re this, we document recent work which enables these restrictions to be lifted.

Bemerkungen zu einer Veröffentlichung von Neuhold und Studer

Zusammenfassung

Die Autoren von [5] berichten über zwei spezielle Probleme bei der Anwendung der Methode von Hoare zur Verifikation eines gegebenen Programmes. Sie behaupten erstens, es sei notwendig, einige Boolesche Ausdrücke zu verschärfen und zweitens, man müsse sich auf bestimmte Formen von Sprunganweisungen und Unterprogrammen beschränken, um einen Korrektheitsbeweis zu ermöglichen. Es wird gezeigt, daß die erste Behauptung nicht zutrifft und sich die zweite Beschränkung auf Grund einiger neuer Arbeiten aufheben läßt.

References

  1. [1]
    Cartwright, R., Oppen, D.: Unrestricted procedure calls in Hoare's logic. ACM Symposium on Principles of Programming Languages, 1978.Google Scholar
  2. [2]
    Cook, S. A.: Soundness and completeness of an axiom system for program verification. SIAM J. Computing7, 70–90 (1978).Google Scholar
  3. [3]
    Ernst, G. W.: Rules of inference for procedure calls. Acta Informatica8, 145–152 (1977).Google Scholar
  4. [4]
    Kowaltowski, T.: Axiomatic approach to side effects and general jumps. Acta Informatica7, 357–360 (1977).Google Scholar
  5. [5]
    Neuhold, E. J., Studer, R.: The use of Hoare's method of program verification for the quicksort algorithm. Computing18, 281–293 (1977).Google Scholar

Copyright information

© Springer-Verlag 1979

Authors and Affiliations

  • P. Pritchard
    • 1
  1. 1.Department of Computer ScienceUniversity of QueenslandBrisbaneAustralia

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