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Kleene under a Demonic Star

  • Jules Desharnais
  • Bernhard Möller
  • Fairouz Tchier
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1816)

Abstract

In relational semantics, the input-output semantics of a program is a relation on its set of states. We generalize this in considering elements of Kleene algebras as semantical values. In a nondeterministic context, the demonic semantics is calculated by considering the worst behavior of the program. In this paper, we concentrate on while loops. Calculating the semantics of a loop is difficult, but showing the correctness of any candidate abstraction is much easier. For deterministic programs, Mills has described a checking method known as the while statement verification rule. A corresponding programming theorem for nondeterministic iterative constructs is proposed, proved and applied to an example. This theorem can be considered as a generalization of the while statement verification rule to nondeterministic loops.

Keywords

while loop demonic semantics relational abstraction verification Kleene algebra rule generalization 

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Copyright information

© Springer-Verlag Berlin Heidelberg 2000

Authors and Affiliations

  • Jules Desharnais
    • 1
  • Bernhard Möller
    • 2
  • Fairouz Tchier
    • 3
  1. 1.Département d’informatiqueUniversité LavalQuébecCanada
  2. 2.Institut für InformatikUniversität AugsburgAugsburgGermany
  3. 3.Mathematics DepartmentKing Saud UniversityRiyadhSaudi Arabia

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