Guarded commands, nondeterminacy and formal derivation of programs

Abstract

So-called “guarded commands” are introduced as a building block for alternative and repetitive constructs that allow nondeterministic program components for which at least the activity evoked, but possibly even the final state, is not necessarily uniquely determined by the initial state. For the formal derivation of programs expressed in terms of these constructs, a calculus will be be shown.

References

1. 1 Hoare, C.A.R. An axiomatic basis for computer programming. Comm. ACM 12, 10 (Oct. 1969), 576-583.
2. 2 Naur, Peter (Ed.). Report on the algorithmic language ALGOL 60. Comm. ACM 3, (May 1960), 299-314.

Index Terms

• Software and its engineering

  • Software notations and tools

    • Formal language definitions

      • Semantics

    • General programming languages

      • Language types

  • Software organization and properties

    • Software functional properties

      • Correctness

• Theory of computation

  • Logic

    • Proof theory

  • Models of computation

  • Semantics and reasoning

    • Program semantics