From Programs to Z Specifications

Abstract

Universal techniques for transforming code from a typical procedural language to Z-like specifications will be discussed first; the latter make good starting points for the post hoc validation of programs which lack formal documentation. We prove properties of classes of programs, before we move on to discuss the further set of techniques we use to prove properties of individual programs. In the foundational work, we provide a concise algebraic language and axioms based on the simple mathematical theory of monads, and show that it is sufficiently expressive. We then give practical validation techniques which extend these transformations and provide several examples of such heuristically driven program validations.