Effectively Eliminating Auxiliaries

Abstract

International audienceAuxiliary variables are used in the intermediate steps of a correctness proof to store additional information about the computation. We investigate for which classes of programs auxiliary variables can be avoided in the associated proof system, and give effective translations of proofs whenever this is the case

Fifty years of Hoare’s logic

“…The most extensive analysis of these matters was provided in [dGR16] that clarified and extended initial results of [Kle98] and [Kle99]. The authors of [dGR16] showed that the AUXILIARY VARIABLES rule is a derived rule both in the proof system H and in a proof system for parameterless recursive procedures, which means that it can be eliminated from any proof that uses it. In the case of disjoint parallel programs the authors showed that this rule can be replaced by the simpler ∃-INTRODUCTION rule discussed in Subsection 5.1.…”