对Wirth一个不变式的修正

Correction of One of the Wirth Invariants

Wirth在《算法 +数据结构 =程序》一书中关于“对半检索”程序中给出了一个不变式 ,但该不变式是不完善的 .本文对此予以了修正 ,并通过一系列定理及其证明进行了完整的论证 .在论证过程中 ,也揭示出程序作为一种对象 ,其整体的一些性质 .程序的这些特性 ,在一般测试时未必能被认识 .因而程序中的“不变式”及对“不变式”的论证 。

An invariant given by N.Wirth in Algorithm+Datastructure=Program has been proved more or less inaccurate in “Binary Research” Program. In this paper, the inaccuracy is modified on the basis of related principles. Furthermore, the properties of the complete program as an object are discussed, which are not recognized in general tests.