Abstract

The paper develops the approach to testing considered in [1]. A formal model of test interaction of the most general type and reduction-type conformance are proposed for which there is hardly any dependence between errors. It is shown that many known types of conformance in various interaction semantics are particular cases of this general model. The paper is devoted to the problem of dependence between errors defined by specification and to the related problem of optimization of tests. There is dependence between errors if there exists a strict subset of errors such that any nonconformal implementation (i.e., implementation that contains some error) contains an error from this subset. Accordingly, it is sufficient that the tests detect errors only from this subset. In the general model proposed, the dependence between errors may arise when one chooses, as a class of implementations under test, some strict subset of the class of all implementations. Partial interaction semantics and/or various implementation hypotheses (in particular, a safety hypothesis) precisely suggest that an implementation under test is not arbitrary but belongs to some subclass of (safe) implementations.