Abstract

If Z specifications are used as requirements specifications then test result evaluation leads to evaluation of schema predicates in states that are reached by the test. For automation of this approach Z operational schemas must be translated into programs that perform schema predicate evaluation. Predicate evaluation is straightforward; expressions are replaced by their values, logical connectives are evaluated using truth-tables, quantifiers and set constructions are evaluated using iteration. In order to exclude infinite iterations while evaluating quantifiers the schema compiler accepts besides finite quantifications only those which can be transformed into finite ones using term-rewriting techniques. These ideas are implemented in a Z predicate compiler.

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