The Rôle of Normalisation in Testing from Structured Algebraic Specifications

This paper investigates the use of normalisation for testing from structured algebraic specifications. The intention is to compute a related, possibly simpler, specification, namely the normal form, and use it to test programs whenever testing from the original specification is too complex or undecidable in the sense that a procedure for interpreting the results cannot be given, the so-called oracle problem. We focus on specifications with testing interface, where test suites are defined at specification level, with axioms expressed in first-order logic. Three normal forms are presented for coping with some obstacles encountered when testing from structured specifications. Furthermore, it turns out that, under certain circumstances, tests based on normal forms can be more rigorous than tests based on the original specification.