Validating specifications of dynamic systems using automated reasoning techniques

In this paper, we propose a new approach to validating formal specifications of observable behavior of discrete dynamic systems. By observable behavior we mean system behavior as observed by users or other systems in the environment of the system. Validation of a formal specification of an informal domain tries to answer the question whether the specification actually describes the intended domain. This differs from the verification problem, which deals with the correspondence between formal objects, e.g. between a formal specification of a system and an implementation of it. We consider formal specifications of object-oriented dynamic systems that are subject to static and dynamic integrity constraints. To validate that such a specification expresses the intended behavior, we propose to use a tool that can answer reachability queries. In a reachability query we ask whether the system can evolve from one state into another without violating the integrity constraints. If the query is answered positively, the system should exhibit an example path between the states; if the answer is negative, the system should explain why this is so. An example path produced by the tool can be used to produce scenarios for presentations of system behavior, but can also be used as a basis for acceptance testing. In this paper, we discuss the use of planning and theoremproving techniques to answer such queries, and illustrate the use of reachability queries in the context of information system development

Sur la Validité des Schémas de Bases de Données

Les mises a jour (Tun schema de base de donnees peuvent porter sur ses trois Constituante, ( l ) les declarations de structures, (2) les regies de coherence (et de deduction) et (3) les transactions. Ces Constituante doivent verifier certaines proprietes, definissant les Schemas valides. Un Systeme de gestion de Schemas doit pouvoir verifier la validite des sche"mas (independamment de toute extension de la base) et detecter les modifications des Schemas violant les conditions de validite. Dans cet article nous decrivons tout d'abord Papproche que nous avons suivi pour realiser un Systeme de gestion des declarations de structures, premier composant disponible d'un Systeme de gestion de Schemas en cours de developpement. Cette approche fait de la validite de declarations de structures un probleme semblable a la verification des regies de coherence dans une base de donnees. Nous montrons ensuite que la validite des regies (de coherence et de deduction) correspond a une propriete logique plus forte que la consistence, la satisfaisabilite finie. Dans certains cas, cette propriete peut elre detected par des methodes de refutation de preuve automatique de theoremes. Considerant la resolution, sur laquelle s'appuient les procedures de refutation les plus performantes, nous caracterisons les additions necessaires pour etendre une procedure de refutation en une methode complete pour la satisfaisabilite finie. Une telle extension de la resolution est decrite