Designing a dynamic integrity constraint checker with nonmonotonic logic

The authors report on the design of a dynamic integrity constraint checker with a nonmonotonic interval logic (IL). Central to this logic is the inclusion of the unless operator which captures the nonmonotonicity of dynamic integrity constraints over temporal intervals. IL is embedded in the Ada/ISL Interval Specification Language which has been utilized in the design of the Icarus Integrity System. In this system, the answer to a query depends on the availability of an explicit body of knowledge (knowledge base) about the integrity of data items contained in the query. The principal inference mechanism in this system is the refutation of faulty beliefs about data based on partial information and intuition, with respect to facts in the knowledge base. A technique for the verification of the Icarus kernel is presented. A family of assertions about the completeness, correctness, and confidence integrity characteristics about data is included in the integrity model