SCDBR: An Automated Reasoner for Specifications of Database Updates

In this paper we describe SCDBR, a system that is able to reason automatically from specifications of database updates written in the situation calculus, a first–order language originally proposed by John McCarthy for reasoning about actions and change. The specifications handledby the system are written in the formalism proposed by Ray Reiter for solving the frame problem that appears when one expresses the effects on the database predicates of the execution of atomic transactions.SCDBR is written in PROLOG, and can solve several reasoning tasks, among others,it is able to derive the final specification from effect axioms, to answerqueries to virtually updated databases, to check legality of transactions,to prove integrity constraints from the specification, to modify thespecification in order to embed a desired integrity constraint, and to answer historical queries. For some of these tasks SCDBR can call othersystems, like relational database systems, automated theorem provers, andconstraint solvers.