Deductive Databases and Knowledge Base Systems.

The following sections describe the research that has been accomplished during the entire grant period form September 1, 1991 to March 31, 1995, with partial support from the Air Force Office of Scientific Research and summarizes the papers, prototype systems and theses produced on the grant. Several major areas will be discussed. These are Cooperative Databases Systems, Combining Knowledge Base Systems, Disjunctive Deduction Databases, Extensions to the Semantics of Logic Programming and Parallel Logic Programming. During the first year of the grant we emphasized theoretical aspects of work in deductive databases and knowledge base systems. During the second year we stressed the development of tools and techniques to transfer the theory into practical systems. During the third year we developed prototype systems and experiments with them. Technological developments were made in Cooperative Database Systems and Disjunctive Deductive Databases. New theoretical developments were achieved in the Semantics of Logic Programming and in Combining Databases.