RELATIONAL DIVISION IN INFORMATION MANAGEMENT

We present a unified framework for the management of stored data, deci sion models, and assertions in two-valued logic, based on the algebra of relations and on the operation of relational division. This powerfu l operation was developed in the context of stored data, and it also h as limited applicability to models and assertions. The strength and we akness of division is that it allows universal quantification of certa in queries on partitioned relations. We extend this concept by introdu cing a new operation, relational pseudodivision, which replaces univer sal with existential quantification and thus enlarges the set of avail able partitioning operations.