Deductive Entity Relationship Modeling

An entity relationship oriented model, that includes the notion of class, together with different types of assertions on classes, is presented. The assertions are used to model IS-A and disjointness relations both between entities and between relationships, part-of relations between entities and relationships, mandatory participation of an entity in a relationship, and interdependencies between the projections of relationships. The semantics of the model are defined in terms of first-order logic, and a sound and complete inference algorithm for such a model is presented. The algorithm is shown to have polynomial time complexity in the case where interdependencies on the projections of relationships are not taken into account. It is suggested that the model and the associated inference capabilities provide a suitable formal basis for designing an effective environment supporting conceptual modeling.