The formal specification of ORN semantics

Object Relationship Notation (ORN) is a declarative scheme that permits a variety of common types of relationships to be conveniently defined to a Database Management System (DBMS), thereby allowing the DBMS to automatically enforce their semantics. Though first proposed for object DBMSs, ORN is applicable to any data model that represents binary entity-relationships or to any DBMS that implements them. In this paper, we first describe ORN semantics informally as has been done in previous papers. We then provide a formal specification of these semantics using the Z-notation. Specifying ORN semantics via formal methods gives ORN a solid mathematical foundation. The semantics are defined in the context of an abstract database of sets and relations in a recursive manner that is precise, unambiguous, and noncircular. q 2000 Elsevier Science B.V. All rights reserved.