Complex-Prolog: A Logic Database Language for Handling Complex Objects

The logic language paradigm represents a natural extension of relational databases. However, one of its limitations is the lack of suitable data abstraction mechanisms for modeling complex objects. This paper describes Complex-Prolog, a logic database language that provides facilities for data abstraction, notably, the notions of object identity, class and inheritance. This language was designed as an attempt to integrate concepts from logic programming and semantic data models. A formal definition of Complex-Prolog, interspersed with a number of examples, is given. The paper concludes with a description of its implementation.