The representation of semantic constraints in conceptual graph systems

Abstract

The conceptual graph formalism is both simple and expressive. It offers great potential as a modeling formalism for developing information systems. In fact, its potential was recognized by the ANSI X3H4.6 committee, which recommended its adoption as a standard for such modeling tasks [1]. However, it lacks the modeling capabilities required to represent a wide range of semantic constraints, even though this is a vital characteristic of any useful modeling formalism. In this article, we propose a representation based on generalization hierarchies as defined [15], which allows most semantic constraints found in database literature to be: 1) represented in a unified framework, 2) enforced at all times, 3) subject to a minimum of resources, and 4) compared with one another in terms of their scope. Also, this paper shows that no cg system which allows the generalization of concepts, such as with maximal type expansion, is sound without the explicit representation of certain semantic constraints.