FORMAL DEFINITION OF A CONCEPTUAL LANGUAGE FOR THE DESCRIPTION AND MANIPULATION OF INFORMATION MODELS

Conceptual data modelling techniques aim at the representation of data at a high level of abstraction. This implies that conceptual data modelling techniques should not only be capable of naturally representing complex structures, but also the rules (constraints) that must hold for these structures. Contemporary data modelling techniques, however, do not provide a language, which on the one hand has a formal semantics and on the other hand leads to natural looking expressions, for formulating these constraints. In this paper such a language is defined for an existing data modelling technique (PSM), which is a generalisation of object-role models (such as ER or NIAM). In this language not only constraints, but also queries and updates can be expressed on a conceptual level.