A very simple model, the Predicator Model, is introduced in a rigid formal way. We introduce the concept of population as an instantiation of an information structure. A primitive manipulation language is defined in the style of Relational Algebra. Well-known types of constraints are defined in terms of the algebra introduced, as restrictions on populations. They are given more expressive power than is usually the case.
Constraints are of central importance for identification purposes.
P. van der Weide. Semantics and verification of object-role models. P. van der Weide. Semantics and verification of object-role models. The NIAM case study - Sernadas, Fiadeiro et al.