Since 1989, numerous works about declarative modelling have been done. Now, it Cur- rently, it is necessary to make general methods based on those previous studies evolve. New tools to help in building declarative modelers must be proposed. We propose a new formalism based on the fuzzy sets. This formalism is a synthesis and unification of existent works. It also brings new elements as fuzzy logic, linguistic manage- ment of the negation, etc. We have particularly studied the simplest type of property : the elementary property. Using the notion basic properties, fuzzy operators and modifiers, we describe a method to processing the semantic of an elementary property. We propose also an original processing of its negation. Rather than to use the usual logical negation, we have been interested in a management based on linguistic notions. Finally, we present solutions of processing for the other properties. However, these solutions are not truly satisfactory. Most of projects in declarative modeling implement similar techniques. From these works and the fuzzy formalism, we have developed the CordiFormes project, a programming plat- form and a set of tools to help the creation of future declarative modelers. Its characteristics are the simplicity, the flexibility of programming, the efficiency, the extendibility, the reus- ability and the quick modeler's prototyping. CordiFormes proposes three levels of tools : the kernel level containing all basic structures and all basic algorithms, the interface level pro- posing dialogues and interface components and finally the application level to produce rap- idly a first basic modeler. Three applications have allowed to validate the formalism and tools of the platform.
