**5.2 Properties axioms**

The properties axioms define relationship between classes in the ontology. They are also used to relate an object to other via topological relations. Actually, we found four major object properties axioms in the top level ontology which have their specialized properties for the specialized activities, Fig. 7, DC:hastopologicRelation, Alg:isDeseignedFor, Geom:hasGeometry, Charac:hasCharacteristics.

Fig. 7. Ontology general schema overview.
