*2.7. IRRHEM Instances*

The use of ontology will depend on the ability to reason about individuals [26]. To achieve this in a beneficial manner, it is necessary to have a mechanism for describing the classes to which individuals belong and the properties they inherit due to their membership in these classes. We can always assert specific properties about individuals, but the great strength of ontologies lies in class-based reasoning. Finally, the extension of the class is the set of individual members of a class (Table 4).

**Table 4.** Some examples for IRRHEM individuals (instances).

