Ontology definition in OIL
An OIL ontology consists of a set of definitions:
import: a list of references to other OIL modules that are to be included in this ontology. Each reference consists of a URI specifying where the module is to be imported from, e.g., “http://www.ontology.com/animals/jungle.onto”.
rule-base: a list of rules that apply to the ontology. At present , the structure of these rules are not defined.
definition: zero or more class definition (class-def) and slot definition (slot-def).