How does the IFF represent ontologies?
The IFF represents ontologies with the concepts of theories and logics. An ontology is populated when it contains instance data. Unpopulated ontologies containing only axioms are represented by IFF theories, whereas populated ontologies are represented by IFF logics. An IFF logic has two parts, an IFF theory and an IFF model that satisfies that theory. An IFF model provides for an interpretative semantics, an IFF theory provides for a formal or axiomatic semantics, and an IFF logic provides for a combined, both formal and interpretative, semantics.
