Object-Oriented Languages Too Restrictive
Frames, object schema, description logics are popular ontology definition languages
They support definitional axioms of the form:
- R(x) ?
? P(x) ?
{subclass}
- R(x) ?
? [S(x,y) ? P(y)] ?
{value class}
- R(x) ??
? ??y S(x,y) ?
{value cardinality}
They dont support
- N-ary relations and functions
- Standard properties of relations and functions
E.g., transitive, symmetric
- Partial sufficient conditions