Question

I have problems relating classes (not individuals) in my ontology. I need to know which one
OWL(full-dl-lite) allows to relate classes.
i mean the domain and range of property be http://www.w3.org/2002/07/owl#Class.
Is it possible to do that?
thanks for any hint.

Answer 1

First, forget about the spec at http://www.w3.org/TR/owl-guide/, http://www.w3.org/TR/owl-ref/ and http://www.w3.org/TR/owl-semantics/. The official recommendation for a Web Ontology Language is OWL 2, where the various sublanguages are OWL 2 EL, OWL 2 QL, OWL 2 RL, OWL 2 DL and OWL 2 Full (read about the new features of OWL 2). OWL Lite does not exist anymore and should be forgotten forever.

Second, in OWL (both 1 and 2), it has always been possible to relate classes using annotation properties, like this in Turtle:

# valid in all variants and OWL 1 and OWL 2
:prop  a  owl:AnnotationProperty .
:C1  a  owl:Class .
:C2  a  owl:Class;
     :prop  :C2 .

In OWL 1, it was not possible to define a domain or range for an annotation property but it is now possible in OWL 2:

# works in all variants of OWL 2
:prop  a  owl:AnnotationProperty;
       rdfs:domain  owl:Class;
       rdfs:range  owl:Class .

Your other option is to rely on the notion of “punning”, that is, using the IRI of a class for an individual, like so:

# works in all variants of OWL 2
:prop  a  owl:ObjectProperty .
:C1  a  owl:Class .
:C2  a  owl:Class;
     :prop  :C2 .

However, you cannot use owl:Class as the domain or range of an object property. The last possibility is to not care and use OWL (1/2) Full:

# works in OWL 1 Full, OWL 2 Full
:prop  rdfs:domain  owl:Class;
       rdfs:range  owl:Class .
:C1  a  owl:Class;
     :prop  :C2 .

Note that most OWL DL reasoners will not crash on that input (more precisely, all reasoners that I’ve ever tested would not crash), so it’s pretty safe in fact.