Rinke Hoekstra

The OWL WG of the W3C is currently discussing whether the OWL2 language should include a universal role, i.e. a top property that relates all individuals in the domain (see e.g. ISSUE-112 and email thread). Although it was already present in the SROIQ description logic that lies at the heart of the new OWL2 DL proposal, the implementation of an efficient reasoning algorithm for this property is not solved yet.

However, the property itself can be defined by adding the following axioms (from this email by Boris Motik):

(1)  SubClassOf( owl:Thing hasValue( U ni ) )
(2)  ReflexiveProperty( U )
(3)  SymmetricProperty( U )
(4)  TransitiveProperty( U )

Alternative representations using property chains do not require the restriction on owl:Thing. See for examples the papers by Markus Krötzsch, available on his homepage, which describe alternative representations, proofs, and interesting use cases.

You can import the above definitions for use in your own ontology from:

http://www.leibnizcenter.org/ontostore/universal-role.owl