LC Responses/BM1

To: Boris Motik <boris.motik@comlab.ox.ac.uk>
CC: public-owl-comments@w3.org
Subject: [LC response] To Boris Motik

Dear Boris,

Thank you for your comment
     <http://lists.w3.org/Archives/Public/public-owl-wg/2009Jan/0047.html>
on the OWL 2 Web Ontology Language last call drafts.

Thanks for pointing out this mistake! The theorem has been updated.

Please acknowledge receipt of this email to <mailto:public-owl-comments@w3.org> (replying to this email should suffice). In your acknowledgment please let us know whether or not you are satisfied with the working group's response to your comment.

Regards,
Boris Motik
on behalf of the W3C OWL Working Group

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the theorem to hold, the entailed ontology should not contain DifferentInfividuals. This minor oversight is demonstrated by the fact
that the ontology

A(a)
B(b)
DisjointClasses( A B )

entails

Differentindividuals( a b )

under the DirectSemantics; however, the OWL 2 RL/RDF rules do not entail the triple

<a, owl:differentIndividuals, b>.

The bug was in that DifferentIndividuals involves negation, but the OWL 2 RL/RDF rules preserve only the positive facts. We can fix
this by deleting DifferentIndividuals from the list of allowed assertions in the entailed ontology. This change obviously does not
impact the implementations; therefore, I believe we can just fix this bug in the Wiki without too much trouble. Please let me know
if you object to this.