Fwd: LC comments 18, 19, 59

Uli asked me to forward these draft replies.

Before sending them, she needs to update the relevant specs with the  
fixes, but will do so after or on the trip back from her vacation  
(which ends this week).

If the WG is good with these, then she can do the changes and ship.

Cheers,
Bijan.

> -------
>
> Dear Maurizio,
>
> Thank you for your message
> http://lists.w3.org/Archives/Public/public-owl-comments/2009Jan/ 
> 0014.html
> on the OWL 2 Web Ontology Language last call drafts.
>
> Your comment is closely related to the one by Misha (see  http:// 
> lists.w3.org/Archives/Public/public-owl-comments/2009Jan/0019.html)  
> and Ivan (see http://www.w3.org/mid/49881F19.7040209@w3.org).
>
> The working group has decided to implement the editorial changes  
> and will correct the typos, thanks for pointing the out. We have  
> also decided to add, to OWL 2 QL, reflexive, irreflexive, &  
> asymmetric property axioms. Moreover, we will fix the inaccuracies  
> in the complexity table, following suggestions by Misha and  
> discussions with you: for data complexity, we will add that OWL 2  
> QL is in AC_0, i.e., queries are first order rewritable and that  
> the taxonomic complexity is NLogSpace-complete. Finally, we have  
> decided *not* to add sameAs to OWL 2 QL, but to add a small  
> paragraph that explains that, if one wants to handle ontologies  
> that are OWL 2 QL plus sameAs, then a preprocessing step that  
> materialises the sameAs relation or an extension of the rewriting  
> technique that rewrites into recursive queries can be used, see  
> http://www.w3.org/2007/OWL/meeting/2009-02-24#OWL_QL .
>
>  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,
> Peter F. Patel-Schneider
> on behalf of the W3C OWL Working Group
>
> -------
>
> Dear Misha and Roman,
>
> Thank you for your message
> http://lists.w3.org/Archives/Public/public-owl-comments/2009Jan/ 
> 0019.html
> on the OWL 2 Web Ontology Language last call drafts.
>
> Your comment is closely related to the one by Maurizio (see  http:// 
> lists.w3.org/Archives/Public/public-owl-comments/2009Jan/0014.html)  
> and Ivan (see http://www.w3.org/mid/49881F19.7040209@w3.org).
>
> The working group has decided to implement the editorial changes  
> and will correct the typos, thanks for pointing the out. We have  
> also decided to add, to OWL 2 QL, reflexive, irreflexive, &  
> asymmetric property axioms. Moreover, we will fix the inaccuracies  
> in the complexity table, following your suggestions and discussions  
> with Maurizio: for data complexity, we will add that OWL 2 QL is in  
> AC_0, i.e., queries are first order rewritable and that the  
> taxonomic complexity is NLogSpace-complete. Finally, we have  
> decided *not* to add sameAs to OWL 2 QL, but to add a small  
> paragraph that explains that, if one wants to handle ontologies  
> that are OWL 2 QL plus sameAs, then a preprocessing step that  
> materialises the sameAs relation or an extension of the rewriting  
> technique that rewrites into recursive queries can be used, see  
> http://www.w3.org/2007/OWL/meeting/2009-02-24#OWL_QL .
>
>  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,
> Peter F. Patel-Schneider
> on behalf of the W3C OWL Working Group
>
> -------
>
> Dear Ivan,
>
> Thank you for your message
> http://www.w3.org/mid/49881F19.7040209@w3.org
> on the OWL 2 Web Ontology Language last call drafts.
>
> Your comment is closely related to the one by Maurizio (see  http:// 
> lists.w3.org/Archives/Public/public-owl-comments/2009Jan/0014.html)  
> and Misha (see http://lists.w3.org/Archives/Public/public-owl- 
> comments/2009Jan/0019.html).
>
> The working group has decided to implement the editorial changes  
> and will correct the typos, thanks for pointing the out. We have  
> also decided to add, to OWL 2 QL, reflexive, irreflexive, &  
> asymmetric property axioms.
>
> Finally, we have decided *not* to add sameAs or functional  
> properties to OWL 2 QL:
>
> - [sameAs] OWL 2 QL was designed so that any query Q against an  
> ontology whose data (i.e., information about individuals, the  
> classes they are instances of and how they are related via  
> properties) is stored in a relational database DB, can be answered  
> by rewriting the query Q into an SQL query Q1 and then answering Q1  
> against DB using a standard RDBMs. This property is known to be  
> lost in the presence of sameAs. For the LOD community, we will add  
> a small paragraph explaining that, in order to handle OWL 2 QL plus  
> sameAs, a preprocessing step that materialises the sameAs relation  
> or an extension of the rewriting technique that rewrites into  
> recursive queries can be used, see http://www.w3.org/2007/OWL/ 
> meeting/2009-02-24#OWL_QL .
>
> - functional properties can only be added under the so-called  
> unique name assumption, i.e., different names denote different  
> indiviudals. This assumption, together with functional properties,  
> will lead to inconsistencies if an individual has 2 successors  
> w.r.t. a functional property -- a semantics that is suitable for  
> some applications and unsuitable for others. Hence we have chosen  
> to not include functional properties to OWL 2QL.
>
>  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,
> Peter F. Patel-Schneider
> on behalf of the W3C OWL Working Group
>
>
>

Cheers,
Bijan.

Received on Tuesday, 17 March 2009 19:15:27 UTC