- From: Jim Hendler <hendler@cs.rpi.edu>
- Date: Thu, 24 Jan 2008 10:01:43 -0500
- To: Alan Wu <alan.wu@oracle.com>
- Cc: OWL Working Group WG <public-owl-wg@w3.org>
- Message-Id: <F84CB7AD-4CD4-4427-92CA-4A6618B8144D@cs.rpi.edu>
Alan - this seems like a good step forward -My hope, through, is we'd do something that makes the DLP (extended as you suggest) be the DL version, and that it would be clear that the same restricted vocabulary set is a named fragment of OWL Full (i.e whatever name we assign to this, we would have FragX DL and FragX Full?) - I believe we made a mistake in the OWL 1.0 group in not having a "OWL F-LITE," and I'd hate to see that mistake propagated again. -JH On Jan 24, 2008, at 9:50 AM, Alan Wu wrote: > Hi, > > I am going to start with the following core set of RDFS 3.0 (http:// > www.w3.org/2007/OWL/wiki/Fragments) vocabularies because they are > the most frequently asked RDFS/OWL vocabularies Oracle has seen on > the field. Transitive properties, same as and inverse functional > properties, among others, are indispensable. > > - rdfs:domain > - rdfs:range > - rdfs:subClassOf > - rdfs:subPropertyOf > - owl:equivalentClass > - owl:equivalentProperty > - owl:sameAs > - owl:inverseOf > - owl:TransitiveProperty > - owl:SymmetricProperty > - owl:FunctionalProperty > - owl:InverseFunctionalProperty > > One can think of the above set as a minimum requirement that meets > the needs of applications Oracle is dealing with. This set happens > to be a subset of pD* vocabulary. Regarding the relationships > between this set and other OWL fragments, it seems that the above > vocabulary set is not covered by DL-Lite (missing transitive > properties for example) or EL++ (missing functional/inverse > functional properties for example). Carsten has helped a lot in > clarification (many thanks!). Ian and Boris also have been really > helpful and they kindly pointed me to the DLP paper and later the > DLP section on W3C fragment wiki page which seems to be a better > fit in the sense that all the above constructs are covered. > > For the syntax specification of the above vocabulary set (please > view in HTML mode), I shamelessly took the following from the > (WWW03 Grosof/Horrocks/Volz/Decker's) DLP paper and modified a tiny > bit. The HTML-based math symbols are from http://barzilai.org/ > math_sym.htm and http://us.metamath.org/symbols/symbols.html > > - rdfs:domain T <mime-attachment.gif> > ∀P‾.C > - rdfs:range T <mime- > attachment.gif> ∀P.C > - rdfs:subClassOf C1 <mime-attachment.gif> C2 > - rdfs:subPropertyOf P1 <mime-attachment.gif> P2 > - owl:equivalentClass C1 ≡ C2 > - owl:equivalentProperty P1 ≡ P2 > - owl:sameAs {i1} ≡ {i2} > - owl:inverseOf P1 ≡ P2‾ > - owl:TransitiveProperty P+ <mime-attachment.gif> P > - owl:SymmetricProperty P ≡ P‾ > - owl:FunctionalProperty T <mime-attachment.gif> ≤1 P > - owl:InverseFunctionalProperty T <mime-attachment.gif> ≤1 P‾ > - i type C i : C > - i1 P i2 <i1, i2> : P > > > The relevant entailment rules from the pD* paper can be used for > inference for an ontology based on the above vocabulary set. > Obviously, the above vocabulary set is very simple. It is > nonetheless very useful in practice. And I want to add that it is > non-trivial to support it efficiently in a large scale. > > At this moment, either pD* or DLP can be the semantic underpinning > of the above vocabulary set. Oracle is willing to adopt DLP so long > as there is a fixed set of rules similar to those described in pD* > paper. Having a complete, fixed set of entailment rules is critical > for the success of a database-based inference engine. There are > some differences in implementation, as pointed out by Ian and > Boris. Rather than quoting them here, I will leave it for Ian and > Boris to elaborate. > > Comments and corrections welcomed. > > Thanks, > > Zhe "If we knew what we were doing, it wouldn't be called research, would it?." - Albert Einstein Prof James Hendler http://www.cs.rpi.edu/~hendler Tetherless World Constellation Chair Computer Science Dept Rensselaer Polytechnic Institute, Troy NY 12180
Received on Thursday, 24 January 2008 15:02:25 UTC