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Re: ACTION-54 definition of OWLPrime (RDFS 3.0)

From: Jim Hendler <hendler@cs.rpi.edu>
Date: Thu, 24 Jan 2008 10:01:43 -0500
Message-Id: <F84CB7AD-4CD4-4427-92CA-4A6618B8144D@cs.rpi.edu>
Cc: OWL Working Group WG <public-owl-wg@w3.org>
To: Alan Wu <alan.wu@oracle.com>
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 GMT

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