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Re: A proposal for the fragments document

From: Jim Hendler <hendler@cs.rpi.edu>
Date: Wed, 12 Mar 2008 20:55:14 -0400
Cc: "'Michael Schneider'" <schneid@fzi.de>, <public-owl-wg@w3.org>
Message-Id: <223A1689-30D1-4C31-8815-862D9AE138EA@cs.rpi.edu>
To: Boris Motik <boris.motik@comlab.ox.ac.uk>

I actually have some questions about the choices of features in the  
fragment, and some things left out (most of the non-semantic features  
- like imports and annotations, which I think are important to the  
community).  I want to make clear that the proposal that I've been  
backing from the beginning is not to create the maximal set of OWL  
that can be expressed in rules, but rather a set designed with many  
different factors in mind (including ease of implementability with the  
syntax, so I'd prefer not to include restrictions).  The original RDFS  
submissions, and the rule set we submitted are what we've proposed.
  At this point I'm not trying to have this disucssion, but to ask how/ 
where we should have it.  We decided not to have the TF, but then I  
discovered there'd been some extensions to the first version I'd seen  
(my fault, not yours) and thus I do want to have some design  
discussion - may not need the whole WG .
  -JH



On Mar 11, 2008, at 12:45 PM, Boris Motik wrote:

>
> Hello Michael,
>
> Thanks for these corrections! I've corrected most of them, apart  
> from the ones I mention below; for some I have additional
> questions.
>
>> -----Original Message-----
>> From: Michael Schneider [mailto:schneid@fzi.de]
>> Sent: 11 March 2008 13:04
>> To: Boris Motik
>> Cc: public-owl-wg@w3.org; bcg@cs.man.ac.uk
>> Subject: RE: A proposal for the fragments document
>>
>
> [snip]
>
>> * Table 2 and 3: For the rules with a list as an argument  
>> ("intersectionOf", unionOf): The list head
>> should be the RHS, but currently is the LHS. e.g.: Currently: "T(? 
>> x1 intersectionOf ?c)" but should
>> be "T(?c intersectionOf ?x1)" ("x1" denotes the list head).
>>
>
> I'm not sure I understand this comment. If C is an intersection of  
> C1 and C2, then this is serialized as
>
> classID owl:intersectionOf T(SEQ description1 ... descriptionn) .
>
> In the rules, ?x1 is matched to the list, and ?c is matched to the  
> class, so we need in the rule the triple "T(?c,
> owl:intersectionOf, ?x1)", and this is what we indeed have.
>
>> * Table 2 and 3: It is "rdf:subPropertyOf" ("rdf:*"!) but should be  
>> "rdfs:subPropertyOf". Ditto (but
>> with "owl:") for "intersectionOf" and "unionOf".
>>
>
> I'm not sure I understand this comment.
>
>> * Perhaps not really editorial: There is no rule for  
>> "owl11:ReflexiveProperty", but the other new
>> property characteristics of OWL-1.1 have rules. Was this ommission  
>> intended?
>>
>
> OWL-R cannot safely support reflexive properties: such properties  
> depend on the entire domain, so this means that we potentially
> cannot consider just the explicitly mentioned objects.
>
>
> Thanks again for these comments; I really appreciate them!
>
> Regards,
>
> 	Boris
>
>

"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, 13 March 2008 00:55:55 GMT

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