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Re: RDF/XML shorthand for RDF reification

From: Ian Horrocks <ian.horrocks@comlab.ox.ac.uk>
Date: Thu, 26 Jun 2008 14:30:58 +0100
Message-Id: <E0AD93D3-306F-4767-B094-E6C4EA10D95A@comlab.ox.ac.uk>
Cc: Alan Ruttenberg <alanruttenberg@gmail.com>, Peter Patel-Schneider <pfps@research.bell-labs.com>, OWL Working Group WG <public-owl-wg@w3.org>
To: Ivan Herman <ivan@w3.org>

I find the combination of Ivan's argument (we should not rely on the  
particularities, oddities, etc, of one particular RDF serialization)  
and Peter's argument (we would need to be sure that nothing in the  
mapping or semantics is adversely affected) to be very compelling.

Ian


On 26 Jun 2008, at 10:32, Ivan Herman wrote:

> I was actually surprised to see that Peter was right:-) I must  
> admit that I thought myself that the rdf:nodeId could also be used  
> in that position (generating a blank node for the reified  
> statement) but, indeed,
>
> http://www.w3.org/TR/rdf-syntax-grammar/#section-Syntax-reifying
>
> refers to rdf:ID only. Having said that (and that may be the  
> reason) I do not think I have ever seen this rdf:ID+reification  
> trick ever used in practice...
>
> As both Alan and Peter said: this is independent on whether the  
> reified triple should appear in the RDF graph explicitly or not.  
> Actually (I am sorry Alan...) I do not think any RDF/XML syntax  
> trick (whether there is a remedy or not) has any relevance here.  
> Indeed, we should not rely on the particularities, oddities, etc,  
> of one particular RDF serialization and we should keep to the RDF  
> model. For the record, I believe Alan is right and we should have  
> that extra triple in the graph; I saw no reason why we wanted to  
> differentiate ourselves from RDFS/OWL Full semantics at that point...
>
> Ivan
>
> Alan Ruttenberg wrote:
>> On Jun 25, 2008, at 3:50 PM, Peter F. Patel-Schneider wrote:
>>> The point I was making was that using the shorthand results in the
>>> reification node having a real name, i.e., not being a blank  
>>> node, which
>>> messes up lots of things, including parsing and semantics.   
>>> Therefore,
>>> arguments that rely on using the shorthand are not applicable, at  
>>> least
>>> without doing some investigation to see whether there is a remedy.
>> OK. I see this now. Good point. I'll poke around to see if there  
>> is a remedy.
>> -Alan
>>>
>>> This has nothing to do whether one would like to have the base  
>>> triple or
>>> not.
>>>
>>> peter
>>>
>>> From: Alan Ruttenberg <alanruttenberg@gmail.com>
>>> Subject: Re: RDF/XML shorthand for RDF reification
>>> Date: Wed, 25 Jun 2008 14:40:03 -0400
>>>
>>>> The point I was making is that it that I though that it was  
>>>> unreasonable
>>>> for owl not to have the reified triple, and therefore this is well
>>>> suited ;-)
>>>>
>>>> I also pointed out that it nullified the argument that there was an
>>>> additional parsing burden to parse the "extra" actual reified  
>>>> triple. In
>>>> effect the RDF/XML shorthand makes the parsing burden for a fully
>>>> reified triple only slightly more than for the triple itself.
>>>>
>>>> -Alan
>>>>
>>>> On Jun 25, 2008, at 2:15 PM, Peter F. Patel-Schneider wrote:
>>>>
>>>>>
>>>>> It appears to me that the RDF/XML shorthand for RDF reification  
>>>>> creates
>>>>> named reification, i.e., it names the reified triple.  I  
>>>>> believe that
>>>>> this means that its use is not reasonable for OWL.
>>>>>
>>>>> peter
>
> -- 
>
> Ivan Herman, W3C Semantic Web Activity Lead
> Home: http://www.w3.org/People/Ivan/
> PGP Key: http://www.ivan-herman.net/pgpkey.html
> FOAF: http://www.ivan-herman.net/foaf.rdf
Received on Thursday, 26 June 2008 13:31:41 GMT

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