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Re: New Proposal (6.1) for GRAPHS

From: Ivan Herman <ivan@w3.org>
Date: Thu, 29 Mar 2012 09:49:30 +0200
Cc: Sandro Hawke <sandro@w3.org>, public-rdf-wg <public-rdf-wg@w3.org>
Message-Id: <B5F088EE-B418-45DD-B7EA-16DAEDA1BFAA@w3.org>
To: Steve Harris <steve.harris@garlik.com>

On Mar 28, 2012, at 21:07 , Steve Harris wrote:

>> 
>>>> My alternative would be to describe 'hasGraph' as NOT an RDF property. However, we can define a class, much as your rdf:Graph class (say, rdf:GraphLabel) and say that:
>>>> 
>>>> <u> { a b c. }
>>>> 
>>>> entails 
>>>> 
>>>> <u> rdf:type rdf:GraphLabel
>>> 
>>> I don't see the value in making such a class.  Since any rdf:Resource
>>> can be used as a graph label (semantically, if not syntactically), I
>>> don't see this providing any functionality.
>> 
>> See SteveH mail. I may want to know whether a specific URI is used as a graph label or not. By automatically assigning it a type, it becomes a trivial thing to do in, say, SPARQL…
> 
> Just to be clear, I would not be in favour of inferring it from its presence in the 4th/0th column. 

Understood.

Ivan


> 
> My example was meant to discuss the case where it's explicitly asserted.
> 
> - Steve
> 
> 
>>>> And we would also have something like
>>>> 
>>>> rdf:Graph rdfs:subClassOf rdf:GraphLabel
>>>> 
>>>> 
>>>> 2. related to the Extension part:
>>>> 
>>>> http://www.w3.org/2011/rdf-wg/wiki/Graphs_Design_6.1#Extensions
>>>> 
>>>> Is there any reason why we could not rdf:GraphStateResouce in the current spec? By having it as a separate class it does not interfere with applications that require only the basic labeling, but, as you yourself argued for it many times, in some applications (eg, related to Linked Data) having that 'semantics' clearly defined would make sense.
>>> 
>>> Perhaps not.  I'm just a bit scared of the obvious time dependence.
>>> I'd rather we agree on everything else this proposal covers -- with the
>>> understanding that something like this can be defined -- and then, the
>>> following week perhaps, see if we can agree on something like this.
>> 
>> That is fine with me.
>> 
>> Ivan
>> 
>> 
>>> 
>>> -- Sandro
>>> 
>>>> Ivan
>>>> 
>>>> 
>>>> 
>>>> 
>>>> On Mar 28, 2012, at 04:23 , Sandro Hawke wrote:
>>>> 
>>>>> I've written up design 6 (originally suggested by Andy) in more
>>>>> detail.  I've called in 6.1 since I've change/added a few details that
>>>>> Andy might not agree with.  Eric has started writing up how the use
>>>>> cases are addressed by this proposal.
>>>>> 
>>>>> This proposal addresses all 15 of our old open issues concerning graphs.
>>>>> (I'm sure it will have its own issues, though.)
>>>>> 
>>>>> The basic idea is to use trig syntax, and to support the different
>>>>> desired relationships between labels and their graphs via class
>>>>> information on the labels.  In particular, according to this proposal,
>>>>> in this trig document:
>>>>> 
>>>>> <u1> { <a> <b> <c> }
>>>>> 
>>>>> ... we only know that <u1> is some kind of label for the RDF Graph <a>
>>>>> <b> <c>, like today.  However, in his trig document:
>>>>> 
>>>>> { <u2> a rdf:Graph }
>>>>> <u2> { <a> <b> <c> }
>>>>> 
>>>>> we know that <u2> is an rdf:Graph and, what's more, we know that <u2>
>>>>> actually is the RDF Graph { <a> <b> <c> }.  That is, in this case, we
>>>>> know that URL "u2" is a name we can use in RDF to refer to that g-snap.
>>>>> 
>>>>> Details are here: http://www.w3.org/2011/rdf-wg/wiki/Graphs_Design_6.1
>>>>> 
>>>>> That page includes answers to all the current GRAPHS issues, including
>>>>> ISSUE-5, ISSUE-14, etc.
>>>>> 
>>>>> Eric has started going through Why Graphs and adding the examples as
>>>>> addressed by Proposal 6.1:
>>>>> http://www.w3.org/2011/rdf-wg/wiki/Why_Graphs_6.1
>>>>> 
>>>>>  -- Sandro (with Eric nearby)
>>>>> 
>>>>> 
>>>> 
>>>> 
>>>> ----
>>>> Ivan Herman, W3C Semantic Web Activity Lead
>>>> Home: http://www.w3.org/People/Ivan/
>>>> mobile: +31-641044153
>>>> FOAF: http://www.ivan-herman.net/foaf.rdf
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>> 
>>> 
>>> 
>> 
>> 
>> ----
>> Ivan Herman, W3C Semantic Web Activity Lead
>> Home: http://www.w3.org/People/Ivan/
>> mobile: +31-641044153
>> FOAF: http://www.ivan-herman.net/foaf.rdf
>> 
>> 
>> 
>> 
>> 
> 
> -- 
> Steve Harris, CTO
> Garlik, a part of Experian 
> 1-3 Halford Road, Richmond, TW10 6AW, UK
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> 


----
Ivan Herman, W3C Semantic Web Activity Lead
Home: http://www.w3.org/People/Ivan/
mobile: +31-641044153
FOAF: http://www.ivan-herman.net/foaf.rdf







Received on Thursday, 29 March 2012 07:48:24 GMT

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