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Re: rdfs:Graph ? comment on http://www.w3.org/TR/rdf11-concepts/#section-dataset and issue 35

From: Jeremy J Carroll <jjc@syapse.com>
Date: Tue, 17 Sep 2013 18:02:59 -0700
Cc: www-archive@w3.org, Pat Hayes <phayes@ihmc.us>
Message-Id: <F91BD44B-7454-4CB5-8BC9-2765892C0EE9@syapse.com>
To: Sandro Hawke <sandro@w3.org>
I haven't yet read your epiphany message, so maybe my comments here will already be out of date 



On Sep 17, 2013, at 11:45 AM, Sandro Hawke <sandro@w3.org> wrote:

> On 09/17/2013 12:35 PM, Jeremy J Carroll wrote:
>> 
> 
> Oh, okay.  So, test case:
> 
>   :gn1 rdf:namesGraph :g1;
>           owl:sameAs :gn2.
>   GRAPH :gn1 { :a :b :c }.
> entails
>   :gn2 rdf:namesGraph :g1;
> 
> Yes?

In OWL this entailment follows from the default graph - correct.

> 
> Are there any cardinality constraints?    I think you're saying it's a functional property, so 
> 
>  :gn1 rdf:namesGraph :g1a, :g1b.
>  :g1a :p :o.
> entails
>  :g1b :p :o.
>   

I don't think I did say that (although I have to return to my text to check that I didn't say it by accident!)

For an interpretation of a graph in which :gn1 is not the name of a graph in some relevant dataset I was studiously silent.

>>> 
>> 
>> I am only using rdf:namesGraph to convey the semantic intent that the subject really is a graph name, since the working group resists making that a general rule
> 
> It resists making it a general rule, because there's no consensus, when you get into the details, what it means.   Everyone is fine with the general idea, sure, of course, that's the graph name and that's the graph, and (waving hands) in some sense that graph name is naming that graph.   But when you try to figure out details like entailments, disagreement start to arise that would break interoperability.    We don't want to hand out directions to where the party is unless we can actually write directions that will get everyone to the same spot.    So far, no one's been able to write directions that get even the folks in the WG to the same spot.

The general principle of RDF semantics standardization seems to me to be, if you cannot get consensus on an entailment, then it is a non-entailment.
I think I said there was no additional entailments: I offered no changes to the RDF Semantics.

Sorry out of time for today, more later

Jeremy
Received on Wednesday, 18 September 2013 01:03:31 UTC

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