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Re: Labelled graphs

From: Andy Seaborne <andy.seaborne@epimorphics.com>
Date: Mon, 16 Apr 2012 13:07:33 +0100
Message-ID: <4F8C0B85.9080205@epimorphics.com>
To: public-rdf-wg@w3.org


On 15/04/12 15:57, Sandro Hawke wrote:
> On Sat, 2012-04-14 at 20:35 +0100, Andy Seaborne wrote:
>> On 13/04/12 11:33, Steve Harris wrote:
>>>> Read that as rdf:aaa to avoid natural language meaning.
>>> I don't get that, but…
>>
>> Natural language can be confusing.
>>
>> <u>  rdf:label G .
>>
>> so is<u>  labelled by G ?
>>      "<u>  has a label of G"
>>      "G is a label for<u>"
>>
>> or is<u>  labelling G ?
>>      "<u>  is a label for G"
>>      "G has a label of<u>"
>>
>> (sometimes it does not matter -- e.g. sameValue).
>>
>> "labelled graphs" is more of the style"<u>  is a label of G".
>>
>> All that is needed as the most basic building block is a neutral
>> association of (<u>, G) and that within a dataset (<ui>, Gi) is
>> functional from<ui>  to Gi : given a label, find the associated graph.
>
> With these looser semantics, I don't think it needs to be functional.
> Rather, I think we can define it as labeling the associated graph and
> each of its subgraphs.
>
> There would be some kind of deep equivalence between these two datasets:
>
> D1:
>     <u>  {<a>  <b>  1 }
>     <u>  {<a>  <b>  2 }
> and
> D2:
>     <u>  {<a>  <b>  1,2 }
>
> The SPARQL semantics might written in terms of a normal form, where a
> term is only used as a label once, but the other forms would be valid in
> trig and in the RDF Semantics.

In earlier threads, the proposal was that a TriG document had one graph 
per label but (syntax) it may be split into separate sections for 
practical reasons.

	Andy
Received on Monday, 16 April 2012 12:08:10 UTC

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