W3C home > Mailing lists > Public > public-rdf-wg@w3.org > April 2012

Re: Attempt to provide semantics to Sandro's named graph design

From: Andy Seaborne <andy.seaborne@epimorphics.com>
Date: Tue, 10 Apr 2012 15:06:19 +0100
Message-ID: <4F843E5B.7020507@epimorphics.com>
To: rdf-wg <public-rdf-wg@w3.org>
Ivan,

Most of it makes sense to me.

Could you explain the need for conditions 3, please?  I see the need for 
a local functional mapping from <ui> to Gi, but why the reverse condition?

It seems at odds with web style of multiple names for things and also of 
merging data at the RDF level without inconsistencies arising.

If a process reads location "URL" at two different times T1 and T2, gets 
the same triples GV, which it labels events E1 and E2,

then the app can't write

E1 { GV }
E2 { GV }

i.e. the use case for an archiving web crawler can't be addressed directly.

The cost of enforcing the condition when adding a new graph to an 
existing dataset is going to be not inconsiderable.


"Subgraphs or Graphs"

I don't think this is a local syntax issue. The parts of the labelling 
may be in different datasets, which are then brought together (actually, 
not possible by condition 3)

Within one TriG file, several <u> {} blocks may make one graph labelled 
<u> overall -- that is a syntax issue.

((I don't see why the merge of datasets isn't the merge of their graphs 
with the same URI + the (IRI, graph) pairs for non-overlapping IRIs.))


	Andy




On 10/04/12 14:42, Ivan Herman wrote:
> Guys,
>
> As a submission to tomorrow's discussion: I have tried to put some semantics 'meat' on the Sandro's skeleton design[1]. I have put it onto the wiki:
>
> http://www.w3.org/2011/rdf-wg/wiki/Graphs_Design_6.1/Sem
>
> it may provide a way to fold all this into the RDF Semantics with, I believe, a minimal amount of change to the current RDF Semantics (which is a plus for me!), pretty much as a separate section instead of rewriting the whole thing. It may also help in formulating some of the open issues.
>
> I believe it reflects what Sandro thinks although I may of course be wrong...
>
> Cheers
>
> Ivan
>
> [1] http://www.w3.org/2011/rdf-wg/wiki/Graphs_Design_6.1
>
>
> ----
> 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 Tuesday, 10 April 2012 14:06:55 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 22:02:04 UTC