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Re: some GRAPHS strawpolls for today (agenda?)

From: Peter F. Patel-Schneider <pfpschneider@gmail.com>
Date: Wed, 25 Apr 2012 10:17:30 -0400
Message-ID: <4F98077A.2060003@gmail.com>
To: Sandro Hawke <sandro@w3.org>
CC: public-rdf-wg <public-rdf-wg@w3.org>
Remember that there are some (myself included) who think that named graphs are 
the wrong type for entailment relationships.  I'll use a different message for 
my responses.

peter


On 04/25/2012 10:08 AM, Sandro Hawke wrote:
> If we're going to talk about graphs today, maybe we can do it in a
> series of decisions.   There's not enough notice to make these binding,
> of course, but maybe we can get a sense of how close we are to
> consensus.
>
> If we can't even get consensus on a few of these, these I think we
> should stop working on graph semantics in this WG.  I hope we're very
> close to consensus on all of these, except maybe the last, which I could
> see continuing as an open issue well into CR.
>
> I've erred on the side of brevity here.
>
>       -- Sandro
>
> ====================================
>
>
> 1. The default graph is asserted
>
>    "{<a>  <b>  <c>}" entails turtle("<a>  <b>  <c>")
>
> 2. Named graphs are not asserted
>
>    "<u>  {<a>  <b>  <c>}" does not entail turtle("<a>  <b>  <c>")
>
> 3. Named graphs are opaque
>
>    "<u>  {<a>  <b>  <c>}"  does not entail "<u>  {<a>  <b>  _:x}"
>
> 4. Graph labels denote just like in RDF
>
>    "{<u1>  owl:sameAs<u2>}<u1>  {<a>  <b>  <c>}"
>    owl-entails
>    "<u2>  {<a>  <b>  <c>}"
>
> 5. Blank nodes labels have file scope
>
>     See SPARQL queries in
>     http://www.w3.org/2011/rdf-wg/wiki/Graphs_Design_6.1#Blank_Nodes
>     or Skolemization example in
>     http://lists.w3.org/Archives/Public/public-rdf-wg/2012Apr/0132.html
>
> 6. In trig, @union can be used in place of the default graph
>
>     "@union<u>  {<a>  <b>  <c>}" entails turtle "<a>  <b>  <c>"
>
> 7. Datasets only say which triples are known to be in a named graph,
>     not which triples are *not* in that named graph.
>
>     The merge of "<u>  {<a>  <b>  <c>}" and "<u>  {<a>  <b>  <d>}" is
>     "<u>  {<a>  <b>  <c>,<d>}".
>
>     Also "<u>  {<a>  <b>  <c>,<d>}" entails "<u>  {<a>  <b>  <c>}".
>
>
>
Received on Wednesday, 25 April 2012 14:18:06 UTC

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