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

some GRAPHS strawpolls for today (agenda?)

From: Sandro Hawke <sandro@w3.org>
Date: Wed, 25 Apr 2012 10:08:55 -0400
To: public-rdf-wg <public-rdf-wg@w3.org>
Message-ID: <1335362935.9663.321.camel@waldron>
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 14:09:08 GMT

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