- From: Peter F. Patel-Schneider <pfpschneider@gmail.com>
- Date: Wed, 25 Apr 2012 10:17:30 -0400
- 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