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Re: [Fwd: Comments on SPARQL] (entailment, soundness, completeness)

From: Dan Connolly <connolly@w3.org>
Date: Fri, 09 Sep 2005 18:20:33 -0500
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
Cc: public-rdf-dawg-comments@w3.org
Message-Id: <1126308033.4430.382.camel@dirk>

On Fri, 2005-09-09 at 19:19 -0400, Peter F. Patel-Schneider wrote:
> 
> >The WG as a whole hasn't expressed a preference directly, but in
> >drafting the definitions and considering simple test cases, the
> >details of subgraph seemed to work out and the details of entailment
> >seemed not to. For example, here's part of one message from 09 Jun 2005
> >
> >
> >[[[
> >The difference is observable from an approved*** test
> >  http://www.w3.org/2001/sw/DataAccess/tests/#dawg-triple-pattern-001
> >
> >input:
> > :x :p :v1 .
> > :x :p :v2 .
> >
> >query:
> >  SELECT *
> >WHERE { :x ?p ?q . }
> >
> >By the simple-entailment definition, there are solutions that bind
> >?p to _:foo, but there are no such results in the test results.
> >I suppose it's possible that the spec could prune the results
> >down to the ones in the test suite some other way, but I can't
> >think of any other straightforward way just now.
> >]]]
> > -- Re: Restructure definition of Basic Graph Pattern and pattern match (sec 2.4)
> >http://lists.w3.org/Archives/Public/public-rdf-dawg/2005AprJun/0359
> >
> >  
> >
> 
> Hmm.  I don't think so.  Binding ?p to _:foo doesn't result in an RDF 
> graph, as far as I know, and thus can't participate in an entailment 
> relationship.

Oops... try binding ?q to _:foo.

> Peter F. Patel-Schneider
> Bell Labs Research
> 
-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
D3C2 887B 0F92 6005 C541  0875 0F91 96DE 6E52 C29E
Received on Friday, 9 September 2005 23:20:37 GMT

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