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Fwd: A question regarding the latest SPARQL 1.1 Proposed Recommendation

From: Andy Seaborne <andy.seaborne@epimorphics.com>
Date: Fri, 14 Dec 2012 08:58:54 +0000
Message-ID: <50CAEA4E.1090108@epimorphics.com>
To: SPARQL Working Group <public-rdf-dawg@w3.org>
I've fixed this in the editors working draft, hoping that's the right 
thing to do.

Does this need to go on some errata list somewhere as well?


-------- Original Message --------
Subject: A question regarding the latest SPARQL 1.1 Proposed Recommendation
Resent-Date: Thu, 13 Dec 2012 10:47:17 +0000
Resent-From: public-sparql-dev@w3.org
Date: Wed, 12 Dec 2012 08:55:12 +0100
From: Christopher Schramm <schramm@informatik.uni-luebeck.de>
To: public-sparql-dev@w3.org

Dear W3C,

i've encountered a problem while reading the SPARQL 1.1 Proposed
Recommendation of November 8.

The question i have is in regards to an example in section 9.2. The
example deals with Inverse Path Sequences and has the following example:

     ?x foaf:knows/^foaf:knows ?y .
     FILTER(?x != ?y)

is equivalent to

     ?x foaf:knows ?gen1 .
     ?gen1 foaf:knows ?y .
     FILTER(?x != ?y)

However, in my opinion it should be equivalent to

     ?x foaf:knows ?gen1 .
     ?y foaf:knows ?gen1 .
     FILTER(?x != ?y)

Otherwise i fail to see the difference between the orgininal query and
the same query without an inversion. I would like to hear your opinion
on the matter. Moreover i have a question regarding the following query:

     ?x ^(foaf:a/foaf:b) ?y .

I would think, that the equivalent query would be the following:

     ?y foaf:b ?gen1 .
     ?gen1 foaf:a ?x .

Am i correct there?

Thank you for answers.


Christopher Schramm
Received on Friday, 14 December 2012 08:59:23 UTC

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