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Re: Problem with property path test case pp15

From: Andy Seaborne <andy.seaborne@epimorphics.com>
Date: Mon, 18 Apr 2011 15:02:50 +0100
Message-ID: <4DAC448A.5020201@epimorphics.com>
To: Olivier Corby <Olivier.Corby@sophia.inria.fr>
CC: SPARQL Working Group <public-rdf-dawg@w3.org>
This needs fixing - literals should be included.

	Andy

On 08/04/11 08:23, Olivier Corby wrote:
> I think there is a problem with pp15
>
> SELECT *
> WHERE { ?X :p{0} "o" .
> ?Y :p{0} :o .
> :s :p{0} ?Z . }
>
> The query is applied to an empty graph and it returns:
>
> "o"
> :o
> :s
>
>
> However, the current SPARQL 1.1 Query document specifies:
>
> Definition: ZeroLengthPath
> A zero length path matches all subjects and objects in the graph, and
> also any IRIs explictly given as endpoints of the path pattern.
>
>
> But literal "o" is not an IRI and it is not in the graph, so the query
> should fail.
>
>
> In addition, what is the rationale for matching "IRIs explicitly given
> as endpoints of the path pattern" ?

Originally from:

?x rdf:type/rdfs:subClassOf* <T> .
---------
project ?x
   ?x rdf:type ?v . ?v rdfs:subClassOf* <T> .

so if there is no

<a> rdfs:subClassOf* <T> .

this works when done in either order:

   ?x rdf:type ?v . ?v rdfs:subClassOf* <T> .
or
    ?v rdfs:subClassOf* <T> . ?x rdf:type ?v .
>
>
> Olivier
>
Received on Monday, 18 April 2011 14:03:37 GMT

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