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TopQuadrant supports Feature:PropertyPaths

From: Holger Knublauch <holger@topquadrant.com>
Date: Thu, 5 Mar 2009 11:32:14 -0800
Message-Id: <D0F51A4A-547A-4AF9-AA3A-7AEAE1C4AB7A@topquadrant.com>
To: public-rdf-dawg-comments@w3.org
Dear SPARQL Working Group,

TopQuadrant (W3C member) supports the addition of Property Paths [1]  
to the upcoming version of SPARQL. Our main use case for this is "on- 
the-fly" inferencing so that hierarchies of sub-classes and properties  
can be traversed transitively. For example, the following query  
returns all instances of :Rectangle or the sub-classes of :Rectangle.  
This dramatically reduces the need to rely on any natively built-in  
inference capabilities of a triple store, and thus makes queries more  
platform independent.

SELECT ?instance
WHERE {
     ?type rdfs:subClassOf* :Rectangle .
     ?instance a ?type .
}

If generic path expressions (+ etc) are out of scope, we would at  
least appreciate the * operator as shown above, or another mechanism  
with similar expressivity.

Regards,
Holger

[1] http://www.w3.org/2009/sparql/wiki/Feature:PropertyPaths
Received on Thursday, 5 March 2009 19:32:58 GMT

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