W3C home > Mailing lists > Public > www-archive@w3.org > December 2007

Re: POWDER: my rabbit

From: Jeremy Carroll <jjc@hpl.hp.com>
Date: Mon, 17 Dec 2007 16:22:28 +0000
Message-ID: <4766A244.5020104@hpl.hp.com>
To: Phil Archer <parcher@icra.org>
CC: www-archive@w3.org, "Carroll, Jeremy John" <jeremy.carroll@hp.com>, Dan Brickley <danbri@danbri.org>, "Williams, Stuart (HP Labs, Bristol)" <skw@hp.com>, Ivan Herman <ivan@w3.org>, Bijan Parsia <bparsia@cs.man.ac.uk>

Jeremy Carroll wrote:

> f)
> The GRDDL transform transforms


I thought I should say a bit more about what I had in mind here.

At
http://www.w3.org/TR/2007/WD-powder-dr-20070925/#structure


we find
11   <wdr:hasDescriptors>
12     <wdr:Descriptors>
13       <ex:property1>value 1</ex:property1>
14       <ex:property2>value 2</ex:property2>
15     </wdr:Descriptors>
16   </wdr:hasDescriptors>

Operationally, every resource in the resource set is required to match 
this template, i.e. if xxx is the URI of a resource in the resource set.

12     <rdf:Description rdf:about="xxx">
13       <ex:property1>value 1</ex:property1>
14       <ex:property2>value 2</ex:property2>
15     </rdf:Description>

is true.

Formally, without the GRDDL transform, we essentially can just pick one 
of the resources in the resource set (which I think should never be 
empty), and this then gives a fairly weak formal semantics where 
hasDescriptors basically picks out an example from the resource set.

With the GRDDL reading, we turn from an example to a stronger subClassOf 
reading, with each of the properties (ex:property1, ex:property2 etc) 
being transformed into a hasValue restriction, so that formally, we have 
the stronger reading, that every member of the non-empty resource set is 
described by the block 12-15 above.

Jeremy
Received on Monday, 17 December 2007 16:23:12 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Wednesday, 7 November 2012 14:18:12 GMT