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Re: pfps-04 [RDF entailment rules not yet complete]

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Thu, 31 Jul 2003 10:11:28 -0400 (EDT)
Message-Id: <20030731.101128.45266591.pfps@research.bell-labs.com>
To: bwm@hplb.hpl.hp.com
Cc: www-rdf-comments@w3.org, phayes@ai.uwf.edu

From: Brian McBride <bwm@hplb.hpl.hp.com>
Subject: Re: pfps-04 [RDF entailment rules not yet complete]
Date: 31 Jul 2003 14:23:01 +0100

> Peter wrote:
> 
> [[
> I believe that the rules for rdf entailments are still incomplete in 
> RDF Semantics (Editors [sic] Draft of July 27).
> 
> For example, consider the RDF graph
> 
> 	ex:foo ex:bar "<ex/>"^^rdf:XMLLiteral .
> 
> I believe that this graph rdf-entails
> 
> 	ex:foo ex:bar "<ex></ex>"^^rdf:XMLLiteral .
> ]]
> 
> Is "<ex/>" a member of the lexical space of rdf:XMLLiteral?  I don't
> think so: 
> 
> http://www.w3.org/2001/sw/RDFCore/TR/WD-rdf-concepts-20030117/#section-XMLLiteral
> 
> [[
> The lexical space
>         is the set of all strings which: 
>               * are well-balanced, self-contained XML data [XML];
>               * correspond to exclusive Canonical XML  (with comments,
>                 with empty InclusiveNamespaces PrefixList) [XML-XC14]
> ]]
> 
> "<ex/>" does not correspond to exclusive canonical XML; it would have to
> be "<ex></ex>".
> 
> Brian

I am unconvinced.  Just what does ``correspond'' mean here - does it mean
``are'' or does it mean ``resulting in ... when canonicalized''?  I give it
the second meaning, so that "<em></em>" is in the lexical space, but "<" is
not.

I note that the relevant pointers in RDF Semantics are still broken.  

I also note that if the first meaning is indeed correct, then much of the
treatment of XML literals in RDF Semantics needs to be changed.

Peter F. Patel-Schneider
Bell Labs Research
Lucent Technologies
Received on Thursday, 31 July 2003 10:11:42 GMT

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