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Re: pfps-05 RDFS closure rules [not complete yet]

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Thu, 31 Jul 2003 19:59:20 -0400 (EDT)
Message-Id: <20030731.195920.128883250.pfps@research.bell-labs.com>
To: phayes@ihmc.us
Cc: bwm@hplb.hpl.hp.com, www-rdf-comments@w3.org

From: pat hayes <phayes@ihmc.us>
Subject: Re: pfps-05 RDFS closure rules [not complete yet]
Date: Thu, 31 Jul 2003 18:40:46 -0500

> >I believe that the rules for rdfs entailments are still incomplete in the
> >current version of RDF Semantics (Editors [sic] Draft July 27).
> >
> >For example, consider the RDF graph
> >
> >	ex:foo ex:bar "<"^^rdf:XMLLiteral .
> >	ex:bar rdfs:range rdf:XMLLiteral .
> >
> >I believe that this graph has no rdfs-intepretations
> 
> Yes, you are right. I had overlooked this case; and the proof 
> implicitly assumes that XML literals are wellformed.
> 
> I will modify the statement of the RDFS entailment lemma so as to 
> exclude such cases, by requiring the antecedent to be consistent. 

I would view this as an unsatisfactory outcome unless there was some
proof-theoretic way of describing rdfs-consistent sets of graphs.

> I 
> will also add explanatory text to section 5, which has a paragraph
> which curently ends:
> "An ill-typed literal does not in itself constitute an inconsistency, 
> but a graph which entails that an ill-typed literal has rdf:type 
> rdfs:Literal would be inconsistent."
> 
> to be modified to:
> 
> "An ill-typed literal does not in itself constitute an inconsistency, 
> but a graph which entails that an ill-typed literal has rdf:type 
> rdfs:Literal, or that an ill-typed XML literal has rdf:type 
> rdf:XMLLiteral, would be inconsistent."
> 
> Thanks for catching this.
> 
> Pat
> 
> 
> >  and thus that it
> >rdfs-entails
> >
> >	rdf:type rdf:type rdf:type .
> >
> >which I believe cannot be deduced from the RDFS entailment rules.
> >
> >peter

I also note that the use of ``derives'' is rather sloppy in the document.
As well, there is no entry for ``derivation'' in the glossary.

peter
Received on Thursday, 31 July 2003 20:00:50 GMT

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