W3C home > Mailing lists > Public > www-rdf-comments@w3.org > October to December 2002

comments on current (6 Nov) draft of RDF MT document

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Wed, 06 Nov 2002 23:33:35 -0500 (EST)
Message-Id: <20021106.233335.58013180.pfps@research.bell-labs.com>
To: www-rdf-comments@w3.org
Cc: www-webont-wg@w3.org

I took at look at the RDF MT document to see what changes needed to be done
to the OWL MT and found a few problems.

1/ The change to make LV a subset of IR has not found its way into several
places in the document.  In particular, there definition of a simple
interpretation mentions IR union LV.

2/ IP is not introduced in Section 3.1.  Is IP a component of an RDF
interpretation? 

3/ The condition on IEXT in Section 3.1 does not follow from RDF M&S.  It
only follows from RDFSS.  In fact, rdf:Resource does not appear at all in
RDF M&S.

4/ The IEXT condition on rdf:Property in an rdf-interpretation is only
implied by the ICEXT condition on rdf:Property in rdfs-interpretations.

5/ The closure condition rdf1 is not valid in rdf-interpretations.
Therefore, the RDF entailment lemma is false.

6/ The RDFS closure rules are missing several classes, ranges, and
subclasses.

7/ The RDFS closure rules are incomplete, even if the above problems are
   fixed.  Therefore, the RDFS entailment lemma is false.

   For example, rdf:type rdfs:domain foo . 
                a b c .
		RDFS-entails
		a rdf:type foo .
   because every resource has rdfs:Resource as a type, as I have pointed
   out before. 
   Also, a b c .
         RDFS-entails
	 a rdf:type rdfs:Class .
   because every resource is a subClassOf rdfs:Resource
   and, rdfs:subClassOf rdfs:domain foo .
	a b c . 
	RDFS-entails
	a rdf:type foo .
   because 

Peter F. Patel-Schneider
Bell Labs Research

	
Received on Wednesday, 6 November 2002 23:33:43 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Friday, 21 September 2012 14:16:31 GMT