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Re: Changes to make S&AS consistent with RDF Semantics document

From: Jeremy Carroll <jjc@hpl.hp.com>
Date: Mon, 15 Dec 2003 09:08:51 +0100
To: www-webont-wg@w3.org
Message-Id: <200312150908.51220.jjc@hpl.hp.com>


If at some point we were to change the design in the way that Herman apperas 
to want (or perhaps to change the understanding of the design reflected in 
the test document), then the tests misc-201 thru to 205 would need to be 
examined. We would then obsolete #205 whose manifest indicates that the test 
is not valid when XMLLiteral is a supported datatype.#204 is identical except 
giving the opposite result when XMLLiteral is supported  i.e. the test 
document makes it clear that this is a substantive issue.

 ==

I agree with Pat's comments about timeliness ...

While Herman is undoubtedly correct to indicate that this is a logical wart on 
the Semantic Web docs it is not a disaster. 

The indended meaning of the RDF docs is clear

The intended meaning of the OWL docs is clear

I note that the following implementation sketch describes an implementation 
that is both RDF conformant and OWL conformant, and exercises the parts of 
the specs that Herman is worrying about.

I gloss over whether this is LIte, DL or Full - minor changes would need to 
tbe made ...

1) the documentation states that the supported datatypes are xsd:integer and 
xsd:string.

2) On input any typed literal of type rdf:XMLLiteral is verified. It is 
checked that the lexical form is in the lexical space (this is a no op for 
rdf:parseType="Literal", a simple way to verify this for   ohter input is to 
synthesis an RDF/XML document with hopefully a single rdf:parseType="Literal" 
triple in, and parse it - Jena includes working code using this algorithm)

3) Any rdf:XMLLiteral literal that is not in the lexical space is rejected 
(not quite sure what happens, detail)

4) a complete OWL reasoner supporting the given datatypes is used.

5) The reasoner can find all RDF entailments which follow from 
rdf:XMLLiteral's which have the same lexical form, but cannot conclude that 
two with different lexical forms are different. Since no RDFS entailments 
follow from this (such reasoning is part of  OWL), the reasoner does find all 
RDFS entailments

6) by hypothesis the reasoner finds all OWL entailments



I believe such an implementation could justifiably claim RDFS conformance and 
OWL conformance.  

===

While there is a blemish in the mismatch between the semantics docs it is not 
a showstopper. In my opinion Herman is making too much of this.

(the observation about datatype theory/map is a plausible editorial change to 
test)


Jeremy
Received on Monday, 15 December 2003 03:09:30 GMT

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