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

From: <herman.ter.horst@philips.com>
Date: Mon, 15 Dec 2003 14:59:24 +0100
To: Jeremy Carroll <jjc@hpl.hp.com>, www-webont-wg@w3.org
Cc: connolly@w3.org, pfps@research.bell-labs.com, pat hayes <phayes@ihmc.us>, sandro@w3.org
Message-ID: <OFB7DB7142.344366C5-ONC1256DFD.004B90DD-C1256DFD.004CE513@diamond.philips.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 ...

I agree, in addition, with Pat's comments that it seems to be necessary to 

correct the test cases to become consistent with S&AS [1].

>
>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

The phrase 'intended meaning' is not completely operational.
If we replace 'intended' by 'expressed', then I agree, and
would add that there is inconsistency between S&AS and
OWL Test, with respect to XMLLiteral.

>
>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.

What would be the place of such an implementation sketch?
Isn't it the task of Webont to produce consistent specs?

>
>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.

I would like to point out that there is no inconsistency between RDF 
Semantics
and OWL S&AS.  There exists an inconsistency between S&AS and OWL Test.
As you noted, tests 201 to 205 would need reconsideration.

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

Herman

[1] http://lists.w3.org/Archives/Public/www-rdf-comments/2003OctDec/0236.html
Received on Monday, 15 December 2003 09:00:07 GMT

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