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Re: Before we go on...

From: Patrick Stickler <patrick.stickler@nokia.com>
Date: Fri, 19 Apr 2002 14:13:43 +0300
To: ext Jos De_Roo <jos.deroo.jd@belgium.agfa.com>
CC: Pat Hayes <phayes@ai.uwf.edu>, RDF Core <w3c-rdfcore-wg@w3.org>
Message-ID: <B8E5D697.137C4%patrick.stickler@nokia.com>
On 2002-04-19 11:05, "ext Jos De_Roo" <jos.deroo.jd@belgium.agfa.com> wrote:


> and now I would think we have
> 
> //////
> rdfd:Datatype a rdfs:Class; rdfs:subClassOf rdf:Property .
> rdfd:dcrange a rdf:Property; rdfs:domain rdf:Property; rdfs:range
> rdfd:Datatype.
> rdfd:lex a rdf:Property; rdfs:domain rdfs:Resource; rdfs:range rdfs:Literal .
> 
> { ?d a rdfd:Datatype } log:implies { ?d rdfs:domain ?d } .

Fine up to here.

> { ?d a rdfd:Datatype . ?o ?d ?l } log:implies { ?o rdfd:lex ?l } .

Well, yes. But I think this is better captured by

{ ?d a rdfd:Datatype } log:implies { ?d rdfs:subPropertyOf rdfd:lex } .

> { ?p rdfd:dcrange ?d . ?o rdfd:lex ?l . ?s ?p ?o } log:implies { ?o ?d ?l } .

Fine, insofar as this is expressing the equivalence of the lexical
form and datatype property idioms.

I would also add:

{ ?p rdfd:datatype ?d . ?s ?p ?l . ?l rdf:type rdfs:Literal }
   log:implies { ?s ?p ?o. ?o ?d ?l } .

Note that this latter entailment is *not* changing the meaning
of the literal ?l. Rather, it is making explicit the value that is
identified by the combination of the inline idiom and the rdfd:datatype
assertion.

Now, I still have a problem with the closure rules saying "add
the following to the graph". Rather, an application can take the
'then' portion of the closure rules as being "understood" as
part of the datatyping interpretation, without having to actually
assert those implied statements in the graph. I'd like to change
the table headings of the closure rules to "If the graph contains"
and "then one may infer" and not actually say that statements
should be added to the graph explicitly.

Patrick

--
               
Patrick Stickler              Phone: +358 50 483 9453
Senior Research Scientist     Fax:   +358 7180 35409
Nokia Research Center         Email: patrick.stickler@nokia.com
Received on Friday, 19 April 2002 07:10:52 EDT

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