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Re: Enumeration in RDF?

From: Garret Wilson <garret@globalmentor.com>
Date: Tue, 16 Sep 2003 18:58:26 -0700
Message-ID: <3F67BFC2.9080801@globalmentor.com>
To: Benja Fallenstein <b.fallenstein@gmx.de>
Cc: Dan Brickley <danbri@w3.org>, Art.Barstow@nokia.com, www-rdf-interest@w3.org

>> Dan Brickley wrote:
>>> http://www.w3.org/TR/rdf-schema/#ch_collectionvocab
>>> The rdf:List collections mechanism allows the members of a list to be 
>>> enumeated in a way that makes it clear the whole list has been
>>> represented.

 > Garret Wilson wrote:
>> But as one can always add an infinite number of rdf:first properties 
>> to any rdf:List resource (see your citation about), does this really 
>> help ensure that nothing more is added to a list---or even, as you put 
>> it, "makes it clear the whole list has been represented?"

Benja Fallenstein wrote:
> While the RDF semantics do not define this (because they don't deal in 
> cardinalities), it is sensible to interpret rdf:first and rdf:rest to 
> have a cardinality of one. (I don't know whether OWL actually specifies 
> this.)
[...]
> I.e., with rdf:List, you know that there cannot be additional rdf:first 
> or rdf:rest triples "somewhere out there" that change the elements of 
> the list.

That might solve our problem, but that's not RDF. At the reference cited 
by Dan (above), the RDFS specification clearly says:

"RDFS does not require that there be only one first element of a 
list-like structure, or even that a list-like structure have a first 
element."

I therefore do *not* know whether "somewhere out there" there exist 
additional rdf:first triples that add elements to my rdf:List.

Garret
Received on Tuesday, 16 September 2003 21:59:35 GMT

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