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Re: ACTION 2001-08-24#9 : issues with containers

From: Jan Grant <Jan.Grant@bristol.ac.uk>
Date: Mon, 3 Sep 2001 17:04:36 +0100 (BST)
To: Dan Connolly <connolly@w3.org>
cc: Brian McBride <bwm@hplb.hpl.hp.com>, pat hayes <phayes@ai.uwf.edu>, w3c-rdfcore-wg <w3c-rdfcore-wg@w3.org>
Message-ID: <Pine.GSO.4.31.0109031655310.10866-100000@mail.ilrt.bris.ac.uk>
On Mon, 3 Sep 2001, Dan Connolly wrote:

> Again, suppose the graph had a Bag rather than an Alt:
>
>       <doc1> <dc:creator> _:a .
>       _:a <rdf:type> <rdf:Bag> .
>       _:a <rdf:_1> <jan> .
>       _:a <rdf:_2> <dan> .

I don't consider the two to be interchangable. Why? Compare

	http://ioctl.org/rdf/ms/rdfms#108
"The students in course 6.001 are Amy, Tim, John, Mary, and Sue."
It seems here that the collection itself is truly considered the value
of a property, whereas...

	http://ioctl.org/rdf/ms/rdfms#111  (and #112)
"Here, any one of the items listed in the container value for
DistributionSite is an acceptable value without regard to the other
items."

In other words, the Alt-collection itself isn't really being considered
the value of the property; the members of the Alt are being considered
so instead.*

> We don't license the inference that
> 	<doc1> <dc:creator> <jan>.
> in that case, do we? No. Then why should rdf:Alt have any magic
> associated with it?

Because clearly they don't behave in the same way, so the analogy isn't
sound.

I'd rather see Alt go away - the examples in M+S are vague and subject
to this kind of confusion.

jan

* although there are two kinds of alternative notion: the one in this
example is "this is true for ever member of the Alt, just pick one" (so
why isn't it just a bag?) as opposed to "this is true for at least one
member of the alt" - which is where you need some MT support (I think).


-- 
jan grant, ILRT, University of Bristol. http://www.ilrt.bris.ac.uk/
Tel +44(0)117 9287088 Fax +44 (0)117 9287112 RFC822 jan.grant@bris.ac.uk
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Received on Monday, 3 September 2001 12:06:31 EDT

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