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Re: nature of anon resource [was Re: log:forSome]

From: <jos.deroo.jd@belgium.agfa.com>
Date: Tue, 26 Jun 2001 23:58:03 +0100
To: phayes@ai.uwf.edu
Cc: w3c-rdfcore-wg@w3.org
Message-Id: <OF5E4CC848.A4617E8D-ON41256A76.007A0E41@bayer-ag.com>

>>that's indeed a very good point about skolemization
>>in the case that 'we are not in the scope of a universal
>>quanitifer' we have indeed a full blown *constant*
>>but I think that in general you can not make that
>>assumption (your piece of RDF *could* fall in the
>>scope of many univerally quantified variables (I mean
>>when used by outside-core things)
>WHAT??!!!???? How??? (How can anything outside a document project a
>quantifier scope across that document??)
>That is an amazing idea, and suggests an entirely new picture of how
>the semantic web might work, but if we really think this is possible
>then we should get it clear ASAP, as it completely changes the ground
>rules. For example there is no such thing as an assertion, since
>anything might be only a subexpression of something outside the

A SAP would help here (such a hot weather...)

OK, let's take e.g. the following piece of RDF
(which is at http://www.agfa.com/w3c/n3/ext.n3)

:s0 :is [ :p1 :o1; :p2 :o2].
:s0 :p3 :o3.

and onother one (which is at http://www.agfa.com/w3c/n3/ext-rules.n3)

  {{:u :is [ :p1 :x; :p2 :y]. :u :p3 :z} log:implies
{:u :is [ :p1 :x; :p2 :y; :p3 :z]}} a log:Truth; log:forAll :u, :x, :y, :z.

then the query (which is at http://www.agfa.com/w3c/n3/ext-query.n3)

{:s0 :is :z} log:forSome :z.

will result in (which is at http://www.agfa.com/w3c/n3/ext-result.n3)

 {:s0 :is [ :p1 :o1; :p2 :o2].
  :s0 :p3 :o3} log:implies
{:s0 :is [ :p1 :o1; :p2 :o2; :p3 :o3]}.

:s0 :is [ :p1 :o1; :p2 :o2].

so there is some kind of changed 'extension of objects'
(there must be some link with SKIF here)

OK, we have identified an anonymous node by its content
in the sense of
  a (not *the*) thing which has as 'least common'
  certain descriptions
and it is kind of 'by value' (not 'by reference')
but is that a problem?

Jos De Roo, AGFA http://www.agfa.com/w3c/jdroo/
Received on Tuesday, 26 June 2001 17:58:12 UTC

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