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Re: Another try.

From: Guus Schreiber <guus.schreiber@vu.nl>
Date: Wed, 22 Feb 2012 16:38:51 +0100
Message-ID: <4F450C0B.6010106@vu.nl>
To: Pat Hayes <phayes@ihmc.us>
CC: RDF WG <public-rdf-wg@w3.org>
Pat,

Thanks a lot for this. I have one clarification question.

> Here is an example. Suppose we want to archive the states of some graph container called :G which changes daily. Some of the triples in the container are stable, others not: it depends on the property. Then we can have a dataset like this:
>
> :G: { :G01012012 x:ContentsOfOnDay "01012012"^^xsd:date +
> :G01022012 x:ContentsOfOnDay "01022012"^^xsd:date +
> :G01032012 x:ContentsOfOnDay "01032012"^^xsd:date +
> ....  }
> :G01012012: { :this :that :other +
> :this :never :changes .
> ...}
> :G01022012: {:this :that :else +
> :this :never: changes .
> ....|
> ....

I'm not sure I understand this correctly; is the '+' syntax meant to 
show that a triple is instable?

I would be very hesitant to add stuff at the basic triple-syntax/model 
level. And also: is not evrry triple inherently instable (even the first 
sentence of Pride & Prejudice)? We are just often happy to refrain from 
making the context explicit, because in practice it is not needed (or 
better: are happy to rely on the source reference for later 
re-interpretation/refutation).

Guus

>
> The intended semantics of the first graph are that ContentsOfOnDay x y z means that the graph x is the contents of the container z on the day y.  Notice that the URI for the graph container is here used as the first graph label, but what it *refers to* is the container, not that graph. The first graph here is *about* the container, one might reasonably say.
>
> -----
>
> Hope this idea is now reasonably clear.  FWIW, I think that this extension to RDF would be immediately and eagerly seized upon by a large number of users. The need for some kind of 'context' mechanism has been a refrain of RDF critics since 2004.
>
> Pat
>
> [1] http://journalofwebsemantics.blogspot.com/2012/02/jws-special-issue-reasoning-with.html
>
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Received on Wednesday, 22 February 2012 15:39:25 GMT

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