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Re: How does RDF/OWL formalism relate to meanings?

From: Graham Klyne <GK@ninebynine.org>
Date: Tue, 13 Apr 2004 11:36:39 +0100
Message-Id: <5.1.0.14.2.20040413113534.00bb8ce0@127.0.0.1>
To: Dan Brickley <danbri@w3.org>
Cc: public-sw-meaning@w3c.org

At 00:45 10/04/04 -0400, Dan Brickley wrote:
>Literal-valued properties, as well as URI-valued properties (and for
>that matter, bNode-valued properties, if such scenarios can plausibly be
>concocted).

Seems easy enough:  the person who wrote a book whose title is "Moby Dick" ?

>Yes, I believe (in light of the 3-4 year FOAF experiment) that such a
>disclaimer is appropriate. When we started FOAF there was no class
>owl:InverseFunctionalProperty. Now we have it, but I am not 100%
>convinced the semantics it has (due to the approach we took to
>formalising RDF and OWL) capture entirely what we need for
>reference-by-description. Specifically, OWL allows that the
>property/value pair might match different individuals in different
>interpretations, and guarantees "at most one"-ness only with regard to
>a single interpretation. In FOAF, I say that properties such as
>foaf:mbox and foaf:homepage are "Static inverse functional properties",
>as a (not yet formalised) way of claiming that they cannot take
>different values at different times. If you believe "a1 foaf:homepage
>d2", you should not be prepared to believe a2 foaf:homepage d2" at a
>later date. I don't believe these issues are fully explored yet, so am
>wary of sending an "OWL solves this once and for all" message.

Also, even within a single interpretation, it is common enough in 
real-world usage to depend on uniqueness of a combination of properties;  e.g.
   The person whose name is ...
              who resides at ...
              whose date of birth is ...

I'm not aware of an OWL construct that achieves this.  (Or am I missing 
something?)

#g


------------
Graham Klyne
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Received on Tuesday, 13 April 2004 07:04:26 GMT

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