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RE: Expressing mathematical relationships in an ontology?

From: Danny Ayers <danny666@virgilio.it>
Date: Fri, 13 Jun 2003 17:38:06 +0200
To: "Roger L. Costello" <costello@mitre.org>, <www-rdf-interest@w3.org>
Message-ID: <BKELLDAGKABIOCHDFDBPKEKMDAAA.danny666@virgilio.it>


> But suppose that I want to express a mathematical relationship.  For
> example, consider these two instances:
>
> Instance 1:
>
>    <Distance>
>       <rdf:value>2.54</rdf:value>
>       <units>centimeters</units>
>    </Distance>
>
> Instance 2:
>
>    <Distance>
>       <rdf:value>1.0</rdf:value>
>       <units>inches</units>
>    </Distance>
>
> It would be nice if this mathematical relationship could be
> declaratively expressed:
>
>     2.54 centimeters = 1.0 inches
>
> What is the recommended practice for expressing such mathematical
> relationships?  I don't want to hardcode them in my application.

d1 math:equals d2 ?

Or to put it another way, hello Pandora's box! For a start you've got the
problem of representing the values - ok, there's XML schema datatypes, but
presumbaly you are talking 'true' values rather than double (or whatever)
precision. To be really useful you'll probably have to bring in the concept
of continuants (as opposed to occurrents, check John Sowa's top level
ontology [1]) with associated logic and define a property corresponding to
arithmetic equivalence to use as above. Having said all that, the problem's
in the description rather than the processing and I'm sure someone's already
done it...

> Is RuleML intended to express such things?  /Roger

I could be wrong, but I don't think so - but I wouldn't put anything past
them ;-)

Cheers,
Danny.

[1] http://users.bestweb.net/~sowa/ontology/toplevel.htm
Received on Friday, 13 June 2003 11:41:34 GMT

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