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Re: n-ary datatypes

From: Pat Hayes <phayes@ihmc.us>
Date: Wed, 7 Feb 2007 11:27:14 -0600
Message-Id: <p06230908c1efbb9a023c@[10.100.0.26]>
To: hans.teijgeler@quicknet.nl
Cc: public-owl-dev@w3.org

>David,
>Is R3 (coordinates) an example of n-ary datatypes?

It could be. Want to define a suitable datatype? It would be a great 
service. I would suggest convening a working group with at least one 
mathematician, and representatives from several geographical 
communities and manufacturers of GPS equipment. No doubt other people 
can suggest other likely members. It should only take a few years or 
so.

Pat

>Hans
>
>----- Original Message -----
>From: "Turner, David" <davidt@hp.com>
>Date: Tuesday, February 6, 2007 3:19 pm
>Subject: n-ary datatypes
>
>>
>>  Hi,
>>
>>  I've recently started working with Jeremy Carroll at HP, initially
>>  focussing on OWL 1.1. At the moment I'm reading through the specs,
>>  and I
>>  have some questions about n-ary datatypes as implemented in OWL.
>>  Fundamentally, I am having trouble seeing how n can be anything other
>>  than 1.
>>
>>  >From section 5 of [1]:
>>
>>  > This is in order to support class definitions such as "objects
>>  whose
>>  > width is greater than their height", where the values of width
>>  and
>>  > height are specified using two data properties. In such
>>  definitions,
>>  > the arity of the given data range must be equal to the number of
>>  the
>>  > given data properties."
>>
>>  which seems to be the only place in the document that mentions the
>>  possibility of non-1 arities. How, exactly, would one go about
>>  definingthe class of objects whose width is greater than their height?
>>  Presumably the  intention is to have a datatype of arity two, whose
>>  extension is the graph of the relation '>', but I cannot find the
>>  appropriate syntax to define this. I would like to understand how to
>>
>>  (a) define a datatype, arity 2, being the product of the width and
>>  height datatypes, then
>>  (b) restrict this datatype down to those pairs <width, height> where
>>  width > height.
>>
>>  It is not obvious how to do either (a) or (b) within OWL. The
>>  collectionof XML Schema facets seems only to be relevant to unary
>>  datatypes, so is
>>  of no help here.
>>
>>  Cheers,
>>
>>  Dave Turner
>>
>>
>>  (Incidentally, [1] makes the false claim that its canonical version
>>  lives at http://owl1-1.cs.manchester.ac.uk/syntax.html - this link is
>>  broken).
>>
>>  [1] http://owl1_1.cs.manchester.ac.uk/owl_specification.html
>>
>>
>>
>>
>>


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Received on Wednesday, 7 February 2007 17:27:34 GMT

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