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Re: Strategies for inference over lists of values

From: Graham Klyne <GK@ninebynine.org>
Date: Mon, 08 Mar 2004 16:59:11 +0000
Message-Id: <5.1.0.14.2.20040308165407.00bb2bf0@127.0.0.1>
To: "Jeff Z. Pan" <pan@cs.man.ac.uk>, <www-rdf-logic@w3.org>

At 08:48 08/03/04 +0000, Jeff Z. Pan wrote:

>Hi Graham,
>
> > One of the reasons I asked this question was that I have been trying
>to
> > combine some datatype-specific deductions (integer arithmetic)
>expressed in
> > a scheme [1] inspired by the Pan/Horrocks paper [2], with
>collections
> > (lists) of data which are antecedent facts for the desired composite
>rule
> > of deduction.  I am finding that it is surprisingly awkward to use
>the
> > generalized restriction for this purpose, and think that I am
>probably
> > missing a trick here.
>
>I am not sure I get your point here. Could you give an example to show
>why it is hard to use the generalised restriction please?

Jeff,

There are two examples in my previous message at:
   http://lists.w3.org/Archives/Public/www-rdf-logic/2004Feb/0045.html
for which Jos has provided quite straightforward Euler solutions in:
   http://lists.w3.org/Archives/Public/www-rdf-logic/2004Feb/0046.html
using a conventional rule form with special properties, ala CWM.

These examples don't, of themselves, show why it's hard to use the 
generalised restriction.  But they are examples for which I haven't figured 
out an easy way to use it.

#g
--

> >My own experiments suggest that I must combine the
> > restriction with a more conventional (antecedent=>consequent) form
>of rule.
> >
> > The (half-baked) idea I was considering as a way to deal with
>inference
> > over a collection was to introduce a primitive along the lines of a
>'fold',
> > as found in functional programming languages (which has been shown
>to have
> > some degree of universality for expressing recursive/repetitive
>functions
> > [3]), and combine that with non-iterative/non-recursive inference
>patterns.
> >
> > #g
> > --
> >
> > [1]
> >
>http://www.ninebynine.org/RDFNotes/RDF-Datatype-inference.html#sec-choice-constraint-classes
> >
> > [2] Horrocks, I. and J. Pan, "Web Ontology Reasoning with Datatype
>Groups",
> > 2003.
> >
>http://www.cs.man.ac.uk/~horrocks/Publications/download/2003/PaHo03a.pdf
> >
> > [3] J. Functional Programming 1 (1): 1-000, January 1993
> > c fl 1993 Cambridge University Press 1
> > A tutorial on the universality and expressiveness of fold
> > Graham Hutton University of Nottingham
> > (also at http://www.cs.nott.ac.uk/~gmh/fold.pdf)
> >
> > [4] http://www.agfa.com/w3c/euler/
> >
> >
> >
> > ------------
> > Graham Klyne
> > For email:
> > http://www.ninebynine.org/#Contact
> >
> >

------------
Graham Klyne
For email:
http://www.ninebynine.org/#Contact
Received on Monday, 8 March 2004 12:00:01 GMT

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