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Re: Strategies for inference over lists of values

From: Drew McDermott <drew.mcdermott@yale.edu>
Date: Mon, 22 Mar 2004 17:51:49 -0500 (EST)
Message-Id: <200403222251.i2MMpns2007514@pantheon-po04.its.yale.edu>
To: www-rdf-logic@w3.org

> > > [Graham Klyne]
> > > I'm wondering what strategies folks are using for inference over
> > > collections (lists) of values in RDF (other than resorting to ad-hoc
> > > code).  (Maybe also over containers, but the closure of lists makes the
> > > problem easier to define.)
> >
> [me]
> >What do you mean by "strategy"?  Can you give an example of ad-hoc
> >code?  Are we allowed to use OWL Rules?
> [Graham Klyne]
> By "strategy", I mean here something like the outline of a general 
> technique that can be used in a variety different situations.  Jos' 
> response of using recursive rules in his backward-chaining reasoner, Euler 
> [4], is an example.  An approach using OWL rules (or a pattern based on 
> such) would indeed be interesting to me.
> 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.

Whether you use 'fold' or recursive rules, at some point you're going
to need an 'eval' operation that enables you to invoke actual
procedures that compute things.  ('+', for instance).  For 'fold' to
be anything like universal you're going to need higher-order
functions, which would be a breathtaking addition to SWRL and other
deductive systems.

So, have you thought about what the 'eval' sublanguage would contain?

                                             -- Drew

                                   -- Drew McDermott
                                      Yale Computer Science Department
Received on Monday, 22 March 2004 17:52:02 UTC

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