W3C home > Mailing lists > Public > www-rdf-logic@w3.org > May 2001

Re: What do the ontologists want

From: David Allsopp <dallsopp@signal.dera.gov.uk>
Date: Fri, 18 May 2001 10:36:36 +0100
Message-ID: <3B04ED24.FFDB28C7@signal.dera.gov.uk>
CC: www-rdf-logic@w3.org

pat hayes wrote:
> ...the problem is not being able to say
> all these good things about assertions: it is that triples (alone)
> are not adequate to be the assertions. They are too SMALL. They don't
> let me say what I want to be able to say: they don't let me say (NOT
> ...)  or (... OR ....) or (EVERY .... IS ....). These kinds of
> assertions need more than single triples, you see, because they have
> more than three parts. A simple point, surely? (And please don't tell
> me that you can do this with "reification". I know, I know: read on.)

Ah, light dawns - that clears up my questions in yesterdays email too;
thank you.

So the RDF dilemma is that either A) we stick to very trivial things
expressible with single triples
or B) attempt to feed an inference engine a mixture of assertions and
syntactic sugar, and watch it choke...8-)

> Now, you can always take one of these more-than-triple things and
> hack up a structure of triples to encode it, sure. So in a sense you
> can think of the knowledge as a set of triples, or at least encoded
> in a set of triples. But then that encoding is NOT A LOGICAL
> CONJUNCTION. It is a data-structure which is being used to represent
> a piece of syntax. Again, I have no problem with that either.

> What I do have a problem with is getting these confused with one
> another: with a notation (like RDF) that says that it is just
> conjunctions of triple-style atomic assertions, but also wants to be
> a datastructure language for encoding more complex assertions. You
> can't have it both ways...


David Allsopp.

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Received on Friday, 18 May 2001 05:40:58 UTC

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