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Re: lists and other facts and rules in RDF

From: Dan Connolly <connolly@w3.org>
Date: Sat, 12 Aug 2000 20:13:04 -0500
Message-ID: <3995F620.367D216A@w3.org>
To: jos.deroo.jd@belgium.agfa.com
CC: " - *www-rdf-interest@w3.org" <www-rdf-interest@w3.org>
jos.deroo.jd@belgium.agfa.com wrote:
> 
> Dan,
> 
> While at Disneyland Paris I couldn't stop thinking about your
> cool list stuff at http://www.w3.org/2000/07/hs78/lists and also
> about the problem of expressing other facts and rules in RDF.
> 
> We have the following assertions
> [var:X e:in [var:X e:list var:B]]
> [[var:X e:in [var:A e:list var:B]] e:if [var:X e:in var:B]]

I have come to accept the practice of identifying variables
in RDF by string prefix matching, but I don't believe there's
any cause for making a new URI scheme for them. Please
stake out a portion of URI space that you own for this purpose,
such as

ftp://windsor.agfa.be/outgoing/RCEI/NET/euler/variable#*

so in stead of the URI var:x , write

ftp://windsor.agfa.be/outgoing/RCEI/NET/euler/variable#x

I have claimed a portion of URI space for variables:

	http://www.w3.org/2000/07/hs78/KIF?indvar=
	(cf http://www.w3.org/2000/07/hs78/KIF )

Note that the semantics of a variable are tied up with
the whole semantics of the logic they're used in.
But if your logic is consistent with KIF (and there's
a good chance it is) then by all means, use these URIs.

There's no problem using var: as a namespace prefix.
But please don't go around using unregistered URI schemes
without really good reasons.

More on the rest of your proof stuff when I manage
to study it further, I hope...


> [1] ftp://windsor.agfa.be/outgoing/RCEI/NET/euler/index.html

-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Saturday, 12 August 2000 21:13:39 GMT

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