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RE: what RDF is not (was ...)

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Fri, 04 Jan 2002 11:56:04 -0500
To: Mark.Birbeck@x-port.net
Cc: bdehora@interx.com, www-rdf-interest@w3.org
Message-Id: <20020104115604S.pfps@research.bell-labs.com>
From: Mark Birbeck <Mark.Birbeck@x-port.net>
Subject: RE: what RDF is not (was ...) 
Date: Fri, 4 Jan 2002 15:38:29 -0000 

> Thanks Bill ... I think! I didn't realise that there were larger and smaller
> infinities!
> 
> But if there is a [...] number:
> 
> 	.6775746636352
> 
> I still don't understand why we can't we have a URI:
> 
> 	http://www.schema.org/datatypes/natural#.6775746636352
> 
> In other words, for every natural number there is a URI.

This works for real numbers with really boring decimal expansions.  You can
even go further and have

	bar:sdddd.eeee.ffff

		for s either + or -
		and dddd,eeee,ffff finite sequences of decimal digts

represent the real number whose integral part is sdddd, and whose
fractional part starts eeee and then repeats ffff infinitely.  This
produces finite representations for all rational numbers.

[...]

> (I don't want to mix up two debates here. I wasn't actually commenting on
> data typing in my initial posting, I was merely asking why Peter was saying
> that there were a finite number of URIs. 

I wasn't saying that there are a *finite* number of URIs, just that every
URI is finite (or can be finitely represented).

I think we may have been talking at
> cross purposes. I am saying that whilst there are of course a finite number
> of URIs at any one time, there are an infinite number of _possible_ URIs.
> The problem is not in finding enough, but in coming up with a convenient way
> of creating them as and when they are needed.)

This is *not* the problem at all.  I'll allow you an infinite number of
URIs that exist right now, just as long as each of them can be finitely
described.

> Mark

peter
Received on Friday, 4 January 2002 11:57:01 GMT

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