[plt-scheme] Natural numbers

From: Carl Eastlund (carl.eastlund at gmail.com)
Date: Wed Mar 11 21:10:37 EDT 2009

On Wed, Mar 11, 2009 at 8:33 PM, Norman Gray <norman at astro.gla.ac.uk> wrote:
> Greetings.
> On 2009 Mar 11, at 23:47, Matthias Felleisen wrote:
>> Natural numbers are the counting numbers. You count how many things you
>> have. (The philosophical way to understand "five" is to say that it is what
>> all collection of five objects have in common.)
>> The natural (sorry) place to start counting is with 0, having nothing.
> In maths, the term "the natural numbers" refers specifically to the set of
> positive integers (see for example [1]), and not to any set isomorphic to
> that.  Thus it does not depend on what you or I may or may not find natural,
> and its meaning is not really a matter for dispute.  Anyone who refers, in
> any sort of semi-formal context, to "the natural numbers" as meaning
> anything other than {n in Z : n > 0} is being quixotic.
> I don't believe computer scientists have a get-out-of-jail-free card here.
> Best wishes,
> Norman
> [1] http://eom.springer.de/N/n066090.htm

The very reference you provide lists an alternate interpretation of
natural numbers including 0 under "comments" at the bottom of the

Carl Eastlund

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