# [plt-scheme] Natural numbers

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
--
Norman Gray : http://nxg.me.uk
Dept Physics and Astronomy, University of Leicester