> 0 is a whole number, whole numbers are non-negative
 > integers....

    It's nice to be so definite, Jasen. 1, 0, and -1 are lots of things. :-)

 > probably I should have said "natural number" =
 > positive integer.
 > (or counting number, 1,2,3... )
 >

    So ... real numbers, like pi or e or the golden mean, are somehow unnatural? :-)

    Somebody remind me ... what's the Ackerman angle? Something to do with
steering geometry, isn't it? It came up yesterday at Newmarket races. :-)

Best wishes,
Bill.

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