*Axiom 2.1.* 0 is a natural number ]]>

With this in mind, the responses to your points are the following:

1). Terry does not consider 0 a natural number.

2). I don’t see why 0 playing an important role should mean it is a natural number.

3). The example you provided seems more like an exception.

“Natural numbers have no zero divisors” should read “Positive natural numbers have no zero divisors”. ]]>

*[Corrected, thanks – T.]*

*[Corrected, thanks – T.]*