On Fri, 18 Jul 2008 22:39:01 +0100, Jack <jj@[EMAIL PROTECTED]
>
wrote in <news:F38gk.6608$7B3.2197@[EMAIL PROTECTED]
> in
alt.algebra.help:
> I've decided that zero and negative integers could be
> useful to me. All negative integers are divisible by
> positive integers (if, on occasions, only themselves and
> -1), aren't they?
Every negative integer other than -1 is divisible by at
least *two* positive integers. Specifically, if n is a
negative integer different from -1, then n is divisible by
the positive integers 1 and -n. For n, m in Z, the notation
n | m (m is divisible by n) simply means that there is some
integer k such that m = kn; k may be positive, negative, or
zero.
> Should I, then, stick with |N, but define it as 'all
> integers',
Absolutely not: that would be a serious and very confusing
violation of convention.
[...]
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