Bug or Feature?

[Gonçalo Rodrigues]

On Tue, 25 Nov 2003 16:04:57 +0100, Stephan Diehl
<stephan.diehlNOSPAM at gmx.net> wrote:

[snip]

>
>You might have noticed, I was talking about Mathematics, not the imperfect
>implementation of it in computers :-)
>To have division as a meaningfull operation, the set in question must be a
>group under the '*' operation (See for example
>"http://en2.wikipedia.org/wiki/Group_(mathematics)" )
>The point is, that division is the reverse operation to multiplication.

But when talking of "numbers" a group is not enough, you want a field
- a set with two operations (in some situations something weaker, like
integral domains, is enough). In fields, such as real numbers, complex
numbers, p mod integers, p-adic fields, etc. every number has a
multiplicative inverse *except* the zero.

Pedantically yours,
G. Rodrigues