Date: Sep 18, 1999 8:45 AM
Author: Peter Percival
Subject: Re: -1 x -1 ?





Dale Henderson wrote:

> In article <937516347.13527.0.nnrp-14.c2debf68@news.demon.co.uk>,
> "Guillermo Phillips" <Guillermo.Phillips@marsman.demon.co.uk> wrote:

> > Hello All,
> >
> > Here's something I've always wondered (perhaps in my naivety). Why
> > should -1 x -1 = 1?
> > I appreciate that lots of nice things come from this, but what's the
> > fundamental reason for it?
> >
> > Guillermo.
> >
> >

>
> I've seen a few proofs on this thread that make unfounded assumtions.
> One assumes the uniqness of inverses and another assumes 0x=0.


<cut>

Well, we won't get far without "unfounded assumptions" will we? I assumed
we were working in a ring in which my "unfounded assumptions" do hold.

<cut>I've tried to assume only the axioms of a Ring...