Re: qfbpowraw

[Bill Allombert <allomber@math.u-bordeaux.fr>]

On Mon, Sep 15, 2003 at 06:20:19PM +0200, Karim BELABAS wrote:
> On Mon, 15 Sep 2003, Bill Allombert wrote:
> 
> > On Sun, Sep 14, 2003 at 04:39:07PM +0200, Karim BELABAS wrote:
> > > On Sun, 14 Sep 2003, Bill Allombert wrote:
> > > > It seems that PARI * and ^ operators allow operation on quadratic
> > > > forms but reduce them. I would personnaly prefer it does not reduce
> > > > them.
> > >
> > > Coefficient explosion would occur for ^.
> >
> > ...only if you plan to reduce the result.
> 
> I don't understand this.

I was trying to say that if you want the powraw result the coefficient
explosion is unavoidable, so cannot be accounted as a limitation.

> Currently, if you want no reduction, you use xxxraw routines, whereas the
> natural operators (*, ^) do reduce.

... do reduce sometimes, yes.

> With your proposed change (which I don't like), the natural operators would
> not reduce and you would need to apply reduction yourself if you want it.
> Except that for ^ it's not possible to do this at the proper place [ you can
> only reduce at the end, not after each composition ].
> 
> > Please note that the == operator is not consistent with this
> > policy, nor is ^1.
> 
> It is, assuming all inputs are reduced [ at least for t_QFI ]

Which is not exactly the same as ``do reduce''

Anyway, we must make results more consistent toward reduction one way
or another.

Cheers,
Bill.