Re: qfbpowraw

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

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.

Please note that the == operator is not consistent with this
policy, nor is ^1.

> qfb[comp|pow]raw would be dumped then ?

Why ? qfbnucomp/qfbnupow are still available.

> > Lastly, is it possible to get the SL2 matrix involved in the equivalence
> > between two forms ? (I have written a GP script for that effect, but...)
> 
> Not from the current GP interface. In the real case, you have the distance
> component, which is less useful, but remains small.

I will implement that, then. This is necessary to solve binary quadratic
form equation (probably following Gauss, this is a general Cornacchia
like algorithm with probabilistic polynomial running time).

Cheers,
Bill.