Re: polredabs() again

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

On Fri, Apr 04, 2003 at 12:18:34AM +0200, Karim BELABAS wrote:
> On the other hand, the current specification of polredabs is quite useless.
> There's no application whatsoever for a "polynomial of absolute smallest
> T2-norm". It's not even guaranteed to have minimal discriminant, or to
> yield smallest coefficients. The only one I can see is to give a
> pseudo-canonical representative for the field (this helps table builders,
> less isomorphism tests...)

I do not fully agree. Having a canonical defining polynomial is quite
useful when you are generating lots of (small) isomorphic files (try
galoisubfields on a large non abelian Galois groups).

On the other hand, the polred specification that return a more or less
random list of polynomials that may or may not map all subfields, and
may or may not be smaller than the input, could benefit from an 
improvement.

But anyway, it is just an interface issue.

Cheers,
Bill.