Re: Component [5] of prime ideal structure

[Jeroen Demeyer <jdemeyer@cage.ugent.be>]

On 2014-02-11 14:07, Bill Allombert wrote:
> On Tue, Feb 11, 2014 at 11:33:48AM +0100, Jeroen Demeyer wrote:
> > Consider
> >
> > gp> idealprimedec(nfinit(x^2+1), 5)[1][5]
> > %4 =
> > [2 -1]
> >
> > [1  2]
> >
> > What is the meaning of this? The documentation ??idealprimedec says
> > that it is supposed to be an algebraic integer, but I don't
> > understand
>
> Try idealprimedec(nfinit(x^2+1), 5)[1][5][,1]

This doesn't work for

gp> idealprimedec(nfinit(x^2+1), 3)[1][5]
%1 = 1

One could of course easily wrap this in a (member) function.

The libPARI documentation clearly explains that the result is a 
zk_scalar_or_multable, but this is not in the users manual ??idealprimedec.