Re: bnfinit in different versions of pari

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

On Tue, Oct 24, 2023 at 10:45:59PM +0000, Jinyue Luo wrote:
> ?  f=x^16 - 8*x^13 - 756*x^12 + 24*x^10 + 3240*x^9 + 568620*x^8 - 32*x^7 - 3888*x^6 - 314928*x^5 - 2204480*x^4 + 864*x^3 + 34992*x^2 + 629856*x + 8503056;
> ?  F=bnfinit(f,1);
> ? F[8][5]
> %3 = [;]
> 
> When I did it in pari 2.15.3 & pari 2.13.3, I will get the output [;]. But in pari 2.11.2, the output is the fundamental units I want.
> 
> ?  bnf=bnfinit(x^6+x-1,1);
> ? bnf[8][5]
> %5 = [-x^5 - 1, -x^5 - x^4 + x - 1, -x^5 - x^3 - 1]
> 
> This will also work for smaller fields in pari 2.15.3 & pari 2.13.3 as the codes above.
> 
> How could I fix it?

Use F.fu instead of F[8][5], this will work will all version.

Cheers,
Bill