Re: bnfisintnorm/bnfisnorm and availability of units

[Charles Greathouse <crgreathouse@gmail.com>]

bnfisintnorm also has issues if you lower the precision to 19 digits. The question then becomes, not why does one need units, but why does one need that at higher precision?

On Tue, Aug 6, 2024 at 1:06 PM Max Alekseyev <maxale@gmail.com> wrote:

Hello,

I'm puzzled by the code example quoted below. Why does bnfisintnorm() run fine, but bnfisnorm() complains about missing units?

I'd assume that units are a prerequisite for both these functions, but it turns out not to be the case. Do I miss something here?

Regards,

Max

===

? s=216145205;
? b=bnfinit(x^2-s);
? bnfisintnorm(b,s-1)
%4 = [-411706627786612628571*x - 6052860449312256784985647, -411706627786612628571*x + 6052860449312256784985647]
? bnfisnorm(b,s-1)
  ***   at top-level: bnfisnorm(b,s-1)
  ***                 ^----------------
  *** bnfisnorm: precision too low in makeunits [cannot get units, use bnfinit(,1)].
  ***   Break loop: type 'break' to go back to GP prompt
break>