Re: equality of t_INTMODs

Hi Karim,

After the fix we have

? Mod(14,20) == Mod(39,55)
%1 = 1

I understand why, but nevertheless it looks very confusing.

Regards,
Max


On Fri, Jan 24, 2025 at 10:58 AM Karim Belabas <
[email protected]> wrote:

> Hi Max,
>
> * Max Alekseyev [2025-01-24 16:12]:
> > In view of a recently discovered issue in Sage (
> > https://github.com/sagemath/sage/issues/39372), I'd like to check how
> the
> > following two (in)equalities co-exist in PARI/GP. Do they violate any
> > design conventions and/or represent a notable exception to those?
> >
> > ? Mod(14,20) == Mod(39,55)
> > %1 = 0
> > ? Mod(14,20) - Mod(39,55) == 0
> > %2 = 1
>
> They do violate the design convention (x == y iff x - y == 0;
> use the === operator for proper equality without implicit coercion).
>
> t_POLMOD had the same issue. Both issues are now fixed in 'master'.
>
> Cheers,
>
>     K.B.
> --
> Pr. Karim Belabas, U. Bordeaux, Vice-président en charge du Numérique
> Institut de Mathématiques de Bordeaux UMR 5251 - (+33) 05 40 00 29 77
> http://www.math.u-bordeaux.fr/~kbelabas/
>