Re: please check this

[Karim Belabas <Karim.Belabas@math.u-bordeaux.fr>]

The root cause was 

? gcd(x/2, 1/(2*x))
%1 = 1/(4*x)

The problem is now fixed in the master branch.

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/

* Remigiusz Leon Suwalski [2025-03-30 01:15]:
> Hi,
> I discovered with git-bisect that the regression has been probably intoduced here:
> https://pari.math.u-bordeaux.fr/cgi-bin/sgitweb.cgi?p=pari.git;a=commitdiff;h=a4113027d04815ddc04d111db7a6620f4a8ab7aa
> 
> a4113027d04815ddc04d111db7a6620f4a8ab7aa gives (2*a^2 - 2*b^2)/(4*b*a)
> 183213fc2fc9e2798b1023790ed455ee17eb3c07 gives (a^2 - b^2)/(2*b*a)
> 
> I let people more familiar with the source code to discuss the potential fix.
> 
> Best regards,
> R. Suwalski
> 
> On Sunday, March 30th, 2025 at 00:01, American Citizen <website.reader3@gmail.com> wrote:
> 
> > owner@localhost:~/math/cuboids> gp
> > 
> > Reading GPRC: /home/owner/.gprc
> > GPRC Done.
> > 
> > GP/PARI CALCULATOR Version
> > 2.18.1 (development git-1fa1ee045f)
> > amd64 running linux
> > (x86-64/GMP-6.3.0 kernel) 64-bit version
> > compiled: Mar 29 2025, gcc
> > version 13.3.0 (SUSE Linux)
> > threading engine: single
> > (readline v7.0
> > enabled, extended help enabled)
> > 
> > Copyright (C)
> > 2000-2025 The PARI Group
> > 
> > PARI/GP is free software, covered by the GNU General Public License, and
> > comes WITHOUT ANY WARRANTY WHATSOEVER.
> > 
> > Type ? for help, \q to quit.
> > Type ?18 for how to get moral (and possibly technical) support.
> > 
> > parisizemax = 10000003072, primelimit = 1048576, factorlimit = 1048576
> > ? chkr1=(a^2-b^2)/(2ab)
> > %1 = (2a^2 - 2b^2)/(4ba)
> > ?
> > What??? where did that extra factor of 2 come from?
> > 
> > While %1 is correct, in extracting the numerator and denominator, things
> > quickly fall apart.
> >