Singular
https://www.singular.uni-kl.de/forum/

atkins.lib ist not usable.
https://www.singular.uni-kl.de/forum/viewtopic.php?f=10&t=2953
Page 1 of 1

Author:  OleksandrIenaUnregistered [ Sat Jun 19, 2021 12:47 pm ]
Post subject:  atkins.lib ist not usable.

Output of "example Atkin;" from "atkins.lib";
Code:
>example Atkin;
// proc Atkin from lib atkins.lib
EXAMPLE:
    ring R = 0,x,dp;
    Atkin(7691,100,5);
-1
    Atkin(3473,10,2);
-1
    printlevel=1;
    Atkin(10000079,100,2);
Set i = 0, n = 0 and N(i) = N(0)= 10000079.
pause>

List H of possibly suitable discriminants will be calculated.
H = -3,-4,-7,-8,-11,-12,-15,-16,-19,-20,-23,-24,-27,-28,-31,-32,-35,-36,-39,-40,-43,-44,-47,-48,-51,-52,-55,-56,-59,-60,-63,-64,-67,-68,-71,-72,-75,-76,-79,-80,-83,-84,-87,-88,-91,-92,-95,-96,-99,-100,-103,-104,-107,-108,-111,-112,-115,-116,-119,-120,-123,-124,-127,-128,-131,-132,-135,-136,-139,-140,-143,-144,-147,-148,-151,-152,-155,-156,-159,-160,-163,-164,-167,-168,-171,-172,-175,-176,-179,-180,-183,-184,-187,-188,-191,-192,-195,-196,-199,-200
pause>

N(0) = 10000079 is divisible by 5.
pause>

N(0) = N = 10000079 and therefore N is not prime.
pause>

-1

>


In particular 10000079 should be a prime number, the message "10000079 is divisible by 5" is noncence.

The reason for the problem is the usage of "a mod b" with number type.
Code:
> ring r =0, x, dp;
> 10000079 mod 5;
4
> number(10000079) mod 5;
0
>

I suppose the problem with the library exists since years.
:(

Author:  hannes [ Wed Jul 14, 2021 8:39 pm ]
Post subject:  Re: atkins.lib ist not usable.

atkins.lib is now removed

Page 1 of 1 All times are UTC + 1 hour [ DST ]
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
http://www.phpbb.com/