Re: [Bug-apl] Modulo or residue function is not generating consistent complete residue systems for some arguments

[Xiao-Yong Jin]

I guess APL standard is really bad in this regard.
Dyalog APL gives the following:

Dyalog APL/S-64 Version 15.0.27700
Unicode Edition
Tue Jun 20 10:46:08 2017
      5J3|14J5
1J4
      5J3|1J4
¯4J1
      5J3|¯4J1
¯4J1

which coincides with the previous gnu apl result.
> On Jun 20, 2017, at 3:02 AM, Jay Foad <address@hidden> wrote:
> 
> With the demo version of APL2 I get:
> 
>       5J3 ∣ 14J5
> ¯4J1
>       5J3 | 1J4
> ¯4J1
>       5J3 | ¯4J1
> ¯4J1
> 
> Jay.
> 
> On 19 June 2017 at 18:03, Frederick Pitts <address@hidden> wrote:
> Jürgen,
> 
>         With gnu apl (svn 961 on Fedora 25, Intel(R) Core(TM) i7-6700
> CPU), the residue function (∣) yields the following:
> 
>       5J3 ∣ 14J5
> 1J4
>       5J3 | 1J4
> ¯4J1
>       5J3 | ¯4J1
> ¯4J1
> The above result means that two elements in the complete residue system
> (CSR) for mod 5J3 are equal, i.e. 1J4 = ¯4J1 mod 5J3, which is not
> allowed.  None of the elements of a CSR can be equal modulo the CSR's
> basis.
> 
> Regards,
> 
> Fred
> 
>