Custom Query (733 matches)

I tried to compile sage on my ARM-based notebook, and failed with the attached build log.

This is part of : trac.sagemath.org/sage_trac/ticket/10285 (I had to leave h t t p : / / out because it makes my report look too spamish)

Hello Singular Team,

I have played a bit with different definitions of G-Algebras, and I noticed something that is confusing:

> LIB "./ncfactor.lib"; 
> ring R = (0,q),(x,d),dp;
> def r = nc_algebra(1/q,1);
> setring r;
> basering;
//   characteristic : 0
//   1 parameter    : q
//   minpoly        : 0
//   number of vars : 2
//        block   1 : ordering dp
//                  : names    x d
//        block   2 : ordering C
//   noncommutative relations:
//    dx=1/(q)*xd+1
> ring S = (0,q),(a(1..2),b(1..3)),dp;
> basering;
//   characteristic : 0
//   1 parameter    : q
//   minpoly        : 0
//   number of vars : 5
//        block   1 : ordering dp
//                  : names    a(1) a(2) b(1) b(2) b(3)
//        block   2 : ordering C
> def W = r + S;
// ** Not defined: Cannot map a rational fraction and make a
polynomial out of it! Ignoring the denumerator.
> setring W; basering;
//   characteristic : 0
//   1 parameter    : q
//   minpoly        : 0
//   number of vars : 7
//        block   1 : ordering dp
//                  : names    x d
//        block   2 : ordering dp
//                  : names    a(1) a(2) b(1) b(2) b(3)
//        block   3 : ordering C
//   noncommutative relations:
//    dx=x*d+1

As you see, the non-commutative relation gets messed up when trying to add r to S. I discussed this behaviour with Viktor Levandovskyy, and he confirmed that this is unexpected. Somehow, the objects in the two subrings are not mapped properly.

LIB "ncall.lib"; ring r=2,(x,y,z),dp; ring s=0,(a,b,c,d),dp; def nc_s=SuperCommutative?(3,4); def R=r+nc_s; setring R; R;

characteristic : 2 number of vars : 7 block 1 : ordering dp : names x y z block 2 : ordering dp : names a b c d block 3 : ordering C noncommutative relations: quotient ring from ideal _[1]=d2 _[2]=c2

def X=nc_s+r;

Error on recognizing nc types

setring X; X;

characteristic : 2 number of vars : 7 block 1 : ordering dp : names a b c d block 2 : ordering dp : names x y z block 3 : ordering C noncommutative relations: quotient ring from ideal _[1]=d2 _[2]=c2

Sowohl R=r+nc_s als auch X=nc_s+r haben das zu erwartende Ergebnis, aber bei letzterem gibt es Error on recognizing nc types

Ist diese Fehlermeldung ein Fehler? Oder ist es wirklich nicht erlaubt, nc_s+r zu sagen (warum?), waerend r+nc_s problemlos geht?