Opened 10 years ago

Closed 10 years ago

#637 closed bug (fixed)

nc_algebra: additional check needed

Reported by: levandov@… Owned by: Oleksandr
Priority: minor Milestone: 4-1-0 and higher
Component: dontKnow Version: 4-0-0
Keywords: Cc: aheinle@…

Description (last modified by Oleksandr )

It turned out, that nc_algebra either does not check or checks incorrectly whether the nonzero elements in the first argument (structure constants) are invertible. For instance,

ring r = 0,(x,d),dp;
def R = nc_algebra(x^2,0); setring R;

should return an error since x2 is not invertible in r. Instead, just a commutative ring is returned. Tested with both 3-1-7 and 4-0-0. The problem applies to matrices in the first argument as well:

ring r=0,(x,y),dp;
matrix C[2][2]=0,x^2, 0,0;
def R = nc_algebra(C,0); setring R;

Notably, "R;" print commutative R but with the field "noncommutative relations:", that is the attempt of providing R with noncommutative structure has been tried.

Thanks in advance.

Change History (4)

comment:1 Changed 10 years ago by Oleksandr

Owner: changed from somebody to Oleksandr
Status: newassigned

comment:2 Changed 10 years ago by Oleksandr

Description: modified (diff)

i have simplified 2nd test.

Last edited 10 years ago by Oleksandr (previous) (diff)

comment:3 Changed 10 years ago by Oleksandr

i am testing my fixes

comment:4 Changed 10 years ago by Oleksandr

Resolution: fixed
Status: assignedclosed
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