Opened 15 years ago

Closed 15 years ago

Last modified 15 years ago

#92 closed bug (fixed)

option("redSB") in quotient rings produces unexepected results and Segment fault

Reported by: laplagne Owned by: hannes
Priority: major Milestone: Release 3-1-0
Component: singular-kernel Version:
Keywords: option redSB quotient ring Cc:


Over quotient rings, if the option("redSB") is set, the groebner bases are sometimes not reduced. They can even contain repeated polynomials.

This causes Segment Faults when using other procedures.

Here is the example.


A Computer Algebra System for Polynomial Computations / version 3-1-0


by: G.-M. Greuel, G. Pfister, H. Schoenemann \ Aug 2008

FB Mathematik der Universitaet, D-67653 Kaiserslautern \ executing /users/urmel/alggeom/hannes/murrumesh/LIB/.singularrc

ring r = 0, (x, y), ds; ideal I = x2-y3; qring q = groebner(I); ideal U1 = x2, xy2; ideal U2 = xy2, y3; groebner(U2);

_[1]=xy2 _[2]=y3

option("redSB"); groebner(U2);

_[1]=y3 _[2]=xy2 _[3]=y3


_[1]=y3 _[2]=xy2 _[3]=y3

reduce(U1, groebner(U2));

Singular : signal 11 (v: 3100/2009021209): Segment fault/Bus error occurred at 2ac2a7af02d0 because of 10297 (r:1235731989) please inform the authors trying to restart...

(I used here a local ordering, but similar things happen under global orderings.)

Attachments (1)

redSBSignal.txt (194 bytes) - added by laplagne 15 years ago.
Singular script that produces the Segment Fault

Download all attachments as: .zip

Change History (3)

Changed 15 years ago by laplagne

Attachment: redSBSignal.txt added

Singular script that produces the Segment Fault

comment:1 Changed 15 years ago by hannes

Resolution: fixed
Status: newclosed

both bugs fixed.

comment:2 Changed 15 years ago by seelisch

Milestone: Release 3-1-0
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