Opened 4 years ago

#850 new bug

ffsolve need huge resources and return wrong result

Reported by: anonymous Owned by: somebody
Priority: critical Milestone: 4-2-0 and higher
Component: singular-libs Version: 4-1-2
Keywords: Cc:

Description

I used the following input for Singular (4.1.0 and 4.1.2):

LIB "ffsolve.lib"; ring R = 2,( x13, x6, x21, x14, x28, x26, x34, x20, x29, x22, x36, x42, x61, x66, x74, x68, x73, x79, x100, x96 ),rp; ideal I = x13, -x6, x21, -x14, -x6*x34+x14*x26-x28, x13*x28-x20*x21-x26+x34, -x6, x13, x13-x20+x29, -x6-x22+x26, -x6*x42+x22*x26-x36, x6*x34-x14*x26-x14*x42+x22*x34+x28+x61, x13*x36-x20*x29+x42, -x13*x28+x20*x21+x21*x36-x28*x29+x26-x34+x42-x66, -x6*x21*x36+x6*x28*x29+x13*x14*x36-x13*x22*x28-x14*x20*x29+x20*x21*x22-x6*x42-x6*x79+x14*x42+x14*x73+x22*x26-x22*x34-x22*x66-x68+x74, x13*x74-x21*x36-x21*x68+x28*x29+x29*x61-x42-x79, x13*x74-x20*x74-x21*x36-x21*x68+x28*x29+x28*x68+x29*x61-x36*x61-x42-x79-x100, -x6*x21*x36+x6*x28*x29+x13*x14*x36-x13*x22*x28+x13*x28*x42-x13*x34*x36-x14*x20*x29+x20*x21*x22-x20*x21*x42+x20*x29*x34+x21*x26*x36-x26*x28*x29-x6*x42-x6*x79+x14*x42+x14*x73+x22*x26-x22*x34-x22*x66+x26*x79-x34*x73+x42*x66-x68+x74-x96;

If I then call

ffsolve(I);

or

ffsolve(std(I));

Singular needs 90 to 120 minutes, sometimes uses more than 2GB of memory and in the end returns a list of 32768 solutions. This is wrong, it is easy to work out by hand that there are only 16 solutions. Also

simplesolver(std(I));

returns the correct result.

Another problem: Trying

GBsolve(I);

reveals that there is a typo in ffsolve.lib (varaibles -> variables).

Change History (0)

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