Opened 15 years ago

Closed 15 years ago

# reported by Stas: bug in factorize and elim

Reported by: Owned by: seelisch hannes major Release 3-1-0 factory factorize, elim

### Description

Liebes Team,

Bei mir die folgende Probleme aufgetreten sind (3-1-0, Aug 2008).

1.) factorize

ring r=(2,a),(x,y,z),lp;minpoly=a2+a+1; poly f=(x+z)*(x+y+z); product of two linear functions factorize(f); false!

[1]:

_[1]=1 _[2]=x2+xy+yz+z2

[2]:

1,1

poly f=(x+z)*(x+y); factorize(f); this one is OK

[1]:

_[1]=1 _[2]=x+z _[3]=x+y

[2]:

1,1,1

this problem does not occur in char=0 ring r=0,(x,y,z),lp; poly f=(x+z)*(x+y+z); factorize(f);

[1]:

_[1]=1 _[2]=x+z _[3]=x+y+z

[2]:

1,1,1

2.) elim

Im Help steht es niergenwo, dass id in elim(id,v) soll ein GB (SB) sein. Bei mir aber habe ich gemerkt, dass bei id und std(id) man verschiedene Outputs kriegt.

ring r=(16,a),(V(2..1),U(15..1)),lp; ideal sys=a12*U(13)+a9*U(10)+a8*U(9)+a6*U(7)+a4*U(5)+a3*U(4)+a2*U(3)+a*U(2), U(13)+U(10)+U(9)+U(7)+U(5)+U(4)+U(3)+U(2), a3*U(13)+a6*U(10)+a7*U(9)+a9*U(7)+a11*U(5)+a12*U(4)+a13*U(3)+a14*U(2), a6*U(13)+a12*U(10)+a14*U(9)+a3*U(7)+a7*U(5)+a9*U(4)+a11*U(3)+a13*U(2), a9*U(13)+a3*U(10)+a6*U(9)+a12*U(7)+a3*U(5)+a6*U(4)+a9*U(3)+a12*U(2), a12*U(13)+a9*U(10)+a13*U(9)+a6*U(7)+a14*U(5)+a3*U(4)+a7*U(3)+a11*U(2), U(13)+U(10)+a5*U(9)+U(7)+a10*U(5)+U(4)+a5*U(3)+a10*U(2), a3*U(13)+a6*U(10)+a12*U(9)+a9*U(7)+a6*U(5)+a12*U(4)+a3*U(3)+a9*U(2), V(1)*U(1)+U(2), V(1)*U(2)+U(3), V(1)*U(3)+U(4), V(1)*U(4)+U(5), V(1)*U(5)+U(6), V(1)*U(6)+U(7), V(1)*U(7)+U(8), V(1)*U(8)+U(9), V(1)*U(9)+U(10), V(1)*U(10)+U(11), V(1)*U(11)+U(12), V(1)*U(12)+U(13), V(1)*U(13)+U(14), V(1)*U(14)+U(15), V(1)*U(15)+U(1); elim(sys,1..2); eliminate V(1) and V(2), is not correct!

_[1]=U(1)

elim(std(sys),1..2); now is OK

_[1]=U(1) _[2]=U(2) _[3]=U(3) _[4]=U(4) _[5]=U(5) _[6]=U(6) _[7]=U(7) _[8]=U(8) _[9]=U(9) _[10]=U(10) _[11]=U(11) _[12]=U(12) _[13]=U(13) _[14]=U(14) _[15]=U(15)

Grüße, Stas.

### comment:1 Changed 15 years ago by bulygin

Resolution: → duplicate new → closed

### comment:2 Changed 15 years ago by seelisch

Milestone: → Release 3-1-0
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