miscellaneous oddities in {\mathbb Z}[x] -- just for bookkeeping

[anne]

Singular-Version:

Singular 3-1-0, pl-23, static

Issue 1: on x86 and x86-64 ======== Sample session showing weird behavior of intersect in {\mathbb Z}[x]:

ring r=integer,x,dp;

You are using coefficients rings which are not fields. Please note that only limited functionality is available for these coefficients. The following commands are meant to work: - basic polynomial arithmetic - std - reduce

intersect(ideal(2),ideal(3));

_[1]=3

intersect(ideal(3),ideal(2));

_[1]=2

Issue 2: on x86-64 ======== Same task as issue 1, but direct approach. Direct computation of intersection works fine on the first few tries, but crashes after that:

ideal I=3x,2-2x; eliminate(I,x);

_[1]=-6

eliminate(I,x);

_[1]=-6

eliminate(I,x);

Singular : signal 11 (v: 3100/2008100214): Segment fault/Bus error occurred at 900000014 because of 10206 (r:1237395016) please inform the authors trying to restart...

Issue 3: on x86 and x86-64 ======== 'charstr' and 'char' are used in different places to create new rings. The following behavior causes crashes (for charstr) or passing to ground field {\mathbb Q} (for char):

ring r=integer,x,dp; charstr(r);

coefficient ring

char(r);

0

Issue 4: on x86 and x86-64 ======== Error message when using reduce:

ring r=integer,x,(c,dp); module bla=....; input suppressed, bla was output of a longer computation bla;

bla[1]=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,-1] bla[2]=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,x] bla[3]=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,-2] bla[4]=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,x] bla[5]=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,-2,0,-1] bla[6]=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,x] bla[7]=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,-1,0,-1,0,-1] bla[8]=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,-1,0,-1,0,-1] bla[9]=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,1] bla[10]=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,-1] bla[11]=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,-1,0,0,0,0,-1] bla[12]=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,-2] bla[13]=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,x] bla[14]=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,-1,0,-1,0,0,0,0,0,0,1] bla[15]=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,-1,0,-1,0,-1] bla[16]=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,1] bla[17]=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,1] bla[18]=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,-1] bla[19]=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,-1] bla[20]=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1] bla[21]=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1] bla[22]=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1] bla[23]=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,1] bla[24]=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,1] bla[25]=[0,0,0,0,0,0,0,0,0,0,0,0,0,0,-1] bla[26]=[0,0,0,0,0,0,0,0,0,0,0,0,0,1] bla[27]=[0,0,0,0,0,0,0,0,0,0,0,0,1] bla[28]=[0,0,0,0,0,0,0,0,0,0,0,-1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,-1,0,-1] bla[29]=[0,0,0,0,0,0,0,0,0,0,-1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,-1,0,-1] bla[30]=[0,0,0,0,0,0,0,0,0,1] bla[31]=[0,0,0,0,0,0,0,0,1] bla[32]=[0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,-1] bla[33]=[0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,-1] bla[34]=[0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,-1,0,-1] bla[35]=[0,0,0,0,-1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,-1,0,-1] bla[36]=[0,0,0,1] bla[37]=[0,0,1] bla[38]=[0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1] bla[39]=[1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,-1]

reduce(freemodule(36),std(bla));

? pNorm not possible in the case of coefficient rings. ? pNorm not possible in the case of coefficient rings. ? pNorm not possible in the case of coefficient rings. ? pNorm not possible in the case of coefficient rings. ? error occurred in STDIN line 266: reduce(freemodule(36),bla);

[seelisch]

here's the input from old ticket #191: Thomas Cluzeau hat den folgenden Bug gefunden. Beim Ausführen von: option(noredefine);option(redSB);LIB "matrix.lib";LIB "ring.lib";LIB "involut.lib";LIB "poly.lib"; ring r = (integer,10),(x,y,z),dp; setring r; option(redTail);short=0; matrix m[2][3] = 0,y,2*x,x,x,x; syz(m); transpose(syz(m)); ensteht ein Segmentation fault: Singular : signal 11 (v: 3100/2009041417): current line:>>transpose(syz(m));<< Segment fault/Bus error occurred at 7feb143445d0 because of 10202 (r:1258661297) please inform the authors trying to restart...

[seelisch]

everything works in 3-1-1 (except issue 4 bug which is somewhat unclear); everything else probably fixed by Oliver?

Anne, please post issue 4 again more precisely as new ticekt.