reduce fails for example ; std(J)<> std( std(J) )

[jakobkroeker]

option(redSB);
LIB "primdec.lib";
ring rng = (integer),(x,y,z),dp;
ideal I = -25*x^3+104*x*y^3-23*y^2*z-128;
ideal J = -118*x*y^3*z+50*x*y^2*z^2-50*x*y*z-49*y,149*x*y^2*z^2-142*y^2-112;
ideal gI =  std(I);
ideal gJ =  std(J);
reduce (I,gI );
reduce (J,gJ );

ASSUME(0, 0== size( std(reduce (I,gI ) ))  );
ASSUME(0, 0== size( std(reduce (J,gJ ) ))  );

check in M2 says that J == gJ:

R = ZZ[x,y,z]

gJ = ideal(16756*y^4-7100*y^3*z+7301*y^2*z+20316*y^2-5600*y*z+5600,4172000*x*z^2+9383360*y^3*z-3976000*y^2*z^2+9383360*y^2+4088560*y*z^2+7400960*y*z-3136000*z^2+4088560*z+7400960,7450*x*y*z^2+16756*y^3-7100*y^2*z+7301*y*z+13216*y-5600*z,13216*x*y^2*z-5600*x*y*z^2+5600*x*z+5488,x*y^2*z^2-537600*x*y*z^3+537600*x*z^2+1209130*y^2+526848*z+953680,118*x*y^3*z-26880000*x*y*z^3+50*x*y*z+26880000*x*z^2+60456500*y^2+49*y+26342400*z+47684000)

J = ideal(-118*x*y^3*z+50*x*y^2*z^2-50*x*y*z-49*y,149*x*y^2*z^2-142*y^2-112)

J == gJ -- true !

also weird is that std(J) differs from std(std(J)) (look at the second generator):

> gJ;
gJ[1]=7450*x*y*z^2+16756*y^3-7100*y^2*z+7301*y*z+13216*y-5600*z
gJ[2]=4172000*x^2*z^2+4088560*x*y*z^2+9383360*x*y^2+3424960*x*y*z-3136000*x*z^2+4088560*x*z+7400960*x-3896480*y
gJ[3]=9383360*y^3*z-3976000*y^2*z^2+4172000*x*z^2+4088560*y*z^2+9383360*y^2+7400960*y*z-3136000*z^2+4088560*z+7400960
gJ[4]=13216*x*y^2*z-5600*x*y*z^2+5600*x*z+5488
gJ[5]=16756*y^4-404235155900*y^3*z+171286080000*y^2*z^2+7301*y^2*z-179729760000*x*z^2-176135164800*y*z^2-404235128484*y^2-318833362400*y*z+135098880000*z^2-176135164800*z-318833351200
gJ[6]=x*y^2*z^2-537600*x*y*z^3+537600*x*z^2+1209130*y^2+526848*z+953680
gJ[7]=118*x*y^3*z-26880000*x*y*z^3+50*x*y*z+26880000*x*z^2+60456500*y^2+49*y+26342400*z+47684000
> std(gJ);
_[1]=7450*x*y*z^2+16756*y^3-7100*y^2*z+7301*y*z+13216*y-5600*z
_[2]=834400*x^2*z^2+817712*x*y*z^2+1876672*x*y^2+684992*x*y*z-627200*x*z^2+817712*x*z+1480192*x-779296*y
_[3]=1876672*y^3*z-795200*y^2*z^2+834400*x*z^2+817712*y*z^2+1876672*y^2+1480192*y*z-627200*z^2+817712*z+1480192
_[4]=13216*x*y^2*z-5600*x*y*z^2+5600*x*z+5488
_[5]=16756*y^4-404235155900*y^3*z+171286080000*y^2*z^2+7301*y^2*z-179729760000*x*z^2-176135164800*y*z^2-404235128484*y^2-318833362400*y*z+135098880000*z^2-176135164800*z-318833351200
_[6]=x*y^2*z^2-537600*x*y*z^3+537600*x*z^2+1209130*y^2+526848*z+953680
_[7]=118*x*y^3*z-26880000*x*y*z^3+50*x*y*z+26880000*x*z^2+60456500*y^2+49*y+26342400*z+47684000

another failing example:

option(redSB);
LIB "primdec.lib";
LIB "wrappers.lib";
ring rng = (integer),(x,y,z),(dp(3),C);
int trial = 0;
system("random", 912758297);
ideal I = -27*x+25*z,-46*x*z+35*x,21*x-42;
       ideal gI =  std(I);
       ideal ggI =  std(gI);
       ideal sI =  sba(I);

reduce (I,gI );

ASSUME(0, 0== size( std(reduce (I,gI ) ))  );

[jakobkroeker]

simplified failing example:

LIB "primdec.lib";
ring rng = (integer),(x,y,z),dp;
short = 0 ;
option(redSB);
option(redTail);
ideal J = -17*x*y^3*z+x*y^2*z+5*x*y*z, 5*x*y^2*z+14;
ideal gJ =  std(J);
reduce (J,gJ );
reduce (J,std(gJ) );
gJ;

string(J);

in M2:

R = ZZ[x,y,z]

J = ideal(-17*x*y^3*z+x*y^2*z+5*x*y*z,5*x*y^2*z+14)
gJ = ideal groebnerBasis J

[adipopescu]

Disableling the chainCrit removes the problem also in this case

[jakobkroeker]

Disablling the chainCrit removes the problem also in this case

is it possible to disable criteria (e.g. 'chainCrit') and control the std strategies by Singular interpreter?

It would probably shorten the debug loop (edit src, compile, test, debug) for some cases. Maybe you could discuss this with Hans?

[adipopescu]

Solved