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GB.GetNthSyzShifts

shifts of the Nth syzygy module computed so far

Syntax
$gb.GetNthSyzShifts(M:IDEAL or MODULE, N:INT):TAGGED("shifts")

Description
***** NOT YET IMPLEMENTED *****

This function, if used after executing Res(M) , returns the shifts for the Nth syzygy module for M. Within the Interactive Groebner Framework, in which resolutions may be computed one step at a time, the function returns shifts of the part of the Nth syzygy module computed so far.

Example
  Use R ::= QQ[t,x,y,z];
  I := Ideal(x^2-yt, xy-zt, xy);
  $gb.Start_Res(I);
  $gb.Steps(I,6);
  $gb.GetNthSyzShifts(I,2);
Shifts([x^2yz])
-------------------------------
  $gb.Complete(I);
  $gb.GetNthSyzShifts(I,2);
Shifts([x^2yz, txyz, tx^2z, x^3y])
-------------------------------
  J := Ideal(t,x)^3;
  Res(J);
0 --> R^3(-4) --> R^4(-3)
-------------------------------
  $gb.GetNthSyzShifts(J,1);
Shifts([x^3, tx^2, t^2x, t^3])
-------------------------------
  $gb.GetNthSyzShifts(J,2);
Shifts([tx^3, t^2x^2, t^3x])
-------------------------------
  SS := It;
  SS[1];
tx^3
-------------------------------

See Also