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7.5.5.0. inForm
Procedure from library dmodapp.lib (see dmodapp_lib).
- Usage:
- inForm(I,w); I ideal or poly, w intvec
- Return:
- ideal, generated by initial forms of generators of I w.r.t. w, or
poly, initial form of input poly w.r.t. w
- Purpose:
- computes the initial form of an ideal or a poly w.r.t. the weight w
- Note:
- The size of the weight vector must be equal to the number of variables
of the basering.
Example:
| | LIB "dmodapp.lib";
ring r = 0,(x,y,Dx,Dy),dp;
def D = Weyl(); setring D;
poly F = 3*x^2*Dy+2*y*Dx;
poly G = 2*x*Dx+3*y*Dy+6;
ideal I = F,G;
intvec w1 = -1,-1,1,1;
intvec w2 = -1,-2,1,2;
intvec w3 = -2,-3,2,3;
inForm(I,w1);
==> _[1]=2*y*Dx
==> _[2]=2*x*Dx+3*y*Dy+6
inForm(I,w2);
==> _[1]=3*x^2*Dy
==> _[2]=2*x*Dx+3*y*Dy+6
inForm(I,w3);
==> _[1]=3*x^2*Dy+2*y*Dx
==> _[2]=2*x*Dx+3*y*Dy+6
inForm(F,w1);
==> 2*y*Dx
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