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7.5.11.0. CentralSaturation
Procedure from library ncdecomp.lib (see ncdecomp_lib).
- Usage:
- CentralSaturation(M, T), for a module M and an ideal T
- Assume:
- T is an ideal in the center of the base ring
- Return:
- module
- Purpose:
- compute the central saturation of M by T, that is M:T^{\infty}, by repititive application of
CentralQuot
- Note:
- the output module is not necessarily a Groebner basis
Example:
| | LIB "ncdecomp.lib";
option(returnSB);
def a = makeUsl2();
setring a;
ideal I = e3,f3,h3-4*h;
I = std(I);
poly C=4*e*f+h^2-2*h;
ideal G = C*(C-8);
ideal R = CentralSaturation(I,G);
R=std(R);
vdim(R);
==> 5
R;
==> R[1]=h
==> R[2]=ef-6
==> R[3]=f3
==> R[4]=e3
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See also:
CenCharDec;
CentralQuot.
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