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D.4.28.19 zerodec
Procedure from library primdec.lib (see primdec_lib).
- Usage:
- zerodec(I); I ideal
- Assume:
- I is zero-dimensional, the characteristic of the ground field is 0
- Return:
- list of primary ideals, the zero-dimensional decomposition of I
- Note:
- The algorithm (of Monico), works well only for a small total number
of solutions (
vdim(std(I)) should be < 100) and without
parameters. In practice, it works also in large characteristic p>0
but may fail for small p.
If printlevel > 0 (default = 0) additional information is displayed.
Example:
| LIB "primdec.lib";
ring r = 0,(x,y),dp;
ideal i = x2-2,y2-2;
list pr = zerodec(i);
pr;
==> [1]:
==> _[1]=y2-2
==> _[2]=xy-2
==> _[3]=x2-2
==> [2]:
==> _[1]=y2-2
==> _[2]=xy+2
==> _[3]=x2-2
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