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D.8.3.1 parametrize
Procedure from library paramet.lib (see paramet_lib).
- Usage:
- parametrize(I); I ideal in an arbitrary number of variables,
whose radical is prime, in a ring with global ordering
- Create:
- If the parametrization is successful, the basering will be changed to
the parametrization ring, that is to the ring PR=0,(s,t),dp;
respectively PR=0,t(1..d),dp;, depending on the dimension of the
parametrized variety.
- Return:
- a list containing the parametrization ideal resp. the original ideal,
the number of variables needed for the parametrization resp. 0, and
1 resp. 0 depending on whether the parametrization was successful
or not
Example:
| LIB "paramet.lib";
ring RING=0,(x,y,z),dp;
ideal I=z2-y2x2+x3;
parametrize(I);
==> [1]:
==> _[1]=s2-t2
==> _[2]=s
==> _[3]=s2t-t3
==> [2]:
==> 2
==> [3]:
==> 1
| See also:
normal;
parametrizepd;
primdecGTZ;
radical.
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