Classify
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Deformations
Equidim Part
Existence
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Flatness
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Hilbert Series
Membership
Monodromy
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Primdec
Puiseux
Plane Curves
Solving
Space Curves
Spectrum
Primary Decomposition
Task: Decompose the variety defined by
I=(y2z2-x2y3-xz3+x3yz , y2z-xz2)
into its irreducible components via primary decomposition.
LIB "primdec.lib";
ring r=0,(x,y,z),dp;
ideal i=y^2*z^2-x^2*y^3-x*z^3+x^3*y*z,y^2*z-x*z^2;
primdecGTZ(i);
[1]:
[1]: _[1]=-y2+xz
[2]: _[1]=-y2+xz
[2]:
[1]: _[1]=z2
_[2]=y
[2]: _[1]=z
_[2]=y
[3]:
[1]: _[1]=z
_[2]=x2
[2]: _[1]=z
_[2]=x

The result we got is a list of 3 tuples of ideals, where the first ideals are the primary and the second ideals are the corresponding prime ideals. Hence,


Lille, 08-07-02 http://www.singular.uni-kl.de