D.5.7.2 ModEqn
..............
Procedure from library qhmoduli.lib (see qhmoduli_lib).

Usage:
ModEqn(f [, opt]); poly f; int opt;

Purpose:
compute equations of the moduli space of semiquasihomogeneous hypersurface singularity with principal part f w.r.t. right equivalence

Assume:
f quasihomogeneous polynomial with an isolated singularity at 0

Return:
polynomial ring, possibly a simple extension of the ground field of
the basering, containing the ideal 'modid'

- 'modid' is the ideal of the moduli space if opt is even (> 0).
otherwise it contains generators of the coordinate ring R of the
moduli space (note : Spec(R) is the moduli space)

Options:
1 compute equations of the mod. space,

2 use a primary decomposition

4 compute E_f0, i.e., the image of G_f0

To combine options, add their value, default: opt =7

Example:
LIB "qhmoduli.lib";
ring B   = 0,(x,y), ls;
poly f = -x4 + xy5;
def R = ModEqn(f);
setring R;
modid;
==> modid[1]=Y(5)^2-Y(4)*Y(6)
==> modid[2]=Y(4)*Y(5)-Y(3)*Y(6)
==> modid[3]=Y(3)*Y(5)-Y(2)*Y(6)
==> modid[4]=Y(2)*Y(5)-Y(1)*Y(6)
==> modid[5]=Y(4)^2-Y(2)*Y(6)
==> modid[6]=Y(3)*Y(4)-Y(1)*Y(6)
==> modid[7]=Y(2)*Y(4)-Y(1)*Y(5)
==> modid[8]=Y(3)^2-Y(1)*Y(5)
==> modid[9]=Y(2)*Y(3)-Y(1)*Y(4)
==> modid[10]=Y(2)^2-Y(1)*Y(3)

<font size="-1">
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; User manual for <a href="http://www.singular.uni-kl.de/"><i>Singular</i></a> version 2-0-4, October 2002,
generated by <a href="http://www.gnu.org/software/texinfo/"><i>texi2html</i></a>.
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