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D.5.3.2 isEquising

Procedure from library equising.lib (see equising_lib).

Usage:
isEquising(F[,m]); F poly, m int

Assume:
F defines a deformation of an irreducible bivariate polynomial f and the characteristic of the basering does not divide mult(f).
If nv is the number of variables of the basering, then the first nv-2 variables are the deformation parameters.
If the basering is a qring, ideal(basering) must only depend on the deformation parameters.

Return:
list l of two integers, where
 
   l[1]=1 if F is an equisingular deformation,  l[1]=0 otherwise.
   l[2]=1 if some error has occured,  l[2]=0 otherwise.

Note:
If m is given, the computation stops after m steps of the iteration.
This procedure uses execute or calls a procedure using execute.

Example:
 
LIB "equising.lib";
ring r = 11,(a,b,x,y),ds;
poly F = (x2+2xy+y2+x5)+ay3+bx5;
isEquising(F);
==> [1]:
==>    0
==> [2]:
==>    0
isEquising(F,1);
==> [1]:
==>    1
==> [2]:
==>    0
ideal I = ideal(a);
qring q = std(I);
poly F = imap(r,F);
isEquising(F);
==> [1]:
==>    1
==> [2]:
==>    0

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            User manual for Singular version 2-0-3, February 2002, generated by texi2html.