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Comb. Appl.
HCA Proving
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Equidim Part
Existence
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Flatness
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Nonnormal Locus
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Primdec
Puiseux
Plane Curves
Saturation
Solving
Space Curves
Spectrum
SINGULAR Example: Flattening Stratification
We compute the flattening stratification of M, given by the presentation

LIB "matrix.lib";
ring A=0,(x(0..4)),dp;
matrix M[2][4] = x(0),x(1),x(2),x(3),x(1),x(2),x(3),x(4);
flatteningStrat(M);

==>
  [1]:
     _[1]=x(3)^2-x(2)*x(4)
     _[2]=x(2)*x(3)-x(1)*x(4)
     _[3]=x(1)*x(3)-x(0)*x(4)
     _[4]=x(2)^2-x(0)*x(4)
     _[5]=x(1)*x(2)-x(0)*x(3)
     _[6]=x(1)^2-x(0)*x(2)
  [2]:
     _[1]=x(4)
     _[2]=x(3)
     _[3]=x(2)
     _[4]=x(1)
     _[5]=x(0)
    
From the output we can read the flattening stratification of M:





where

Application to Singularities.

Sao Carlos, 08/02 http://www.singular.uni-kl.de