Singular

D.15.8.8 classifyUnimodalMaps

Usage:

classifyUnimodalMaps(I); I an ideal with 2 generators in a polynomial ring with 2 variables and local ordering defining a map germ C^2 to C^2

Compute:

The normal form of the germ in Riegers classification if it is simple

Return:

normal form of I, of type ideal

Note:

If I is not unimodal it returns (0,0)

LIB "classifyMapGerms.lib";
ring R=0,(x,y),(c,ds);
poly f1=x;
poly f2=xy+y6+y9;
poly f11=f1+f2*f1;
poly f22=f2+f1^2;
map phi=basering,x+y,y+y2;
f1=phi(f11);
f2=phi(f22);
ideal I=f1,f2;
classifyUnimodalMaps(I);
==> _[1]=x
==> _[2]=xy+y6+y9