D.5.1.9 quickclass

Procedure from library classify.lib (see classify_lib).

Usage:

quickclass(f); f=poly

Return:

Normal form of f in Arnold’s list

Remark:

try to determine the normal form of f by invariants, mainly by computing the Hilbert function of the Milnor algebra, no coordinate change is needed (see also proc ’milnorcode’).

Example:

LIB "classify.lib";
ring r=0,(x,y,z),ds;
poly f=(x2+3y-2z)^2+xyz-(x-y3+x2*z3)^3;
quickclass(f);
→ Singularity R-equivalent to :  D[k]=D[4]
→ normal form : z2+x2y+y3
→ z2+x2y+y3