D.5.1.12 A_L

Procedure from library classify.lib (see classify_lib).

Usage:

A_L(f); f poly
A_L(s); s string, the name of the singularity

Compute:

the normal form of f in Arnold’s list of singularities in case 1, in case 2 nothing has to be computed.

Return:

A_L(f): compute via ’milnorcode’ the class of f and return the normal form of f found in the database.
A_L("name"): get the normal form from the database for the singularity given by its name.

Example:

LIB "classify.lib";
ring r=0,(a,b,c),ds;
poly f=A_L("E[13]");
f;
→ c2+a3+ab5+b8
A_L(f);
→ Singularity R-equivalent to :  E[6k+1]=E[13]
→ normal form : c2+a3+ab5+b8
→ c2+a3+ab5+b8