D.5.5.16 is_NND

Procedure from library hnoether.lib (see hnoether_lib).

Usage:

is_NND(f[,mu,NP]); f poly, mu int, NP list of intvecs

Assume:

f is convenient, that is, f(x,0) != 0 != f(0,y);
mu (optional) is Milnor number of f.
NP (optional) is output of newtonpoly(f).

Return:

int: 1 if f in Newton non-degenerate, 0 otherwise.

Example:

LIB "hnoether.lib";
ring r=0,(x,y),ls;
poly f=x5+y3;
is_NND(f);
→ 1
poly g=(x-y)^5+3xy5+y6-y7;
is_NND(g);
→ 0
// if already computed, one should give the Minor number and Newton polygon
// as second and third input: 
int mu=milnor(g);
list NP=newtonpoly(g);
is_NND(g,mu,NP);
→ 0

See also: newtonpoly.