D.5.5.13 is_irred

Procedure from library hnoether.lib (see hnoether_lib).

Usage:

is_irred(f); f poly

Assume:

f is a squarefree bivariate polynomial (in the first 2 ring variables).

Return:

int (0 or 1):
- is_irred(f)=1 if f is irreducible as a formal power series over the algebraic closure of its coefficient field (f defines an analytically irreducible curve at zero),
- is_irred(f)=0 otherwise.

Note:

0 and units in the ring of formal power series are considered to be not irreducible.

Example:

LIB "hnoether.lib";
ring exring=0,(x,y),ls;
is_irred(x2+y3);
→ 1
is_irred(x2+y2);
→ 0
is_irred(x2+y3+1);
→ 0