Singular

D.6.11.11 is_irred

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.

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