D.6.3.6 InvariantQ

Procedure from library rinvar.lib (see rinvar_lib).

Usage:

InvariantQ(f, G, action); poly f; ideal G, action

Purpose:

check if the polynomial f is invariant w.r.t. G where G acts via ’action’ on K^m.

Assume:

basering = K[s_1,...,s_m,t_1,...,t_m] where K = Q of K = Q(a) and minpoly != 0, f contains only t_1,...,t_m, G is the ideal of an algebraic group and a standard basis.

Return:

int;
0 if f is not invariant,
1 if f is invariant

Note:

G need not be finite