hnoether.lib
squarefree(f)
LIB "hnoether.lib"; ring exring=7,(x,y),dp; poly f=(x+y)^7*(x-y)^8; poly g=squarefree(f); g; // factor x+y lost, since characteristic=7 ==> x-y allsquarefree(f,g); // all factors (x+y)*(x-y) found ==> x2-y2