def lbp_sub(f, g):
 if (sig_cmp(Sign(f), Sign(g), Polyn(f).ring.order) < 0):
  max_poly = g
 else:
  max_poly = f
 ret = (Polyn(f) - Polyn(g))
 return lbp(Sign(max_poly), ret, Num(max_poly))

def lbp_sub ( f , g ) : if ( sig_cmp ( Sign ( f ) , Sign ( g ) , Polyn ( f ) . ring . order ) < 0 ) : max_poly = g else : max_poly = f ret = ( Polyn ( f ) - Polyn ( g ) ) return lbp ( Sign ( max_poly ) , ret , Num ( max_poly ) )
subtract labeled polynomial g from f .