code: private static final boolean is_overflow(long10 x) {
  		return (
  			((x._0 > P26-19)) &&
  			((x._1 & x._3 & x._5 & x._7 & x._9) == P25) &&
  			((x._2 & x._4 & x._6 & x._8) == P26)
  			) || (x._9 > P25);
  	}
docs: /* Check if reduced-form input >= 2^255-19