801     protected function eq($left, $right)  argument
803         return $left == $right;
1454         [, $op, $left, $right, $whiteBefore, $whiteAfter] = $exp;
1457         $right = $this->reduce($right, true);
1463         if ($rightColor = Color::coerceColor($right)) {
1464             $right = $rightColor;
1468         $rtype = $right[0];
1472             return Util::toBool($left == Constants::TRUE && $right == Constants::TRUE);
1476             return Util::toBool($this->eq($left, $right));
1479         if ($op == '+' && !is_null($str = $this->stringConcatenate($left, $right))) {
1486             $out = $this->$fname($op, $left, $right);
1495         return ['string', '', [$left, $paddedOp, $right]];
1498     protected function stringConcatenate($left, $right)  argument
1501             if ($right[0] == 'string') {
1502                 $right[1] = '';
1504             $strLeft[2][] = $right;
1508         if ($strRight = $this->coerceString($right)) {
1542     protected function op_color_color($op, $left, $right)  argument
1545         $max = count($left) > count($right) ? count($left) : count($right);
1548             $rval = $right[$i] ?? 0;
1578     protected function op_number_number($op, $left, $right)  argument
1580         $unit = empty($left[2]) ? $right[2] : $left[2];
1585                 $value = $left[1] + $right[1];
1588                 $value = $left[1] * $right[1];
1591                 $value = $left[1] - $right[1];
1594                 $value = $left[1] % $right[1];
1597                 if ($right[1] == 0) throw new Exception('parse error: divide by zero');
1598                 $value = $left[1] / $right[1];
1601                 return Util::toBool($left[1] < $right[1]);
1603                 return Util::toBool($left[1] > $right[1]);
1605                 return Util::toBool($left[1] >= $right[1]);
1607                 return Util::toBool($left[1] <= $right[1]);