text: B := FILTER lineitem BY shipdate <= 19980902;
  D := SELECT 
  	returnflag AS l_returnflag, 
  	linestatus AS l_linestatus, 
  	SUM(qty) AS sum_qty, 
  	SUM(price) AS sum_base_price, 
  	SUM((1-discount)*price) AS sum_disc_price, 
  	SUM((1+tax)*(1-discount)*price) AS sum_charge, 
  	AVG(qty) AS avg_qty, 
  	AVG(price) AS avg_price, 
  	AVG(discount) AS avg_disc, 
  	COUNT(qty) AS count_order 
  FROM B GROUP BY returnflag, linestatus;
  RES := ORDER D BY l_returnflag ASC, l_linestatus ASC;
  