Task: Text to Code
Input (English): SQL: SELECT T1.LastName FROM Customer AS T1 WHERE T1.CustomerId NOT IN ( SELECT T2.CustomerId FROM Invoice AS T2 WHERE T2.Total < 20 )
Feedback: Replace Customer's customer id with Invoice's customer id and total should be equals or less than 20.
Output (English): SELECT LastName FROM CUSTOMER EXCEPT SELECT T1.LastName FROM CUSTOMER AS T1 JOIN Invoice AS T2 ON T1.CustomerId  =  T2.CustomerId WHERE T2.total  >  20