Task: Text to Code
Input (English): Show names for all employees who do not have certificate of Boeing 737-800.
Output (English): SELECT name FROM Employee EXCEPT SELECT T1.name FROM Employee AS T1 JOIN Certificate AS T2 ON T1.eid  =  T2.eid JOIN Aircraft AS T3 ON T3.aid  =  T2.aid WHERE T3.name  =  "Boeing 737-800"