Question: Find the names of all procedures such that the cost is less than 5000 and physician John Wen was trained in.
SQL: SELECT name FROM procedures WHERE cost  <  5000 INTERSECT SELECT T3.name FROM physician AS T1 JOIN trained_in AS T2 ON T1.employeeid  =  T2.physician JOIN procedures AS T3 ON T3.code  =  T2.treatment WHERE T1.name  =  "John Wen"