Could you please find all the procedure that Jon Wen was trained in?
SELECT * 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"
Jon Wen being trained in procedures involves joining tables: physician, trained_in, and procedures; finding all procedures refers to SELECT * FROM procedures; Jon Wen's name is a filter condition for the physician table;