Find the names of all procedures such that the cost is less than 5000 and physician John Wen was trained in.
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"