question: show me all flights from boston to pittsburgh on wednesday of next week which leave boston after 2 o'clock pm 
#1 return flights 
#2 return #1 from  boston 
#3 return #2 to pittsburgh 
#4 return #3 on  wednesday 
#5 return #4 that  are next week 
#6 return #5 which  leave boston after 2 o'clock