generate response: I'll be departing Bishops Stortford. My departure time is flexible, but I need to arrive by 16:30.. Intent: find_train. Slots: train-arriveby=16:30, train-day=tuesday, train-departure=bishops stortford, train-destination=cambridge
Response: The Bishops Stortford to Cambridge at 15:29 is scheduled to arrive at 16:07. The one before that is two hours earlier.