generate response: The train must arrive by 11:15 and I do not care what time time it leaves. Please book one for 4 people and give me the reference number.. Intent: book_train. Slots: train-arriveby=11:15, train-bookpeople=4, train-day=tuesday, train-departure=cambridge, train-destination=london liverpool street
Response: The TR4259 fits your needs. Would you like me to book this one? You will get there at 09:27, but the next one doesn't arrive until 01:27.