generate response: And this train leaves from Cambridge? If so could you please book it for 7 people and give me the reference number?. Intent: book_train. Slots: train-arriveby=16:07, train-bookpeople=7, train-day=tuesday, train-departure=cambridge, train-destination=bishops stortford, train-leaveat=15:29
Response: Yes, it leaves from Cambridge. I have booked this for you, and your reference number is GIXX2M35 .