generate response: I need one in the expensive price range that includes free parking.. Intent: find_train. Slots: hotel-area=centre, hotel-parking=yes, hotel-pricerange=expensive, hotel-type=guesthouse, train-day=tuesday, train-departure=cambridge, train-destination=stevenage, train-leaveat=16:15
Response: I'm sorry we don't have an expensive guesthouse in the centre area. Would you like to try some different criteria?