user_query: on the Christmas list, add ice cream
response_text: Got it, I added ice cream.
user_query: take it back off
response_text: Which list?
User: I would like to cancel MyTaxi, I mean Lyft that was supposed to be at Walmart at 6pm today.
Parse: Cancel_ride ( pickup_location « Walmart » pickup_time « 6pm today » provider « Lyft » )