user_query: Help me add bacon to my Walmart list
response_text: Alright, I added bacon.
user_query: Sorry can you add eggs instead?
response_text: OK. Eggs on your list called "walmart". Anything else?
User: Get me a lyft a 5pm to the dentist.
Parse: Order_ride ( dropoff_location « dentist » pickup_time « 5pm » provider « lyft » )