user_query: Erase some items from my to-do list.
response_text: Which item?
user_query: any item
response_text: Which item?
user_query: Add wash dishes to my to-do list.
response_text: Which item?
user_query: Add wash dishes to the list called to-do.
response_text: I couldn't find those two things on your list called "To Do."
user_query: Add wash dishes to my to-do list.
response_text: Which item?
User: I no longer need a Taxi trip at noon.
Parse: Cancel_ride ( pickup_time « noon » )