user_query: Can you make a list and add paper plates, napkins, tablecloth, plasticware, and foil
response_text: OK, what do you want to call it?
user_query: Picnic
response_text: Alright, I made a list called "Picnic" and added those four things.
User: Start a bike ride for 30 minutes, no, an hour.
Parse: Start_exercise ( activity « bike » duration « an hour » )