user_query: check playoff tree on sports list
response_text: Which list?
user_query: check it off
response_text: Which list?
user_query: sports
response_text: OK, I added playoff tree.
user_query: add playoff tree to my list
response_text: OK. Which list do you want to add to?
User: End walking on Fitbit, no, my phone.
Parse: Stop_exercise ( activity « walking » device « phone » )