user_query: start a list of potential presents
response_text: Alright, what do you want to call it?
user_query: possible presents
response_text: OK, I made a list called "Possible Presents" and added potential presents.
user_query: Forget the potential presents
response_text: Sure, I deleted potential presents.
User: Get my water bill from last month, actually this month
Parse: Get_bill ( account_type « water » billing_date_span « this month » )