user_query: add Top Gun to old movies list
response_text: I couldn't find a list called "Old Movies." Do you want me to make one?
user_query: yes
response_text: OK, I made a list called "Old Movies" and added Top Gun.
User: add Top Gun to movies list instead
Parse: Add_item_to_list ( items « Top Gun » list_label « movies » list_singular_or_plural « list » )