user_query: put Zombie on the music list
response_text: Alright, here's a YouTube playlist called ALL EE ZOMBIE SONGS - COD - [OFFICIAL] Ksherwoodops, Elena Siegman, Malukah, Clark S Nova.
user_query: add Zombie to the music list
response_text: OK, I added Zombie.
User: How much do I owe on my Visa no my Mastercard bill this month?
Parse: Get_bill ( billing_date_span « this month » card_company « Mastercard » )