USER
Hello, can I place an order for a pizza?
ASSISTANT
Sure, what kind of pizza would you like?
USER
Can I get a medium Classic Veggie pizza?
medium
pizza_ordering.size.pizza
Classic Veggie pizza
pizza_ordering.name.pizza
pizza_ordering.name.pizza
ASSISTANT
We are currently out of mushrooms and black olives, would you like something else?
mushrooms
pizza_ordering.type.topping
pizza_ordering.type.topping.reject
black olives
pizza_ordering.type.topping.reject
pizza_ordering.type.topping
USER
Can I get a Buffalo Chicken pizza?
Buffalo Chicken pizza
pizza_ordering.name.pizza
pizza_ordering.name.pizza
ASSISTANT
What size?
USER
A medium.
medium
pizza_ordering.size.pizza
pizza_ordering.size.pizza
ASSISTANT
 Okay would you like anything else?
USER
No thank you, but can you make that a deep dish pizza?
deep dish
pizza_ordering.type.crust
deep dish pizza
pizza_ordering.name.pizza
ASSISTANT
Okay, to confirm you would like a medium deep dish buffalo chicken pizza?
medium
pizza_ordering.size.pizza.accept
pizza_ordering.size.pizza.accept
deep dish
pizza_ordering.type.crust.accept
deep dish buffalo chicken pizza
pizza_ordering.name.pizza.accept
buffalo chicken pizza
pizza_ordering.name.pizza.accept
USER
Yes, do you guys deliver?
ASSISTANT
We do not. 
USER
No problem
ASSISTANT
. Your order is confirmed.
USER
How long will it take?
ASSISTANT
Your pizza should be ready in about 25 minutes. 
USER
Okay and I'll be using my account to pay. 
ASSISTANT
Your receipt will be emailed to you. 
USER
Okay, thank you.
ASSISTANT
See you soon.