USER
Hi, I want to order a pizza.
ASSISTANT
Sure, pick up or delivery?
USER
I will pick up.
ASSISTANT
Okay, what would you like to order?
USER
I would like a buffalo chicken pizza please.
buffalo chicken pizza
pizza_ordering.name.pizza
pizza_ordering.name.pizza
ASSISTANT
What size? They have large, medium or personal size.
large
pizza_ordering.size.pizza
pizza_ordering.size.pizza
medium
pizza_ordering.size.pizza
pizza_ordering.size.pizza
personal
pizza_ordering.size.pizza
personal size
pizza_ordering.size.pizza
USER
I would like a large please.
large
pizza_ordering.size.pizza
pizza_ordering.size.pizza
ASSISTANT
Oh, I'm sorry they are out of the buffalo chicken.
buffalo chicken
pizza_ordering.name.pizza.reject
pizza_ordering.name.pizza.reject
USER
That's too bad. Do they have BBQ chicken pizza?
BBQ chicken pizza
pizza_ordering.name.pizza
pizza_ordering.name.pizza
ASSISTANT
Yes, BBQ pizza is available.
BBQ pizza
pizza_ordering.name.pizza
pizza_ordering.name.pizza
USER
Okay, I'll take BBQ pizza instead then.
BBQ pizza
pizza_ordering.name.pizza
pizza_ordering.name.pizza
ASSISTANT
You still want a large?
large
pizza_ordering.size.pizza
pizza_ordering.size.pizza
USER
Yes.
ASSISTANT
Would you like thin crust, traditional or pan pizza.
thin crust
pizza_ordering.type.crust
pizza_ordering.type.crust
traditional
pizza_ordering.type.crust
pizza_ordering.type.crust
pan pizza
pizza_ordering.type.crust
pan pizza.
pizza_ordering.name.pizza
USER
I think traditional is fine.
traditional
pizza_ordering.type.crust
pizza_ordering.type.crust
ASSISTANT
Anything else?
USER
No I think that's all. 
ASSISTANT
Okay, so I have a large BBQ chicken pizza on traditional crust. Is it right?
large
pizza_ordering.size.pizza.accept
pizza_ordering.size.pizza.accept
BBQ chicken pizza
pizza_ordering.name.pizza.accept
pizza_ordering.name.pizza.accept
traditional crust
pizza_ordering.type.crust.accept
pizza_ordering.type.crust.accept
USER
Yes, that's correct.
ASSISTANT
Great, your pizza will be ready for pick up in about 25 minutes.
USER
Perfect. Thank you!
ASSISTANT
You are welcome.