USER
I would like to order a pizza.
ASSISTANT
Ok. Size you would like to order? 
USER
Large
Large
pizza_ordering.size.pizza
pizza_ordering.size.pizza
ASSISTANT
Type of pizza? 
USER
I would like a cheese pizza.
cheese pizza
pizza_ordering.name.pizza
pizza_ordering.name.pizza
ASSISTANT
Any toppings? 
USER
Bacon
Bacon
pizza_ordering.type.topping
pizza_ordering.type.topping
ASSISTANT
Any additional toppings? 
USER
Sliced tomatoes.
Sliced tomatoes
pizza_ordering.type.topping
pizza_ordering.type.topping
ASSISTANT
Sliced tomatoes are not available.
Sliced tomatoes
pizza_ordering.type.topping.reject
pizza_ordering.type.topping.reject
USER
How about sausage instead?
sausage
pizza_ordering.type.topping
pizza_ordering.type.topping
ASSISTANT
OK. 
USER
My order is complete.
ASSISTANT
Pickup or delivery. 
USER
Pickup. 
ASSISTANT
To confirm you ordered a large cheese pizza with bacon and sausage.
large
pizza_ordering.size.pizza.accept
pizza_ordering.size.pizza.accept
cheese pizza
pizza_ordering.name.pizza.accept
pizza_ordering.name.pizza.accept
bacon
pizza_ordering.type.topping.accept
pizza_ordering.type.topping.accept
sausage
pizza_ordering.type.topping.accept
pizza_ordering.type.topping.accept
USER
Yes. 
ASSISTANT
Your total is $12.50. 
USER
Ok. How long until my order is ready?
ASSISTANT
25 minutes. 