inform((_:search,area,'dontcare');(_:search,food,'persian');(_:search,type,'Restaurant'))
user
I want to find a restaurant in any area and servings persian food .
request((_:search,food,?);(_:search,type,'Restaurant')) canthelp((_:search,type,'Restaurant')) inform((_:result,food,'Persian');(_:result,type,'Restaurant'))
system
Sorry , there are no restaurants serving Persian food available .   May I help you find a different sort of food ?
inform((_:search,food,'vietnamese');(_:search,type,'Restaurant')) request((_:result,address,?);(_:result,phone,?);(_:result,type,'Restaurant'))
user
vietnamese , please . Give me their address and phone number as well .
system
Yes , the restaurant name is Thanh Binh , the phone number is 01223 362456 . The address is 17 Magdalene Street City Centre
_:search area dontcare
_:search food persian
_:search type Restaurant
_:search area dontcare
_:system canthelp _:search/6b7ae4b4
_:search/6b7ae4b4 type Restaurant
_:result food Persian
_:result type Restaurant
_:search food vietnamese
_:search type Restaurant
_:result address ?
_:result phone ?