user_turns: <SILENCE> cantonese food cantonese food north_american food north_american type food any area no south of town yes right east of town west of town right thank you good bye
system_turns: Hello , welcome to the Cambridge restaurant system . You can ask for restaurants by area , price range or food type . How may I help you ? You are looking for a vietnamese restaurant right? I'm sorry but there is no restaurant serving cantonese food Did you say you are looking for a restaurant in the north of town? I'm sorry but there is no north_american restaurant in the north of town Did you say you are looking for a restaurant in the north of town? I'm sorry but there is no north_american restaurant in the north of town You are looking for a north_american restaurant right? I'm sorry but there is no north_american restaurant in the south of town I'm sorry but there is no north_american restaurant in the east of town You are looking for a north_american restaurant right? I'm sorry but there is no north_american restaurant in the west of town  you are welcome