[Douglas] has a brother who is younger than him. The brother has a sister whose name is [Janet]. [George] is taking his son [Douglas] out for coffee.
('George', 'Janet')
[George] is taking his son [Douglas] out for coffee. [Douglas] has a brother who is younger than him. The brother has a sister whose name is [Janet].
[{('George', 'daughter', 'Janet'): [('George', 'son', 'Douglas'), ('Douglas', 'sister', 'Janet')]}]
['son', 'sister']