[George]'s son [John] is in the hospital. [John]'s brother [Douglas] accidentally hit him with a hammer.
('George', 'Douglas')
[George]'s son [John] is in the hospital. [John]'s brother [Douglas] accidentally hit him with a hammer.
[{('George', 'son', 'Douglas'): [('George', 'son', 'John'), ('John', 'brother', 'Douglas')]}]
['son', 'brother']