[George] made a grilled cheese for his son [John]. [John]'s brother [Jerry] ate a salad.
('George', 'Jerry')
[George] made a grilled cheese for his son [John]. [John]'s brother [Jerry] ate a salad.
[{('George', 'son', 'Jerry'): [('George', 'son', 'John'), ('John', 'brother', 'Jerry')]}]
['son', 'brother']