[Clarence] made a sandwich for his son [Dale]. [Dale]'s brother [Wayne] ate an apple instead.
('Clarence', 'Wayne')
[Clarence] made a sandwich for his son [Dale]. [Dale]'s brother [Wayne] ate an apple instead.
[{('Clarence', 'son', 'Wayne'): [('Clarence', 'son', 'Dale'), ('Dale', 'brother', 'Wayne')]}]
['son', 'brother']