[Nicholas] received a call from his father, [Clarence]. [Clarence] asked where [Nicholas]'s sister, [Nancy], was.
('Nancy', 'Clarence')
[Nicholas] received a call from his father, [Clarence]. [Clarence] asked where [Nicholas]'s sister, [Nancy], was.
[{('Nancy', 'father', 'Clarence'): [('Nancy', 'brother', 'Nicholas'), ('Nicholas', 'father', 'Clarence')]}]
['brother', 'father']