[Dale] called his brother, [Nicholas], to confirm when [Nicholas]'s sister, [Nancy], was coming to the dinner.
('Nancy', 'Dale')
[Dale] called his brother, [Nicholas], to confirm when [Nicholas]'s sister, [Nancy], was coming to the dinner.
[{('Nancy', 'brother', 'Dale'): [('Nancy', 'brother', 'Nicholas'), ('Nicholas', 'brother', 'Dale')]}]
['brother', 'brother']