[Theresa] sat anxiously in the airport terminal, waiting to see her son [Nicolas] walk through the gate. [Tony] went to the grocery store for his brother [Nicolas], because he broke his leg.
('Theresa', 'Tony')
[Theresa] sat anxiously in the airport terminal, waiting to see her son [Nicolas] walk through the gate. [Tony] went to the grocery store for his brother [Nicolas], because he broke his leg.
[{('Theresa', 'son', 'Tony'): [('Theresa', 'son', 'Nicolas'), ('Nicolas', 'brother', 'Tony')]}]
['son', 'brother']