[Nicholas] is going to the arcade with his sister, [Nancy]. [Nicholas] went to the park with his father, [Clarence].
('Clarence', 'Nancy')
[Nicholas] went to the park with his father, [Clarence]. [Nicholas] is going to the arcade with his sister, [Nancy].
[{('Clarence', 'daughter', 'Nancy'): [('Clarence', 'son', 'Nicholas'), ('Nicholas', 'sister', 'Nancy')]}]
['son', 'sister']