[Milton] and his sister [Emily] went to the ice skating rink. [Milton] fell down and [Emily] laughed at him. [Emily] and her father [Nicholas] went to the park. They had a wonderful time there, feeding the ducks.
('Milton', 'Nicholas')
[Milton] and his sister [Emily] went to the ice skating rink. [Milton] fell down and [Emily] laughed at him. [Emily] and her father [Nicholas] went to the park. They had a wonderful time there, feeding the ducks.
[{('Milton', 'father', 'Nicholas'): [('Milton', 'sister', 'Emily'), ('Emily', 'father', 'Nicholas')]}]
['sister', 'father']