[Nicholas] and his daughter [Mary] like to read poems together. [Glen] and his sister [Mary] went to the park.
('Glen', 'Nicholas')
[Glen] and his sister [Mary] went to the park. [Nicholas] and his daughter [Mary] like to read poems together.
[{('Glen', 'father', 'Nicholas'): [('Glen', 'sister', 'Mary'), ('Mary', 'father', 'Nicholas')]}]
['sister', 'father']