[Mary] gave her brother [Glen] a new sweater for Christmas. [Nicholas] and his son [Glen] went to the park to look for different kinds of birds.
('Mary', 'Nicholas')
[Mary] gave her brother [Glen] a new sweater for Christmas. [Nicholas] and his son [Glen] went to the park to look for different kinds of birds.
[{('Mary', 'father', 'Nicholas'): [('Mary', 'brother', 'Glen'), ('Glen', 'father', 'Nicholas')]}]
['brother', 'father']