[Chris] is going to the arcade with his sister, [Martha]. [Lena] took her son [Chris] to the football game. [Martha] does n't like having to babysit her younger brother, [Charles].
('Lena', 'Charles')
[Lena] took her son [Chris] to the football game. [Chris] is going to the arcade with his sister, [Martha]. [Martha] does n't like having to babysit her younger brother, [Charles].
[{('Lena', 'son', 'Charles'): [('Lena', 'son', 'Chris'), ('Chris', 'brother', 'Charles')]}, {('Chris', 'brother', 'Charles'): [('Chris', 'sister', 'Martha'), ('Martha', 'brother', 'Charles')]}]
['son', 'sister', 'brother']