[Jerry]'s father, [George], bought him some ice cream. [Douglas] helped his brother, [Jerry], study for the chemistry exam.
('Douglas', 'George')
[Douglas] helped his brother, [Jerry], study for the chemistry exam. [Jerry]'s father, [George], bought him some ice cream.
[{('Douglas', 'father', 'George'): [('Douglas', 'brother', 'Jerry'), ('Jerry', 'father', 'George')]}]
['brother', 'father']