[Wayne] decided to take his son, [Jeff], on a ski vacation. [Wayne] and his son [Robert] went to the park to look for different kinds of birds.
('Robert', 'Jeff')
[Wayne] and his son [Robert] went to the park to look for different kinds of birds. [Wayne] decided to take his son, [Jeff], on a ski vacation.
[{('Robert', 'brother', 'Jeff'): [('Robert', 'father', 'Wayne'), ('Wayne', 'son', 'Jeff')]}]
['father', 'son']