[Dale] is a man with a son named [Travis]. [James] bought a book for his father [Dale].
('Travis', 'James')
[Dale] is a man with a son named [Travis]. [James] bought a book for his father [Dale].
[{('Travis', 'brother', 'James'): [('Travis', 'father', 'Dale'), ('Dale', 'son', 'James')]}]
['father', 'son']