[Dale] played catch with his son [Tony]. [Dale]'s other son [James] does n't play baseball.
('James', 'Tony')
[Dale] played catch with his son [Tony]. [Dale]'s other son [James] does n't play baseball.
[{('James', 'brother', 'Tony'): [('James', 'father', 'Dale'), ('Dale', 'son', 'Tony')]}]
['father', 'son']