[James] played catch with his son [Joshua]. [James]'s other son [Francisco] does n't play baseball. [Joshua] and his sister [David] are going for a walk.
('Francisco', 'David')
[James] played catch with his son [Joshua]. [James]'s other son [Francisco] does n't play baseball. [Joshua] and his sister [David] are going for a walk.
[{('Francisco', 'sister', 'David'): [('Francisco', 'father', 'James'), ('James', 'daughter', 'David')]}, {('James', 'daughter', 'David'): [('James', 'son', 'Joshua'), ('Joshua', 'sister', 'David')]}]
['father', 'son', 'sister']