[Mario] asked his father, [Robert], to help him with his math homework. [Robert] could n't, because he was lousy at math himself. [John] and his wife [Angelica] are newlyweds. They are on their honeymoon, having a wonderful time. [Mario] liked playing with his brother [Ronald] more than anyone else. This made [Angelica] jealous of her brother [Ronald].
('John', 'Robert')
[John] and his wife [Angelica] are newlyweds. They are on their honeymoon, having a wonderful time. [Mario] liked playing with his brother [Ronald] more than anyone else. This made [Angelica] jealous of her brother [Ronald]. [Mario] asked his father, [Robert], to help him with his math homework. [Robert] could n't, because he was lousy at math himself.
[{('John', 'father-in-law', 'Robert'): [('John', 'wife', 'Angelica'), ('Angelica', 'father', 'Robert')]}, {('Angelica', 'father', 'Robert'): [('Angelica', 'brother', 'Ronald'), ('Ronald', 'father', 'Robert')]}, {('Ronald', 'father', 'Robert'): [('Ronald', 'brother', 'Mario'), ('Mario', 'father', 'Robert')]}]
['wife', 'brother', 'brother', 'father']