[Pedro]'s son [Roberto] entered rehab for the ninth time at the age of thirty. [Tracy] and her brother [Robert] were having a wonderful time at Disneyland. [Tracy] was sewing a sweater for her sister [Dorothy]. [Roberto] was enjoying the delicious meal prepared by his mother [Dorothy].
('Pedro', 'Robert')
[Pedro]'s son [Roberto] entered rehab for the ninth time at the age of thirty. [Roberto] was enjoying the delicious meal prepared by his mother [Dorothy]. [Tracy] was sewing a sweater for her sister [Dorothy]. [Tracy] and her brother [Robert] were having a wonderful time at Disneyland.
[{('Pedro', 'brother', 'Robert'): [('Pedro', 'son', 'Roberto'), ('Roberto', 'uncle', 'Robert')]}, {('Roberto', 'uncle', 'Robert'): [('Roberto', 'mother', 'Dorothy'), ('Dorothy', 'brother', 'Robert')]}, {('Dorothy', 'brother', 'Robert'): [('Dorothy', 'sister', 'Tracy'), ('Tracy', 'brother', 'Robert')]}]
['son', 'mother', 'sister', 'brother']