[Roberto] is a sibling of [James]. [Pedro] went to pick up his son [Roberto] from the baseball practice. [Rebecca] went over to her uncle [Robert]'s house for dinner. [Robert] was a gourmet cook, and tonight he made a delicious crown of lamb. [James] and his sister [Rebecca] went to the park.
('Pedro', 'Robert')
[Pedro] went to pick up his son [Roberto] from the baseball practice. [Roberto] is a sibling of [James]. [James] and his sister [Rebecca] went to the park. [Rebecca] went over to her uncle [Robert]'s house for dinner. [Robert] was a gourmet cook, and tonight he made a delicious crown of lamb.
[{('Pedro', 'brother', 'Robert'): [('Pedro', 'daughter', 'Rebecca'), ('Rebecca', 'uncle', 'Robert')]}, {('Pedro', 'daughter', 'Rebecca'): [('Pedro', 'son', 'Roberto'), ('Roberto', 'sister', 'Rebecca')]}, {('Roberto', 'sister', 'Rebecca'): [('Roberto', 'brother', 'James'), ('James', 'sister', 'Rebecca')]}]
['son', 'brother', 'sister', 'uncle']