[Robert] called his brother, [Antonio], to confirm when [Antonio]'s sister, [Dorothy], was coming to the dinner. [Robert] took his sister [Beverly] to the movies with him to see the new Star Wars film. [Beverly] was talking about food with her sister [Tracy].
('Dorothy', 'Tracy')
[Robert] called his brother, [Antonio], to confirm when [Antonio]'s sister, [Dorothy], was coming to the dinner. [Robert] took his sister [Beverly] to the movies with him to see the new Star Wars film. [Beverly] was talking about food with her sister [Tracy].
[{('Dorothy', 'sister', 'Tracy'): [('Dorothy', 'sister', 'Beverly'), ('Beverly', 'sister', 'Tracy')]}, {('Dorothy', 'sister', 'Beverly'): [('Dorothy', 'brother', 'Robert'), ('Robert', 'sister', 'Beverly')]}, {('Dorothy', 'brother', 'Robert'): [('Dorothy', 'brother', 'Antonio'), ('Antonio', 'brother', 'Robert')]}]
['brother', 'brother', 'sister', 'sister']