[Robert] was having a great dinner with his brother [Louis]. [Dorothy], [Robert]'s sister, recommended the new Italian restaurant. [Beverly], [Dorothy]'s sister, declined the dinner invitation because she dislikes Italian food. [Beverly]'s brother [Antonio] was going to be the star in the new show.
('Louis', 'Antonio')
[Robert] was having a great dinner with his brother [Louis]. [Dorothy], [Robert]'s sister, recommended the new Italian restaurant. [Beverly], [Dorothy]'s sister, declined the dinner invitation because she dislikes Italian food. [Beverly]'s brother [Antonio] was going to be the star in the new show.
[{('Louis', 'brother', 'Antonio'): [('Louis', 'sister', 'Dorothy'), ('Dorothy', 'brother', 'Antonio')]}, {('Louis', 'sister', 'Dorothy'): [('Louis', 'brother', 'Robert'), ('Robert', 'sister', 'Dorothy')]}, {('Dorothy', 'brother', 'Antonio'): [('Dorothy', 'sister', 'Beverly'), ('Beverly', 'brother', 'Antonio')]}]
['brother', 'sister', 'sister', 'brother']