[Dorothy] is a sister of [Antonio]. [Pedro] often goes out for lunch with his sister, [Marie]. [Dorothy]'s brother [Louis] took her to the fair when she was little. [Louis] also brought his brother [Pedro].
('Antonio', 'Marie')
[Dorothy] is a sister of [Antonio]. [Dorothy]'s brother [Louis] took her to the fair when she was little. [Louis] also brought his brother [Pedro]. [Pedro] often goes out for lunch with his sister, [Marie].
[{('Antonio', 'sister', 'Marie'): [('Antonio', 'sister', 'Dorothy'), ('Dorothy', 'sister', 'Marie')]}, {('Dorothy', 'sister', 'Marie'): [('Dorothy', 'brother', 'Louis'), ('Louis', 'sister', 'Marie')]}, {('Louis', 'sister', 'Marie'): [('Louis', 'brother', 'Pedro'), ('Pedro', 'sister', 'Marie')]}]
['sister', 'brother', 'brother', 'sister']