[Louis] took his son [Michael] to soccer practice. [Robert]'s sister [Dorothy] asked him for some help planting her garden. [Michael]'s father has a sister named [Dorothy]. [Tracy] went on a vacation with her brother [Louis].
('Tracy', 'Robert')
[Tracy] went on a vacation with her brother [Louis]. [Louis] took his son [Michael] to soccer practice. [Michael]'s father has a sister named [Dorothy]. [Robert]'s sister [Dorothy] asked him for some help planting her garden.
[{('Tracy', 'brother', 'Robert'): [('Tracy', 'brother', 'Louis'), ('Louis', 'brother', 'Robert')]}, {('Louis', 'brother', 'Robert'): [('Louis', 'sister', 'Dorothy'), ('Dorothy', 'brother', 'Robert')]}, {('Louis', 'sister', 'Dorothy'): [('Louis', 'son', 'Michael'), ('Michael', 'aunt', 'Dorothy')]}]
['brother', 'son', 'aunt', 'brother']