[Robert] went skiing with his brother [Pedro]. [Pedro]'s sister [Tracy] watched from the ski lodge. [Robert]'s mother [Shantel] made a cake for his birthday and her other son [Louis] ate a piece of it.
('Tracy', 'Louis')
[Robert] went skiing with his brother [Pedro]. [Pedro]'s sister [Tracy] watched from the ski lodge. [Robert]'s mother [Shantel] made a cake for his birthday and her other son [Louis] ate a piece of it.
[{('Tracy', 'brother', 'Louis'): [('Tracy', 'brother', 'Pedro'), ('Pedro', 'brother', 'Louis')]}, {('Pedro', 'brother', 'Louis'): [('Pedro', 'brother', 'Robert'), ('Robert', 'brother', 'Louis')]}, {('Robert', 'brother', 'Louis'): [('Robert', 'mother', 'Shantel'), ('Shantel', 'son', 'Louis')]}]
['brother', 'brother', 'mother', 'son']