[Robert] and kyle are brothers. They went out to eat with [Pedro]'s sister [Tracy]. [Tracy] went out to dinner with her sister [Dorothy], and [Dorothy]'s daughter [Rebecca].
('Robert', 'Rebecca')
[Robert] and kyle are brothers. They went out to eat with [Pedro]'s sister [Tracy]. [Tracy] went out to dinner with her sister [Dorothy], and [Dorothy]'s daughter [Rebecca].
[{('Robert', 'niece', 'Rebecca'): [('Robert', 'sister', 'Dorothy'), ('Dorothy', 'daughter', 'Rebecca')]}, {('Robert', 'sister', 'Dorothy'): [('Robert', 'sister', 'Tracy'), ('Tracy', 'sister', 'Dorothy')]}, {('Robert', 'sister', 'Tracy'): [('Robert', 'brother', 'Pedro'), ('Pedro', 'sister', 'Tracy')]}]
['brother', 'sister', 'sister', 'daughter']