[George] has a son named [John] that looks exactly like him. [Ann] went on a vacation with her brother [John].
('Ann', 'George')
[Ann] went on a vacation with her brother [John]. [George] has a son named [John] that looks exactly like him.
[{('Ann', 'father', 'George'): [('Ann', 'brother', 'John'), ('John', 'father', 'George')]}]
['brother', 'father']