[John] took his sister [April] out to dinner for her birthday. [George] wanted his son, [John], to go fishing with him.
('April', 'George')
[John] took his sister [April] out to dinner for her birthday. [George] wanted his son, [John], to go fishing with him.
[{('April', 'father', 'George'): [('April', 'brother', 'John'), ('John', 'father', 'George')]}]
['brother', 'father']