[George] took his sister [Amy] and his brother [Dale] out to dinner for their birthday last night and they had a great time.
('Dale', 'Amy')
[George] took his sister [Amy] and his brother [Dale] out to dinner for their birthday last night and they had a great time.
[{('Dale', 'sister', 'Amy'): [('Dale', 'brother', 'George'), ('George', 'sister', 'Amy')]}]
['brother', 'sister']