[Dale] and his son [Travis] went to visit [Dale]'s sister [Nancy] Saturday. They ate lunch and played video games.
('Nancy', 'Travis')
[Dale] and his son [Travis] went to visit [Dale]'s sister [Nancy] Saturday. They ate lunch and played video games.
[{('Nancy', 'nephew', 'Travis'): [('Nancy', 'brother', 'Dale'), ('Dale', 'son', 'Travis')]}]
['brother', 'son']