[Lillian] took her son [John] to the park for the afternoon. [John] invited his uncle [Dale] to dinner
('Lillian', 'Dale')
[Lillian] took her son [John] to the park for the afternoon. [John] invited his uncle [Dale] to dinner
[{('Lillian', 'brother', 'Dale'): [('Lillian', 'son', 'John'), ('John', 'uncle', 'Dale')]}]
['son', 'uncle']