[James] took his daughter [David] to see a movie. [David]'s sister [Lena] was sad because she was grounded and was not allowed to go. [Lena]'s son, [Charles], was busy with school activities and forgot to meet his sister.
('James', 'Charles')
[James] took his daughter [David] to see a movie. [David]'s sister [Lena] was sad because she was grounded and was not allowed to go. [Lena]'s son, [Charles], was busy with school activities and forgot to meet his sister.
[{('James', 'grandson', 'Charles'): [('James', 'daughter', 'Lena'), ('Lena', 'son', 'Charles')]}, {('James', 'daughter', 'Lena'): [('James', 'daughter', 'David'), ('David', 'sister', 'Lena')]}]
['daughter', 'sister', 'son']