[Samuel] went to a piano concert with his aunt [Marie]. [Beverly]'s son, [Samuel], was busy with school activities and forgot to meet his sister. [Dorothy] asked her sister [Tracy] to play with her. [Tracy] did n't want to, she wanted to play with her sister [Beverly] instead.
('Dorothy', 'Marie')
[Dorothy] asked her sister [Tracy] to play with her. [Tracy] did n't want to, she wanted to play with her sister [Beverly] instead. [Beverly]'s son, [Samuel], was busy with school activities and forgot to meet his sister. [Samuel] went to a piano concert with his aunt [Marie].
[{('Dorothy', 'sister', 'Marie'): [('Dorothy', 'sister', 'Beverly'), ('Beverly', 'sister', 'Marie')]}, {('Beverly', 'sister', 'Marie'): [('Beverly', 'son', 'Samuel'), ('Samuel', 'aunt', 'Marie')]}, {('Dorothy', 'sister', 'Beverly'): [('Dorothy', 'sister', 'Tracy'), ('Tracy', 'sister', 'Beverly')]}]
['sister', 'sister', 'son', 'aunt']