[Lynn] took her son [Clarence] shopping for new school clothes. They had a good time. [Joshua] is frustrated teaching his son how to drive. His son is [Clarence]. [Lena] was sewing a sweater for her sister [Lynn].
('Joshua', 'Lena')
[Joshua] is frustrated teaching his son how to drive. His son is [Clarence]. [Lynn] took her son [Clarence] shopping for new school clothes. They had a good time. [Lena] was sewing a sweater for her sister [Lynn].
[{('Joshua', 'sister', 'Lena'): [('Joshua', 'son', 'Clarence'), ('Clarence', 'aunt', 'Lena')]}, {('Clarence', 'aunt', 'Lena'): [('Clarence', 'mother', 'Lynn'), ('Lynn', 'sister', 'Lena')]}]
['son', 'mother', 'sister']