[Clarence] invited his Aunt [David] to come to his graduation party. [James] took his son [Joshua] out to dinner to celebrate his promotion. [Joshua] brought his son, [Clarence], along to celebrate.
('James', 'David')
[James] took his son [Joshua] out to dinner to celebrate his promotion. [Joshua] brought his son, [Clarence], along to celebrate. [Clarence] invited his Aunt [David] to come to his graduation party.
[{('James', 'daughter', 'David'): [('James', 'son', 'Joshua'), ('Joshua', 'sister', 'David')]}, {('Joshua', 'sister', 'David'): [('Joshua', 'son', 'Clarence'), ('Clarence', 'aunt', 'David')]}]
['son', 'son', 'aunt']