[Nancy] has been waiting around all day for her son, [Kevin]. [Nancy] invited her father [Clarence] to dinner.
('Clarence', 'Kevin')
[Nancy] invited her father [Clarence] to dinner. [Nancy] has been waiting around all day for her son, [Kevin].
[{('Clarence', 'grandson', 'Kevin'): [('Clarence', 'daughter', 'Nancy'), ('Nancy', 'son', 'Kevin')]}]
['daughter', 'son']