[Lillian] was helping her son [Jerry] complete math homework when it reminded her how her father [Clarence] used to help her finish homework, too.
('Jerry', 'Clarence')
[Lillian] was helping her son [Jerry] complete math homework when it reminded her how her father [Clarence] used to help her finish homework, too.
[{('Jerry', 'grandfather', 'Clarence'): [('Jerry', 'mother', 'Lillian'), ('Lillian', 'father', 'Clarence')]}]
['mother', 'father']