[Douglas]'s grandfather [Clarence] and brother [Jerry] all went to a hockey game after dinner.
('Jerry', 'Clarence')
[Douglas]'s grandfather [Clarence] and brother [Jerry] all went to a hockey game after dinner.
[{('Jerry', 'grandfather', 'Clarence'): [('Jerry', 'brother', 'Douglas'), ('Douglas', 'grandfather', 'Clarence')]}]
['brother', 'grandfather']