[Nancy] took her father [Clarence] out to dinner one day and also brought along her son [Kevin].
('Kevin', 'Clarence')
[Nancy] took her father [Clarence] out to dinner one day and also brought along her son [Kevin].
[{('Kevin', 'grandfather', 'Clarence'): [('Kevin', 'mother', 'Nancy'), ('Nancy', 'father', 'Clarence')]}]
['mother', 'father']