[Travis] asked his father, [Dale], to help him with his math homework. [Dale] could n't, because he was lousy at math himself. [Dale] wanted to buy his mother, [Ashley], a birthday present. But he did n't know what to get her.
('Travis', 'Ashley')
[Travis] asked his father, [Dale], to help him with his math homework. [Dale] could n't, because he was lousy at math himself. [Dale] wanted to buy his mother, [Ashley], a birthday present. But he did n't know what to get her.
[{('Travis', 'grandmother', 'Ashley'): [('Travis', 'father', 'Dale'), ('Dale', 'mother', 'Ashley')]}]
['father', 'mother']