[Adan] asked his father, [John], to help him with his math homework. [John] could n't, because he was lousy at math himself. [Robert] is a man with a brother named [Adan].
('Robert', 'John')
[Robert] is a man with a brother named [Adan]. [Adan] asked his father, [John], to help him with his math homework. [John] could n't, because he was lousy at math himself.
[{('Robert', 'father', 'John'): [('Robert', 'brother', 'Adan'), ('Adan', 'father', 'John')]}]