[Roy] took his grandson [Michael] to the zoo. [Michael]'s brother [William] went to the aquarium instead.
('Roy', 'William')
[Roy] took his grandson [Michael] to the zoo. [Michael]'s brother [William] went to the aquarium instead.
[{('Roy', 'grandson', 'William'): [('Roy', 'grandson', 'Michael'), ('Michael', 'brother', 'William')]}]