[Pamela] was playing in the sandbox with her brother [Chris]. [Chris] tripped his brother [Charles] in the living room. [Frances] kept her grandson [Charles] last weekend so his parents could go to a concert.
('Pamela', 'Frances')
[Pamela] was playing in the sandbox with her brother [Chris]. [Chris] tripped his brother [Charles] in the living room. [Frances] kept her grandson [Charles] last weekend so his parents could go to a concert.
[{('Pamela', 'grandmother', 'Frances'): [('Pamela', 'brother', 'Charles'), ('Charles', 'grandmother', 'Frances')]}, {('Pamela', 'brother', 'Charles'): [('Pamela', 'brother', 'Chris'), ('Chris', 'brother', 'Charles')]}]
['brother', 'brother', 'grandmother']