[Brent] was going out to dinner with his sister [Laura] when he received a call from his grandfather [Roy].
('Laura', 'Roy')
[Brent] was going out to dinner with his sister [Laura] when he received a call from his grandfather [Roy].
[{('Laura', 'grandfather', 'Roy'): [('Laura', 'brother', 'Brent'), ('Brent', 'grandfather', 'Roy')]}]