[Arthur] who is [Lois]'s son made the basketball team. [Mary] who is the grandmother of [Arthur] will attend the game.
('Lois', 'Mary')
[Arthur] who is [Lois]'s son made the basketball team. [Mary] who is the grandmother of [Arthur] will attend the game.
[{('Lois', 'mother', 'Mary'): [('Lois', 'son', 'Arthur'), ('Arthur', 'grandmother', 'Mary')]}]