[Charles] helped his brother, [Chris], study for the chemistry exam. [Lena] took her son [Charles] and her daughter [Martha] to get fast food because they were well behaved.
('Martha', 'Chris')
[Lena] took her son [Charles] and her daughter [Martha] to get fast food because they were well behaved. [Charles] helped his brother, [Chris], study for the chemistry exam.
[{('Martha', 'brother', 'Chris'): [('Martha', 'brother', 'Charles'), ('Charles', 'brother', 'Chris')]}, {('Martha', 'brother', 'Charles'): [('Martha', 'mother', 'Lena'), ('Lena', 'son', 'Charles')]}]
['mother', 'son', 'brother']