[Brent] invited his uncle [Herman] to dinner [Martha] takes her son [Brent] to the park every Saturday.
('Martha', 'Herman')
[Martha] takes her son [Brent] to the park every Saturday. [Brent] invited his uncle [Herman] to dinner
[{('Martha', 'brother', 'Herman'): [('Martha', 'son', 'Brent'), ('Brent', 'uncle', 'Herman')]}]