[Tracy] misses her father [Harold] when she is at school. [Robert] made a sandwich for his son [Mario]. [Mario]'s brother [John] ate an apple instead. [John] wanted to play at the park so his mother got her sister, [Tracy], to take him.
('Robert', 'Harold')
[Robert] made a sandwich for his son [Mario]. [Mario]'s brother [John] ate an apple instead. [John] wanted to play at the park so his mother got her sister, [Tracy], to take him. [Tracy] misses her father [Harold] when she is at school.
[{('Robert', 'father', 'Harold'): [('Robert', 'sister', 'Tracy'), ('Tracy', 'father', 'Harold')]}, {('Robert', 'sister', 'Tracy'): [('Robert', 'son', 'John'), ('John', 'aunt', 'Tracy')]}, {('Robert', 'son', 'John'): [('Robert', 'son', 'Mario'), ('Mario', 'brother', 'John')]}]
['son', 'brother', 'aunt', 'father']