[Harold] took his son [Robert] to baseball practice. [Harold]'s daughter [Dorothy] was busy at soccer practice. [Dorothy] baked a cake for her son [Jerome]. [Jerome] was happy to see his aunt [Tracy].
('Robert', 'Tracy')
[Harold] took his son [Robert] to baseball practice. [Harold]'s daughter [Dorothy] was busy at soccer practice. [Dorothy] baked a cake for her son [Jerome]. [Jerome] was happy to see his aunt [Tracy].
[{('Robert', 'sister', 'Tracy'): [('Robert', 'sister', 'Dorothy'), ('Dorothy', 'sister', 'Tracy')]}, {('Robert', 'sister', 'Dorothy'): [('Robert', 'father', 'Harold'), ('Harold', 'daughter', 'Dorothy')]}, {('Dorothy', 'sister', 'Tracy'): [('Dorothy', 'son', 'Jerome'), ('Jerome', 'aunt', 'Tracy')]}]
['father', 'daughter', 'son', 'aunt']