[Bettie] is taking her brother [Bobby] out for a late dinner. [Tracy], [Bobby]'s mother, is home with a cold. [Tracy] looked all over the house for her son [Bobby], but could n't find him. That's because [Bobby] was outside in the back yard, playing baseball with his brother [Aaron].
('Aaron', 'Bettie')
[Tracy] looked all over the house for her son [Bobby], but could n't find him. That's because [Bobby] was outside in the back yard, playing baseball with his brother [Aaron]. [Bettie] is taking her brother [Bobby] out for a late dinner. [Tracy], [Bobby]'s mother, is home with a cold.
[{('Aaron', 'sister', 'Bettie'): [('Aaron', 'mother', 'Tracy'), ('Tracy', 'daughter', 'Bettie')]}, {('Aaron', 'mother', 'Tracy'): [('Aaron', 'brother', 'Bobby'), ('Bobby', 'mother', 'Tracy')]}, {('Tracy', 'daughter', 'Bettie'): [('Tracy', 'son', 'Bobby'), ('Bobby', 'sister', 'Bettie')]}]
['brother', 'mother', 'son', 'sister']