[Bettie] was playing in the sandbox with her brother [Bernardo]. [Laura] is taking her brother [Bernardo] out for a late dinner. [Tracy], [Bernardo]'s mother, is home with a cold. [Tracy] bought a new video game for her son [Bernardo].
('Bettie', 'Laura')
[Bettie] was playing in the sandbox with her brother [Bernardo]. [Tracy] bought a new video game for her son [Bernardo]. [Laura] is taking her brother [Bernardo] out for a late dinner. [Tracy], [Bernardo]'s mother, is home with a cold.
[{('Bettie', 'sister', 'Laura'): [('Bettie', 'mother', 'Tracy'), ('Tracy', 'daughter', 'Laura')]}, {('Tracy', 'daughter', 'Laura'): [('Tracy', 'son', 'Bernardo'), ('Bernardo', 'sister', 'Laura')]}, {('Bettie', 'mother', 'Tracy'): [('Bettie', 'brother', 'Bernardo'), ('Bernardo', 'mother', 'Tracy')]}]
['brother', 'mother', 'son', 'sister']