[John] asked his mother [Marie] where babies came from. [Marie] told him they came from the stork. [Allan] made a pie for his sister [Elsie]. He learned the recipe from his mother [Marie]. [John] asked his father, [Robert] to help him build a birdhouse.
('Robert', 'Elsie')
[John] asked his father, [Robert] to help him build a birdhouse. [John] asked his mother [Marie] where babies came from. [Marie] told him they came from the stork. [Allan] made a pie for his sister [Elsie]. He learned the recipe from his mother [Marie].
[{('Robert', 'daughter', 'Elsie'): [('Robert', 'son', 'John'), ('John', 'sister', 'Elsie')]}, {('John', 'sister', 'Elsie'): [('John', 'mother', 'Marie'), ('Marie', 'daughter', 'Elsie')]}, {('Marie', 'daughter', 'Elsie'): [('Marie', 'son', 'Allan'), ('Allan', 'sister', 'Elsie')]}]
['son', 'mother', 'son', 'sister']