[Allan] and his father [Robert] went to the zoo. [Robert]'s sister [Tracy] was supposed to come with them, but could n't. [Shantel] played golf with her son [Louis]. [Louis]'s sister [Tracy] watched with delight.
('Allan', 'Shantel')
[Allan] and his father [Robert] went to the zoo. [Robert]'s sister [Tracy] was supposed to come with them, but could n't. [Shantel] played golf with her son [Louis]. [Louis]'s sister [Tracy] watched with delight.
[{('Allan', 'grandmother', 'Shantel'): [('Allan', 'father', 'Robert'), ('Robert', 'mother', 'Shantel')]}, {('Robert', 'mother', 'Shantel'): [('Robert', 'sister', 'Tracy'), ('Tracy', 'mother', 'Shantel')]}, {('Tracy', 'mother', 'Shantel'): [('Tracy', 'brother', 'Louis'), ('Louis', 'mother', 'Shantel')]}]
['father', 'sister', 'brother', 'mother']