[Robert] bought his daughter [Lizzie] and son [Ronald] a gift. [Lizzie]'s sister [Angelica] did n't get anything. [Mario]'s sister [Angelica] asked him for some help planting her garden.
('Ronald', 'Mario')
[Robert] bought his daughter [Lizzie] and son [Ronald] a gift. [Lizzie]'s sister [Angelica] did n't get anything. [Mario]'s sister [Angelica] asked him for some help planting her garden.
[{('Ronald', 'brother', 'Mario'): [('Ronald', 'sister', 'Lizzie'), ('Lizzie', 'brother', 'Mario')]}, {('Lizzie', 'brother', 'Mario'): [('Lizzie', 'father', 'Robert'), ('Robert', 'son', 'Mario')]}, {('Robert', 'son', 'Mario'): [('Robert', 'daughter', 'Angelica'), ('Angelica', 'brother', 'Mario')]}]
['sister', 'father', 'daughter', 'brother']