[Pedro] took his daughter [Heather] to the zoo on Saturday. [Pedro]'s wife [Dorothy] could n't come as she had to work that day. [Robert] went his brother to pick up his brother's daughter [Heather] from a birthday party. [Robert] decided to take his son, [Mario], on a ski vacation.
('Dorothy', 'Mario')
[Pedro] took his daughter [Heather] to the zoo on Saturday. [Pedro]'s wife [Dorothy] could n't come as she had to work that day. [Robert] went his brother to pick up his brother's daughter [Heather] from a birthday party. [Robert] decided to take his son, [Mario], on a ski vacation.
[{('Dorothy', 'nephew', 'Mario'): [('Dorothy', 'brother', 'Robert'), ('Robert', 'son', 'Mario')]}, {('Dorothy', 'brother', 'Robert'): [('Dorothy', 'daughter', 'Heather'), ('Heather', 'uncle', 'Robert')]}, {('Dorothy', 'daughter', 'Heather'): [('Dorothy', 'husband', 'Pedro'), ('Pedro', 'daughter', 'Heather')]}]
['husband', 'daughter', 'uncle', 'son']