[Harold] bought a book for his son [Robert]. [Pedro] loves his daughter [Annie]. [Annie] does n't like her brother [Roberto]. [Roberto] went fishing with his uncle [Robert].
('Pedro', 'Harold')
[Pedro] loves his daughter [Annie]. [Annie] does n't like her brother [Roberto]. [Roberto] went fishing with his uncle [Robert]. [Harold] bought a book for his son [Robert].
[{('Pedro', 'father', 'Harold'): [('Pedro', 'brother', 'Robert'), ('Robert', 'father', 'Harold')]}, {('Pedro', 'brother', 'Robert'): [('Pedro', 'son', 'Roberto'), ('Roberto', 'uncle', 'Robert')]}, {('Pedro', 'son', 'Roberto'): [('Pedro', 'daughter', 'Annie'), ('Annie', 'brother', 'Roberto')]}]
['daughter', 'brother', 'uncle', 'father']