While [Pedro] was playing soccer with his son [Heather], his wife [Dorothy] took her daughter [Annie] to the cinema. [Annie] took her mother, [Dorothy], out for lunch.
('Heather', 'Dorothy')
While [Pedro] was playing soccer with his son [Heather], his wife [Dorothy] took her daughter [Annie] to the cinema. [Annie] took her mother, [Dorothy], out for lunch.
[{('Heather', 'mother', 'Dorothy'): [('Heather', 'sister', 'Annie'), ('Annie', 'mother', 'Dorothy')]}, {('Heather', 'sister', 'Annie'): [('Heather', 'father', 'Pedro'), ('Pedro', 'daughter', 'Annie')]}, {('Pedro', 'daughter', 'Annie'): [('Pedro', 'wife', 'Dorothy'), ('Dorothy', 'daughter', 'Annie')]}]
['father', 'wife', 'daughter', 'mother']