[Robert] took his son [Ronald] out for ice cream. [Robert]'s son [Allan], was still in school. [Ronald] was sad to learn that his sister [Michelle] was not going to make it to dinner like they had planned. [Ronald] and his sister [Michelle] went to brunch today at the new diner.
('Allan', 'Ronald')
[Robert] took his son [Ronald] out for ice cream. [Robert]'s son [Allan], was still in school. [Ronald] was sad to learn that his sister [Michelle] was not going to make it to dinner like they had planned. [Ronald] and his sister [Michelle] went to brunch today at the new diner.
[{('Allan', 'brother', 'Ronald'): [('Allan', 'sister', 'Michelle'), ('Michelle', 'brother', 'Ronald')]}, {('Allan', 'sister', 'Michelle'): [('Allan', 'father', 'Robert'), ('Robert', 'daughter', 'Michelle')]}, {('Robert', 'daughter', 'Michelle'): [('Robert', 'son', 'Ronald'), ('Ronald', 'sister', 'Michelle')]}]
['father', 'son', 'sister', 'brother']