story: [Michael] took his son [Russell] out for ice cream. [Michael]'s son [Donald], was still in school.
query: ('Donald', 'Russell')
clean_story: [Michael] took his son [Russell] out for ice cream. [Michael]'s son [Donald], was still in school.
proof_state: [{('Donald', 'brother', 'Russell'): [('Donald', 'father', 'Michael'), ('Michael', 'son', 'Russell')]}]