story: [Kevin] helped his brother, [Vincent], study for the chemistry exam. [Dorothy]'s son, [Kevin], recently started a pawn shop.
query: ('Dorothy', 'Vincent')
clean_story: [Dorothy]'s son, [Kevin], recently started a pawn shop. [Kevin] helped his brother, [Vincent], study for the chemistry exam.
proof_state: [{('Dorothy', 'son', 'Vincent'): [('Dorothy', 'son', 'Kevin'), ('Kevin', 'brother', 'Vincent')]}]