story: [Richard] and his mother, [Carol], went to the zoo. Meanwhile, [Richard]'s son, [Mark], and [Carol]'s son, [Michael], went to the race track. [Carol] was unhappy with her son, [David], and his grades. She enlisted a tutor to help him.
query: ('Mark', 'Michael')
clean_story: [Richard] and his mother, [Carol], went to the zoo. Meanwhile, [Richard]'s son, [Mark], and [Carol]'s son, [Michael], went to the race track.
proof_state: [{('Mark', 'son', 'Michael'): [('Mark', 'son', 'Richard'), ('Richard', 'brother', 'Michael')]}, {('Richard', 'brother', 'Michael'): [('Richard', 'mother', 'Carol'), ('Carol', 'son', 'Michael')]}]