story: [Christopher] took his sister [Alma] out to dinner for her birthday. [Chad] is son of [Alma].
query: ('Chad', 'Christopher')
clean_story: [Chad] is son of [Alma]. [Christopher] took his sister [Alma] out to dinner for her birthday.
proof_state: [{('Chad', 'uncle', 'Christopher'): [('Chad', 'mother', 'Alma'), ('Alma', 'brother', 'Christopher')]}]