story: [Preston] is [Stacy]'s father. [James] has two siblings. His brother [Preston] and sister [Nancy]
query: ('Preston', 'Nancy')
clean_story: [James] has two siblings. His brother [Preston] and sister [Nancy]
proof_state: [{('Preston', 'sister', 'Nancy'): [('Preston', 'brother', 'James'), ('James', 'sister', 'Nancy')]}]