story: [Joe] is the grandson of [Jason] and [Lewis] is [Joe]'s brother.
query: ('Lewis', 'Jason')
clean_story: [Joe] is the grandson of [Jason] and [Lewis] is [Joe]'s brother.
proof_state: [{('Lewis', 'grandfather', 'Jason'): [('Lewis', 'brother', 'Joe'), ('Joe', 'grandfather', 'Jason')]}]