story: [Joe] and his brother, [Lewis], went to visit [Joe]'s grandfather, [Jason].
query: ('Lewis', 'Jason')
clean_story: [Joe] and his brother, [Lewis], went to visit [Joe]'s grandfather, [Jason].
proof_state: [{('Lewis', 'grandfather', 'Jason'): [('Lewis', 'brother', 'Joe'), ('Joe', 'grandfather', 'Jason')]}]