story: [Francisco] bought a book for his father [Alfred]. [Peter] and his brother [Alfred] were rarely seen apart. [Carol] loves playing checkers with her sister's son. His name is [Francisco]. [Peter] is taking his son [Erik] out for coffee.
query: ('Peter', 'Carol')
clean_story: [Peter] and his brother [Alfred] were rarely seen apart. [Francisco] bought a book for his father [Alfred]. [Carol] loves playing checkers with her sister's son. His name is [Francisco].
proof_state: [{('Peter', 'sister', 'Carol'): [('Peter', 'brother', 'Alfred'), ('Alfred', 'sister', 'Carol')]}, {('Alfred', 'sister', 'Carol'): [('Alfred', 'son', 'Francisco'), ('Francisco', 'aunt', 'Carol')]}]