story: [Crystal] took her son [Bernard] to the football game. [Crystal] and [Nancy], both sisters, are feeling frazzled after [Nancy] gave birth to [Fletcher], a son.
query: ('Crystal', 'Fletcher')
clean_story: [Crystal] and [Nancy], both sisters, are feeling frazzled after [Nancy] gave birth to [Fletcher], a son.
proof_state: [{('Crystal', 'nephew', 'Fletcher'): [('Crystal', 'sister', 'Nancy'), ('Nancy', 'son', 'Fletcher')]}]