story: [Peter] likes to go fishing with his sister. Her name is [Lisbeth]. [Michelle] invited her father [Peter] to dinner. [Ellen] stayed with his grandmother [Sandra] last summer on her farm. He had a great time. [Lisbeth] and her daughter [Ellen] went out to dinner.
query: ('Peter', 'Sandra')
clean_story: [Peter] likes to go fishing with his sister. Her name is [Lisbeth]. [Lisbeth] and her daughter [Ellen] went out to dinner. [Ellen] stayed with his grandmother [Sandra] last summer on her farm. He had a great time.
proof_state: [{('Peter', 'mother', 'Sandra'): [('Peter', 'sister', 'Lisbeth'), ('Lisbeth', 'mother', 'Sandra')]}, {('Lisbeth', 'mother', 'Sandra'): [('Lisbeth', 'daughter', 'Ellen'), ('Ellen', 'grandmother', 'Sandra')]}]