Proof (2001), a play by David Auburn, won the Pulitzer Prize in 2001, as well as several other major awards for drama. The play is set in Chicago, where Robert, a former genius of a mathematician who suffered from mental illness, has recently died. Robert appears in the play talking with his daughter Catherine, a depressed college drop-out who stayed at home and cared for her father over the last few years of his life. As preparations are made for the funeral and Catherine’s sister Claire returns from New York, Catherine forms a tentative friendship with Hal, a mathematician who is one of her father’s former students.
The plot moves into high gear when Hal discovers in one of the notebooks that Robert left behind a proof of a mathematical theorem that mathematicians had thought impossible. It is a sensational discovery, but Catherine stuns Hal by claiming she wrote the proof. But did she? The handwriting in the notebook looks very like her father’s. As the mystery develops and resolves, the playwright explores issues such as what the link may be between genius and madness and whether either or both can be inherited. But Proof is also a story about human relationships, suggesting that developing trust and love can be as difficult, and just as uncertain, as establishing the truth of a mathematical proof.