Proof is a play by David Auburn. It won the 2001 Pulitzer Prize for Drama and the 2001 Tony Award for Best Play.
The play concerns Catherine, the daughter of Robert, a recently deceased mathematical genius and professor at the University of Chicago, and her struggle with mathematical genius and mental illness. Catherine had cared for her father through a lengthy mental illness. Upon Robert's death, his ex-graduate student Hal discovers a paradigm-shifting proof about prime numbers in Robert's office. The title refers both to that proof and to the play's central question: Can Catherine prove the proof's authorship? Along with proving the proof, the daughter also finds herself in a relationship with 26-year-old Hal. Throughout, the play explores Catherine's fear of following in her father's footsteps, both mathematically and mentally.
Proof was originally produced by the Manhattan Theatre Club on May 23, 2000. It then went to Broadway on October 24, 2000. Directed by Daniel Sullivan, with Mary-Louise Parker as Catherine, Larry Bryggman as Robert, Ben Shenkman as Hal, and Johanna Day as Claire. Mary-Louise Parker won the Tony Award for her performance. Later during the Broadway run, Anne Heche would take over the lead.
It subsequently was staged at the Donmar Warehouse in London's West End. Gwyneth Paltrow starred as Catherine, with direction by John Madden, whom she had worked with on Shakespeare In Love. This production also featured Richard Coyle, Ronald Pickup and Sara Stewart. Paltrow reprised the role in the 2005 film Proof, which was directed by John Madden again. Along with Paltrow, it starred Anthony Hopkins, Hope Davis, and Jake Gyllenhaal. The film version added more characters, whereas the play had only four characters.