Proof is a play by David Auburn which won the 2001 Pulitzer Prize for Drama and the 2001 Tony Award for Best Play.
It concerns the daughter of a recently-deceased professor of mathematics at the University of Chicago and her struggle with mathematical genius and mental illness. The daughter had cared for her father through a lengthy mental illness; upon his death, a paradigm-shifting proof was found in his office. The title refers both to that proof and to the play's central question: Can the daughter prove the proof's authorship? Along with proving the proof, the daughter also finds herself in a relationship with an ex-student of her father, 28 year old Hal.
Proof is being adapted as a movie, to be released in 2005, directed by John Madden and starring Gwyneth Paltrow Anthony Hopkins Hope Davis and Jake Gyllenhaal.