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?