Proof is a 2000 play by the American playwright David Auburn. It won the 2001 Pulitzer Prize for Drama. The play concerns Catherine, the daughter of Robert, a recently deceased mathematical genius in his fifties, and her struggle with mathematical genius and mental illness. Catherine 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? Auburn writes dialogue and relationship beautifully, and we had an amazingly talented cast to pull it off.