Who Played Hal in Proof

Hal is a role in Proof, a play that opened Broadway in 2000.

This Pulitzer Prize-winning play set in Hyde Park tells the tale of genius mathematician and University of Chicago professor Robert, who is struggling with mental illness, leaving his fiercely brilliant yet emotionally fragile daughter Catherine to pick up the pieces of her life. Caught between a new-found connection with one of Robert's former students and the reappearance of her sister, Claire, Catherine's world becomes increasingly unstable. As she struggles to find herself amid her father's world of tantalizing secrets and hidden complexities, she is forced to face the possibility of inheriting both her father's creative genius and his terrifying mental illness.