Reviewed by Judy Richter
Presented by Hillbarn Theatre, "Proof" takes place in a Chicago backyard in September. Robert (Steve Lambert), the father of 25-year-old Catherine (Ali Marie Gangi), died five days earlier. She had been taking care of the once-brilliant mathematician and University of Chicago professor because he was mentally ill for the past five years.
It's the day before his funeral. She has allowed Hal (Brad Satterwhite), Robert's former doctoral student, now a math professor, to go through his hundreds of notebooks in case they hold something important rather than gibberish.
They are joined by Claire (Cynthia Lagodzinski), Catherine's older sister, a currency analyst in New York.
As Catherine and Hal become attracted to each other, she allows him to see one more notebook. It contains what Hal believes to be a profoundly important, even revolutionary mathematical proof.
Catherine has had relatively little formal mathematical training (she dropped out of Northwestern to care for Robert). Therefore, Hal challenges her to prove her contention that she developed it. There's also an implication of sexism -- that a woman couldn't have accomplished such a feat.
Because Catherine has suffered from bouts of depression, she fears she might have inherited Robert's mental illness. Claire is worried about her, too, for she urges Catherine to join her in New York.
"Proof" won both the 2001 Pulitzer Prize for drama and the Tony Award for best play after its premiere in 2000. Auburn has created an absorbing plot and intriguing relationships between his characters.
Hillbarn director Greg Fritsch has hit the mark with three of his actors, but he has allowed Gangi too many shrill, over-the-top moments when Catherine becomes angry, which is fairly often.
Satterwhite's Hal and Lambert's Robert (seen in flashbacks) provide needed moments of calm to offset her. Lagodzinski's Claire is both controlling and condescending, two hallmarks of the character.
Because the play opened on March 13, the eve of Pi Day on March 14, or 3.14.15, the refreshment stand featured pie. The number pi, 3.1415 to infinity, has major significance in math because a circle's circumference is slightly more than three times longer than its diameter.
Steve Nyberg's homey backyard set features the Greek letter pi spotlighted overhead (lighting by David Gotlieb). The sound is by artistic director Dan Demers. Costumes are by Mae Matos. Lagodzinski does double duty as hair and makeup consultant.
This two-act well-written play runs about two hours with one intermission.