You won’t need advanced calculus to see that Hillbarn Theatre’s production of David Auburn’s “Proof” adds up to a thoughtful and frequently funny evening of theater. Robert, a genius mathematician and once renowned leader in the field, fears an encroaching mental illness will keep him from any further contribution to his legacy. He takes pride and solace in daughter Catherine, who seems to have inherited some of his professional gifts. Catherine fears she has also inherited Robert’s debilitating disease.
The father-daughter relationship is lovingly played by Steve Lambert and Ali Marie Gangi.
With his silver mane and sonorous voice, Lambert is a jolly, protective and humorously intractable papa bear, but with teeth. He’s indignantly wounded when Catherine announces college plans that do not include his alma mater and delivers a roaring rebuttal when he feels cornered and managed.
Gangi convincingly radiates the glow daughters bestow on adored and perhaps idealized fathers. She willingly commits to her father’s care and also walks the delicate balance of wanting to assert her own needs. The sequence where each of them realizes that Robert’s disease, thought to be in remission, has returned is riveting and ultimately heartbreaking.
The equation is compounded by the variables of Claire, Robert’s other daughter, and Hal, a grad student with thesis-aversion issues Robert mentors during his final lucid phase.
Cynthia Lagodzinski brings a pushy efficiency to Claire, who also fears her younger sister will need long term care. She tries to mask her agenda with a breezy “what’s best for everyone” that Catherine easily sees as false. Lagodzinski plays archly brittle wit extremely well and manages to undercut her character’s self-serving nature with a dry, dispassionate pragmatism.
As an outsider negotiating the family dynamics, Brad Satterwhite’s Hal has a refreshingly honest demeanor. He brings an approachability and sincerity to the role. His Hal is willing to calmly question what he doesn’t understand – what, to his academic disposition, does not compute – even when it carries a not insignificant personal cost.
Directed by Greg Fritsch, the densely written play – a 2001 Pulitzer Prize and Tony Award winner – is well choreographed and moves at a pleasing pace, with just a bit too much reliance on shouting to create tension.
Scenic design by Steve Nyberg is nicely disbelief suspending except for a pair of awkwardly executed tree bookends. Mae Matos delivers an excellently ordinary wardrobe for the characters, notable for the numerous seamlessly executed quick changes.
Where: Hillbarn Theatre, 1285 East Hillsdale Blvd., Foster City
When: 8 p.m. Thursdays-Fridays, 2 and 8 p.m. Saturdays, 2 p.m. Sundays; closes March 29
Tickets: $23 to $42
Contact: (650) 349-6411, www.hillbarntheatre.org