Both Don Cheadle and Ayo Edebiri are making their Broadway debuts in this first Broadway revival of David Auburn’s play about a family of mathematicians — the father a genius who became mentally ill; the daughter afraid that she too is both. “Proof” remains the same appealing play – part family drama, part comedy, part mystery – that it was a quarter century ago,  when it ran for more than two years and won three Tony Awards (including Best Play) and the Pulitzer Prize for Drama.  But the casting shifts the emphasis in this production in a couple of ways, one obviously and intentionally, the other surely not.

In the first scene, Catherine (Edebiri) sits on the back porch of her family’s house in Chicago shortly after midnight and the start of her twenty-fifth birthday. Her father Robert (Cheadle) urges her to go out and celebrate. He worries about her: She sleeps late, lets the dishes pile up, does nothing productive, and in this way has lost “33 and a quarter days,” as father and daughter determine with mathematical precision. 

 By the end of the scene, we learn why she is despondent. Her father is actually dead; he died a week earlier (she’s hallucinating or more likely imagining or dreaming this conversation.) Catherine, a promising student, had dropped out to spend the last few years taking care of him. 

Her father disappears, and Hal arrives on the porch, for real.  Her father’s former graduate student, Harold Dobbs (Jin Ha) has been rummaging around upstairs looking through her father’s many notebooks, searching for more of the original mathematical discoveries that Robert made in his youth.

“There’s nothing up there,” Catherine says. “It’s garbage.” His father started losing his mind shortly after he made his greatest discoveries in his early twenties (younger than Catherine is now.) For the last three decades of his life, Robert wrote in notebooks, but it’s all “gibberish.”

Still, Hal insists, “someone should read them.”

At the end of Act I, his insistence has paid off. Hal is ecstatic to have discovered a notebook full of a startling mathematical proof, one that proves a theorem “that mathematicians have been trying to demonstrate since there were mathematicians basically!”  Catherine tells him: It isn’t Robert’s work; it’s hers.

“Proof” asks us to contemplate many things, such as the sacrifices of caretaking, the uncertainty of life in your twenties, the burden of genius. It also asks us to consider the beauty of mathematics, and the humanity of mathematicians. As David Bayer, professor of mathematics, wrote in the Journal of the American Mathematical Society about the original production: “It is a rare treat to see the romance of a mathematical proof take center stage in a popular work that teases with our preconceptions without succumbing to stereotype.”

The professor means the stereotype that the general public holds about mathematicians, but playwright David Auburn  also subtly plays with another stereotype. Hal doesn’t believe in Catherine’s authorship of the proof, for a number of reasons, one of which, we surmise, is her gender.  Earlier, before Hal reads the notebook with the jackpot, Catherine tells the true story of Sophie Germain, a brilliant mathematician in 18th century France who was barred from formal study because she was a woman and had to use a man’s name to write about her discoveries with the leading mathematicians of the day.

It’s a passage easily missed in the original, but the new production of “Proof” puts more of an emphasis on such outsider struggles for recognition in its casting of all three mathematician characters – Catherine and Robert with Black actors, Hal with the Korean-born Jin Ha. No lines are changed; there is no need to do so to make the point.

An odd feature of the set is that the old-fashioned back porch during scene changes is suddenly outlined in lights that travel along rectangular path — the window frames, and doorways, etc. This may be an effort to evoke modern tech (much like the design of the recent play “Data”) and thus give the production a more up-to-date feel. But it’s the casting that helps bring “Proof” genuinely up to date. Since the play’s original run, we’ve become more aware real-life pioneers, such as in the the 2016 book and movie “Hidden Figures,”  based on the true story of the accomplishments made by, and discrimination faced by, Katherine Johnson, a mathematician and two colleagues, all of them Black women, who worked for NASA. It feels worth mentioning that, if there is such a thing as a famous mathematician these days (presently alive, as opposed to, say, Pythagoras or Euclid, or Isaac Newton) it would Terence Tao, a naturalized American citizen born of Chinese immigrant parents in Australia, who is a professor at UCLA.

There is a fourth character in “Proof” – Claire, Catherine’s sister, who comes in to Chicago for their father’s funeral from her home in New York City, where she works as a Wall Street currency analyst. This is not the family business of mathematics, but also a field in which it helps to be quick with numbers, and, as Claire says, “I probably inherited about one-one thousandth of my father’s ability… Catherine got more, I’m not sure how much.”

Kara Young, the two-time Tony-winning Broadway veteran, was cast as Claire shortly before performances began, when the original cast member had to drop out because of a medical condition. Her casting has a surprising effect in a play that seems designed to revolve around Catherine. Edebiri, best known for her Emmy-winning role as sous chef Sydney Adamu on The Bear, certainly makes a respectable debut on stage. Cheadle, Oscar nominee for Hotel Rwanda, does a fine job in his role, but Robert has just a few more scenes (in flashback) after the one where he’s dead. Jin Ha, so splendid in the Broadway revival of  “M Butterfly,”  has some subtle comic moments when Hal is awkwardly caught between the family members, but his infatuation with Catherine never feels completely persuasive.

 We are prepped to view Claire as an annoyance, at best a foil – -Catherine says she doesn’t like her before we even meet her, and Claire enters the back porch, well-dressed, no-nonsense, and take-charge. An early, humorous exchange captures the dynamic:

Underneath the trivial conversation there is a two-way antagonism and differing world-view at play – Catherine lording her superior intellect (and rebelliousness), Claire her greater understanding of the practical (and bossiness.) 

It’s in part a testament to Auburn’s nuanced writing, but I think also a reflection of Young’s extraordinary talent as a stage actress, that “Proof” becomes just a little less Catherine’s story and just a little more a play about sisters.

Proof
Booth  Theater through July 19, 2026
Running time: 2 hours and 15 minutes including a 15 minute intermission
Tickets: $94 -$421
Directed by Thomas Kail
Original music by Kris Bowers, scenic design by Teresa L. Williams, costume design by Dede Ayite, lighting design by Amanda Zieve, sound design by Justin Ellington and Conor Wang, hair and wig design by Mia Neal 
Cast: Don Cheadle as Robert, Ayo Edebiri as Catherine, Jin Ha as Hal, Kara Young as Claire