40 Fun Facts About Proof (David Auburn Play)

Which award, overseen by Columbia University, did Proof win in 2001 alongside the Tony for Best Play?

The Pulitzer Prize for Drama helped make Proof a fixture: by 2002 it was the most widely produced play in the United States.

Which Oscar-winning actress played Catherine in Proof on the London stage and again in the 2005 film?

Gwyneth Paltrow took the part on stage in London in 2002 before filming it, and the screen version earned her a Golden Globe nomination for Best Actress in a drama.

Which Welsh actor played Robert, the brilliant but troubled mathematician, in the 2005 film of Proof?

Anthony Hopkins played Robert, a character the stage version shows only in flashbacks and in Catherine's imagination.

Which star of The Bear played Catherine when Proof returned to Broadway in 2026 for its first revival?

Ayo Edebiri made her Broadway debut in the part, and the revival's final week in July 2026 sold out completely.

Robert's early game-theory work and later breakdown in Proof echo which subject of A Beautiful Mind?

John Nash wrote a 27-page thesis on game theory at 21 and began behaving irrationally at 30, an arc critics see mirrored in Robert.

What does Robert produce in the opening scene of Proof to mark Catherine turning 25?

A bottle of champagne is Robert's gift, yet the cosy scene is only in her head: Robert died the week before.

Which instrument does Hal play in a rock band made up entirely of fellow mathematicians in Proof?

Drums are Hal's instrument, and the band turns up to play at the party held on the night of Robert's funeral.

Hal's band in Proof has a song named after the imaginary number i; how do the musicians perform it?

Standing in silence for three minutes is the whole act, a maths joke Hal tells Catherine while inviting her to come and hear the band.

Before his remission in Proof, where did Robert believe extraterrestrials were hiding coded messages for him?

Library books carried the code, Robert believed: he borrowed them in bulk, convinced aliens were sending messages through their Dewey decimal numbers.

Which actor played Hal in the 2005 film of Proof, released the same year as his Brokeback Mountain?

Jake Gyllenhaal played Hal, who in the film chases the sisters' departing car and throws the notebook through its window.

The revolutionary result that Hal reads in one of the notebooks in Proof is a theorem about what?

Prime numbers are the subject, though the theorem is never spelled out; David Auburn said the maths was just the glue holding a family drama together.

At what point in Proof does Catherine stun Hal and Claire by saying the notebook's mathematics is hers?

The end of Act One brings the announcement, and audiences regularly gasped as the interval curtain came down on it.

Before he turns up to sort through the notebooks in Proof, what was Hal to Robert?

His former student: Robert steered Hal through a rough patch in his doctorate, and Hal now combs the notebooks hoping to find something publishable.

To which city does Claire press Catherine to move with her once Robert's funeral is over in Proof?

New York is where Claire has built her life, and in the final scene she leaves Catherine's plane ticket behind as she storms off.

What does a hungover Claire reveal she intends to do with the family home in Proof?

Sell it, she says, and the news sets off the sisters' fiercest row, with Catherine accusing Claire of leaving her to nurse Robert alone.

Whom does Catherine telephone on catching Hal sneaking a notebook out of the house in Proof?

The police are dialled mid-argument, and officers call at the house next morning, which is how Claire comes to hear of the row.

Catherine searches Hal's backpack in Proof and finds nothing; where was the notebook actually hidden?

In his jacket, and when it slips out it proves to hold a lucid entry that Robert wrote about Catherine four years earlier.

What reason does Hal give Catherine for smuggling one particular notebook out of the house in Proof?

As a birthday present, he says: he meant to wrap it for her, because in it Robert thanks Catherine for looking after him.

Catherine hands Hal a key the morning after they spend the night together in Proof; what does it open?

A desk drawer of Robert's holds the crucial notebook, and handing over the key is Catherine's way of showing Hal that she trusts him.

At which university, where David Auburn himself studied, was Robert a celebrated professor in Proof?

University of Chicago life gave David Auburn his setting, and he recalled the Broadway set drawing gasps from people who had lived in the neighbourhood.

At which university near her home did Catherine briefly study maths before dropping out in Proof?

Northwestern was only a short drive away, as Catherine promised Robert, yet she left within months when his delusions returned.

Which mathematician, who wrote to Gauss under a man's name, does Catherine hold up to Hal in Proof?

Sophie Germain signed herself Monsieur Le Blanc, and Catherine quotes to Hal the admiring letter Gauss sent on learning the truth.

On which part of the family's row house does every scene of David Auburn's Proof take place?

The back porch is the only setting, and David Auburn has called his play a conventional back-porch drama that happens to be set on a campus.

What news of her own does Claire announce to Catherine over brunch in Proof?

She is getting married, in January, and she uses the news to press Catherine to come and stay with her well before then.

In what well-paid job has Claire, Catherine's practical older sister, made her career in Proof?

Currency analyst is Claire's job, and she says her fourteen-hour days paid off the mortgage on the house where Catherine nursed Robert.

When a jubilant Robert makes Catherine read his new work aloud in Proof, what does the notebook contain?

Rambling nonsense about winter, bookstores and the cold fills the page, and Catherine sees at once that his mind is slipping again.

What finally persuades Hal that Catherine, not Robert, produced the mathematics he had checked in Proof?

Its newer techniques came along too late for Robert to have known them, yet Catherine retorts that this proves nothing and he should have trusted her.

Which feature of the crucial notebook in Proof makes Claire and Hal doubt that Catherine filled it?

The handwriting looks just like Robert's, and Hal points out that nothing Catherine could explain aloud would settle whose it was.

What is Catherine doing as the lights fade on the final scene of David Auburn's Proof?

Talking Hal through her work is the closing image: she opens the notebook, finds a passage, looks at him and simply begins to speak.

Which company gave Proof its world premiere in May 2000 before the production moved to Broadway?

Manhattan Theatre Club gave the play a three-month run that sold out, and the director and the whole cast then moved with it to Broadway.

Which Broadway theatre housed the original production of Proof for 917 performances, until January 2003?

The Walter Kerr kept the play running for more than two years; the 2026 revival chose a different house, the Booth.

Which actress won a Tony for creating the role of Catherine in Proof, first off Broadway and then on it?

Mary-Louise Parker won Best Actress in a Play for the part, and later took the same Tony a second time for The Sound Inside.

Which director won a Tony for staging the original Proof and later directed David Auburn's The Columnist?

Daniel Sullivan stayed with the play from its Off-Broadway opening, and David Auburn called him probably the best director in America.

Which sitcom star, later a four-time host of the Tony Awards, made his Broadway debut playing Hal in Proof?

Neil Patrick Harris joined as a replacement in 2002, between his years as a teenage TV doctor and his run in How I Met Your Mother.

At which small Covent Garden theatre did Proof have its London premiere in May 2002?

Donmar Warehouse once served as a banana-ripening depot for the nearby market, long before it became a 251-seat studio theatre.

Which director of Shakespeare in Love staged Proof in London and then made the 2005 film version?

John Madden kept his London leading lady for the screen and filmed on a real campus, though its Divinity School stood in for the maths building.

Which filmmaker, daughter of the author of Death of a Salesman, co-wrote the 2005 film of Proof?

Rebecca Miller shares the screenplay credit with David Auburn, and the film adds minor characters to a story told on stage by just four.

Whose memoir A Mathematician's Apology was David Auburn reading in London when he devised Proof?

G. H. Hardy wrote that the best proofs join unexpectedness with inevitability, which struck David Auburn as an equally good rule for drama.

Which time-crossed romance starring Sandra Bullock and Keanu Reeves did David Auburn script after Proof?

The Lake House followed in 2006, and a year later David Auburn directed his own script for The Girl in the Park.

Which Oscar-nominated film actor made his Broadway debut as Robert in the 2026 revival of Proof?

Don Cheadle, nominated for Hotel Rwanda, played Robert in the play's first Broadway revival, which opened at the Booth in April 2026.