Editing Proof (play) (section)

===Act I===

The play opens with Catherine sitting in the backyard of her large, old house. Robert, her father, reveals a bottle of champagne to help celebrate her 25th birthday. Catherine complains that she hasn't done any worthwhile work in the field of [[mathematics]], at least not to the same level as her father, a well-known math genius. He reassures her that she can still do good work as long as she stops sleeping until noon and wasting time reading magazines. Catherine confesses she is worried about inheriting Robert's inclination towards mental instability. He begins to comfort her but then alludes to a "bad sign" when he points out that he did, in fact, die a week ago. Robert disappears as Catherine dozes off. She awakens when Hal, one of Robert's students, exits the house. He has been studying the hundreds of notebooks Robert left behind after his death, looking for any work that could be published. Catherine assures him that the notebooks are filled with scribbles and nonsense since her father wrote them when he was at his most delusional. Hal, attempting to flirt, invites her to go see his band later that night. Catherine becomes suspicious of him and demands to see what is in his backpack. She roots through it to find nothing but becomes infuriated when a notebook falls out of Hal's jacket. She dials the police while accusing him of trying to steal her father's work and pass it off as his own. He admits that he was sneaking it away but only to give it back to her later as a birthday present. He opens to a page that Robert wrote during a time when he was lucid. In it, Robert writes it is a "good day" and thanks to Catherine for taking care of him and expresses hope for the future. Hal leaves Catherine with the notebook. She begins to cry until she hears police sirens.

The next day Claire, Catherine's sister who just flew in from New York, is setting up brunch for them in the backyard. Catherine enters and Claire tries to goad her into idle chitchat as Catherine quietly seethes. Claire declares she is getting married and invites Catherine to stay with her and her [[fiance]] in New York. Catherine assures her she will come in January for the wedding, but Claire keeps pressing her to go earlier. When Catherine demands to know why Claire is inundating her with questions, Claire tells her the police came over earlier to check in on Catherine. Catherine admits to calling the police the previous night and tries to explain her altercation with Hal but only ends up sounding unhinged to the dubious Claire. Hal appears and asks to continue his work sorting the notebooks. Catherine lets him inside and Claire drops a hint for Catherine to try flirting with Hal by offering a bagel. Catherine storms into the house.

Later that night, after the funeral, Claire holds a party in the house for her friends as well as Hal and Robert's students. Catherine escapes to the porch where Hal finds her and offers her a beer. Hal confesses that he is not so sure about his own mathematical abilities since he considers math to be a "young man's game". Catherine tries to reassure him with a quote from [[Carl Friedrich Gauss]]. Hal responds by kissing her, much to Catherine's surprise. He apologizes for trying to steal the notebook and she apologizes for calling the police. They kiss again and Hal asks Catherine if she remembers meeting him years earlier. She says she does and recalls she thought he was "not boring". They continue to kiss.

The next morning Catherine sits outside. Hal exits the house and tells her he would like to spend the rest of the day with her. Catherine gives him a key to Robert's desk and tells him to look inside. He goes into the house. A moment later, Claire comes into the backyard, extremely hungover. Catherine, now in a good mood, tries to make nice with Claire. Claire takes the opportunity to continue to push Catherine to moving to New York. Catherine asks why she should move to New York to which Claire confesses that she is selling the house. Catherine becomes enraged at the idea and she accuses Claire of abandoning her to take care of their sick father alone. Claire insists that the reason she did so was to keep working to pay for the house as well as Catherine's education. Catherine reveals that she had to quit school to tend to Robert and then accuses Claire of trying to have her committed. Claire admits that she has researched doctors and facilities for Catherine but insists that she was not planning on having her committed. In the middle of the row, Hal appears clutching a notebook, barely containing his excitement. He tells Claire that Catherine is in possession of one of Robert's notebooks which holds a very important proof. Claire asks Catherine where she found it and Catherine tells them she didn't find it—she wrote it.