Proof a play by David Auburn #52

Synopsis from Amazon

Adult/High School-Twenty-five-year-old Catherine, who sacrificed college to care for her mentally ill father (once a brilliant, much-admired mathematician), is left in a kind of limbo after his death. Socially awkward and a bit of a shut-in, she is gruff with Hal, a former student who shows up even before the funeral wanting to root through the countless notebooks her father kept in the years of his decline, hoping to find mathematical gold. On the heels of his arrival comes Claire, Catherine's cosmopolitan, blandly successful, and pushy sister, with plans to sell their father's house and take Catherine (whom she's convinced has inherited a touch of their father's illness) with her back to New York. Catherine does not want to leave, and things become more complicated as she and Hal tentatively begin to develop a relationship. She gives him the key to a drawer in her father's desk, where the "gold" waits-in the form of a notebook filled with the most original and astonishing mathematical proof Hal has seen in years. Thrilled, he wants to take immediate steps to have the proof published in her father's name, until Catherine shocks both him and Claire by declaring that she is its author. Hal's harsh incredulity pushes Catherine into an indifferent funk, sorely disappointed by the insult of having to prove her honesty to a friend she had trusted. There is much to appeal to YAs in this Pulitzer Prize- and Tony Award-winning play, which crackles with subtle wit while tackling large questions