Specifically, it concerns the discovery in the professor's South Side home of a mathematical theorem about prime numbers. If true, the consequences could be historic, according to Hal, one of the professor's former grad students and now an instructor at the university. It contains two secondary characters who add spice and tension. Catherine battles her older sister Claire, a Wall Street executive who returns to Chicago for the father's funeral. Claire is the drama's nominal villain, but as played by Johanna Day, she exhibits an understandable common sense as she tries to sort out her sister's messy life.
Proof is also a love story, one the playwright handles in a fresh and funny way.
Their courtship, as well as Catherine's confrontations with her sister and her dealings with Dad, take place on designer John Lee Beatty's cozy back porch, a suitable arena for dealing with family affairs. The Beacon Journal Publishing Co.