“Proof,” an award-winning drama by David Auburn, is the latest offering at Goshen’s New World Arts and proves (no pun intended) that some of the best things, theatrically speaking, come in small packages.

With a cast of four and one basic set, the story of  Catherine (Emily Shenk), her father Robert (Darryl Gillikin), her sister Claire (Libby Unruh) and Hal (Aaron Schwinn) makes for a fascinating evening. The title refers to several kinds of proof, all of which are important to Catherine, who  literally is fighting for her sanity and her independence.

Robert (Darryl Gilliken) and daughter Catherine (Emily Shenk) have a heated discussion in this scene from the New World Arts production of "Proof."

At her home near the University of Chicago, she celebrates her 25th birthday awaiting her older sister’s arrival from New York for the funeral of their father, in his 20s a ground-breaking mathematician who fought dementia in his later years. Following in his academic footsteps, and afraid she is following his mental descent, Catherine left school to care for Robert during the final five years of his life when, excepting one nine month period, reality and all semblance of rational thought slipped quickly away.

With Claire’s authoritative arrival comes the announcement that she plans to sell the family home and wants her sister to return with her to New York where she and her fiance can take care of her. As Catherine faces this challenge, Hal, her father’s former graduate student now a teacher himself, arrives to search the mathematician’s notebooks in search of anything of importance. After going through more than 100 books of “gibberish,” he finds a different sort of equation with Catherine.  This immediately precedes his discovery of one notebook that contains “historic proof”of a theory about prime numbers.

A shocking relevation by Catherine leads to the final determination of  her ability to care for herself and for her father’s legacy.

Claire (Libby Unruh) and Hal (Aaron Schwinn) debate the authorship of a newly discovered mathematical theorum in "Proof."

The NWA is fortunate to have found Shenk, a Bethany Christian High School senior, for the major role. She delivers a strong performance, delivering the many facets of the conflicted young woman honestly and believeably, no small accomplishment, especially in a teenager. Her fellow players make up a very solid and intelligent ensemble, especially Gillikin who, it becomes apparent, is a spirited character.

The setting, the porch of the family home in a Chicago suburb, is minimal and doesn’t add much to the essence of the play. The lighting is adequate, although too deliberately dim for the opening scene. There is, however, one very annoying aspect. The screen door screeches at every exit and entrance, whether part of the action or during a scene change. If it was meant to support  the delapidated condition of the house, that was accomplished by the torn screen. The noise become increasingly mood-shattering and was not fair to the work being done by the actors. I would have been glad to provide an oil can.

“PROOF” plays at 8 p.m. Friday and Saturday and July 23-24 in  the theater  on Main Street in Goshen. Entrance from Third Street. Tickets at the box office or call(800) 838-3006.