Theatregoers hoping to catch the smash Tony Award and Pulitzer Prize winner, Proof, Dec. 3 were sent into the cold about 8:30 PM when "technical difficulties" led to a canceled performance.

Refunds and exchanges were made available for that performance; the run resumes Dec. 4. The technical issue, it turns out, was that star Len Cariou was detained out of town on a film shoot and his understudy, Ron Parady, could not be reached in time to cover the performance, a spokesman said. Parady goes on Wednesday for Cariou.

Such things rarely happen in the Broadway arena, where understudies are usually kept within the theatre or within blocks of a theatre until the "half-hour" call. Many actors these days, if they are within a cab or subway ride, will call and check in with their stage manager; some are kept on beeper.

The Cariou role in David Auburn's Proof is not incidental — he plays the brilliant but mentally ill father of the lead character, Catherine, who herself is showing signs of both illness and genius. The cast of four includes Anne Heche (as Catherine), Kate Jennings Grant as sister Claire and Stephen Kunken as Catherine's suitor, Hal.

The hit production ends Jan. 5, 2003, leaving room at the Walter Kerr Theatre for Richard Greenberg's Take Me Out.