Equivocation<br> Review By BOB VERINI
No need to equivocate: Bill Cain's "Equivocation" at the Geffen Playhouse is one of the most bracingly intelligent, sizzlingly theatrical American plays in a decade. Stuffed -- some will say overstuffed -- with themes, incidents and epigrams purporting to tell one version of William Shakespeare's midlife career crisis, it's an experience no serious theatergoer will want to miss.