The enfant terrible of this year's theater scene, Randall Cohn, blew into town after a stint in New York and is now in Los Angeles -- and his absence is palpable. His Evaporated Milk Society's deconstruction of Hamlet, staged in a West Bottoms loft above a saloon, could have been remarkably obtuse. All the members of his young cast (most of whom had only high-school or college drama credits) alternated playing Hamlet and Gertrude --sometimes all at once -- while engaged in modern dance poses or meditating shoeless on the floor. Who knows what the shopping cart was about, but no one who saw it will forget it.