(define (class-name parameters)
 (let ((super (new-part super-class-name some-parameters))
       (self 'nil))
   (let ((instance-variable init-value)
         ...)
       
     (define (method parameter-list)
       method-body)
     ...
       
     (define (dispatch message)
       (cond ((eqv? message 'selector) method)
             ...
             (else (method-lookup super message))))
       
     (set! self dispatch))
     
   self))