anchor.diff:  			    :value 
   			    (convert (if (typep binding-form 'symbol-form)
   					 nil
  -					 (car (subforms binding-form)))
  +					 (cadr (subforms binding-form)))
   				     environment)))))
         (loop for binding in bindings
   	    do (add-binding (name (variable binding))
  -			    (value binding)
  +			    (variable binding)
   			    (variables new-environment)))
         (make-instance 'let-form
   		     :original-form (original-form ast)
  
positive.code: 		     :body-form
  		     (convert-implicit-progn body-forms new-environment)))))
  
  ;;; At the moment, this will never be used, because the form
  ;;; has been converted to a constant already, given that constantp
  ;;; returns true for something like (quote ...)
  (defmethod convert-special ((op (eql 'quote)) ast environment)
    (assert (= (length (subforms ast)) 2))
    (make-instance 'constant-form
  
negative.code:   ;; FIXME: issue a warning if the variable doesn't exist 
    (make-instance 'setq-form
  		 :original-form (original-form ast)
  		 :variable (lookup (original-form (cadr (subforms ast)))
  				   environment
  				   'variable)
  		 :value (convert (caddr (subforms ast)) environment)))
  
  (defmethod convert-special ((op (eql 'progn)) ast environment)
    (cond ((null (cdr (subforms ast)))
  