anchor.diff:  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
   ;;;
   ;;; Converting PROGN.
  +;;;
  +;;; According to section 3.2.3.1 of the HyperSpec, PROGN processes
  +;;; its subforms the same way as the form itself.
   
   (defmethod convert-special
       ((head (eql 'progn)) form environment)
  +  ;; The following expression means "if this form is a top-level
  +  ;; form, then make sure that forms compiled by a recursive call
  +  ;; to CONVERT are also top-level forms".
  +  (setf *top-level-form-p* *old-top-level-form-p*)
     (cleavir-ast:make-progn-ast
      (convert-sequence (cdr form) environment)))
   
  
positive.code: ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;;
  ;;; Converting MACROLET.
  
  ;; According to section 3.2.3.1 of the HyperSpec, MACROLET processes
  ;; its subforms the same way as the form itself.
  
  (defmethod convert-special
      ((symbol (eql 'macrolet)) form env)
  
negative.code: ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;;
  ;;; Converting LOCALLY.
  ;;;
  ;;; According to section 3.2.3.1 of the HyperSpec, LOCALLY processes
  ;;; its subforms the same way as the form itself.
  
  (defmethod convert-special
      ((symbol (eql 'locally)) form env)
  