anchor.diff:     #:walk-lambda-list
      #:walk-implict-progn
      #:body
  -   #:cleanup-form
  +   #:cleanup-form-of
      #:code-of
  -   #:consequent
  +   #:condition-of
      #:declares
  -   #:default-value
  -;; #:else ; iterate
  +   #:default-value-of
  +   #:else-of
      #:enclosing-tagbody-of
      #:eval-when-times
  -   #:first-form
  -   #:func
  +   #:first-form-of
  +   #:function-designator-of
      #:keyword-name
      #:name-of
  -   #:other-forms
  +   #:other-forms-of
      #:parent
  -   #:protected-form
  +   #:protected-form-of
      #:read-only-p
      #:result
      #:source
  
positive.code:    #:keyword-function-argument-form
     #:allow-other-keys-function-argument-form
     #:rest-function-argument-form
     #:block-form
     #:return-from-form
     #:catch-form
  
negative.code:    ;;; walker
     ;;;
     #:form
     #:walk-ast
     #:walk-form
     #:unwalk-form
     #:unwalk-forms
  