anchor.diff:     #:and-bind
      #:if2-bind
      #:aif2
  -;; #:while ;; iterate
  +;; #:while ; iterate
      #:awhile
  -;; #:until ;; iterate
  +;; #:until ; iterate
      #:it
      #:whichever
      #:xor
  
positive.code:    #:with-collector
     #:with-collectors
  
     #:walk-form
     #:make-walk-env
     #:*walk-handlers*
  
negative.code:    #:the-form
     #:extract-argument-names
     #:walk-lambda-list
     #:walk-implicit-progn
     #:arguments
     #:binds
     #:body
     #:cleanup-form
     #:code
     #:consequent
     #:declares
     #:default-value
  ;; #:else ; iterate
     #:enclosing-tagbody
     #:eval-when-times
     #:first-form
     #:func
     #:keyword-name
     #:name
     #:operator
     #:optimize-spec
     #:other-forms
     #:parent
     #:protected-form
     #:read-only-p
     #:result
     #:source
  ;; #:specializer ; closer-mop
     #:supplied-p-parameter
     #:tag
     #:target-block
     #:target-progn
     #:then
     #:type-form
     #:value
     #:values-form
     #:var
     #:vars-form
  
     #:defunwalker-handler
     #:unwalk-form
     #:unwalk-forms
     #:unwalk-lambda-list
  
     #:to-cps
     #:with-call/cc
  