anchor.diff:  					       (loop
   						  with env = env
   						  for (name . lambda) in (binds flet)
  -						  do (setf env (register env :flet name lambda))
  +						  do (extend env :flet name lambda)
   						  finally (return env))
   					       :declare t)))))
   
  
positive.code:                                      :parent labels
                                       :source (list* name arguments body))
           do (push (cons name lambda) (binds labels))
           do (setf env (register env :flet name lambda)))
        (setf (binds labels) (nreverse (binds labels)))
        (loop
           for form in binds
  
negative.code:       (loop
           for part on (body tagbody)
           if (go-tag-p (car part))
             do (extend env :tag (car part) (cdr part)))
        (loop
           for part on (body tagbody)
           if (go-tag-p (car part))
  