anchor.diff:                                       :parent labels
                                        :source (list* name arguments body))
            do (push (cons name lambda) (binds labels))
  -         do (setf env (register env :flet name lambda)))
  +         do (extend env :flet name lambda))
         (setf (binds labels) (nreverse (binds labels)))
         (loop
            for form in binds
  
positive.code:   (with-form-object (let* let*-form :parent parent :source form :binds '())
      (dolist* ((var &optional initial-value) (mapcar #'ensure-list (second form)))
        (push (cons var (walk-form initial-value let* env)) (binds let*))
        (setf env (register env :let var :dummy)))
      (setf (binds let*) (nreverse (binds let*)))
      (multiple-value-setf ((body let*) nil (declares let*)) (walk-implict-progn let* (cddr form) env :declare t))))
  
  
negative.code: 					       (loop
  						  with env = env
  						  for (name . lambda) in (binds flet)
  						  do (extend env :flet name lambda)
  						  finally (return env))
  					       :declare t)))))
  
  