(defun str-rest (str)
   (coerce (rest (coerce str 'list)) 'string))

(defun rdc (xs)
   (if (endp (rest xs))
       nil
       (cons (first xs)
             (rdc (rest xs)))))

(defun str-rdc (str)
   (coerce (rdc (coerce str 'list)) 'string))

(str-rdc "string")
(str-rest "string")
(str-rest (str-rdc "string"))