(defun sample-function (y)  ;this y is regarded as special
   (declare (special y))                                
   (let ((y t))              ;this y is regarded as lexical
     (list y
           (locally (declare (special y))
             ;; this next y is regarded as special
             y))))
⇒  SAMPLE-FUNCTION
 (sample-function nil) ⇒  (T NIL) 
 (setq x '(1 2 3) y '(4 . 5)) ⇒  (4 . 5)

;;; The following declarations are not notably useful in specific.
;;; They just offer a sample of valid declaration syntax using LOCALLY.
 (locally (declare (inline floor) (notinline car cdr))
          (declare (optimize space))
    (floor (car x) (cdr y))) ⇒  0, 1

;;; This example shows a definition of a function that has a particular set
;;; of OPTIMIZE settings made locally to that definition.
 (locally (declare (optimize (safety 3) (space 3) (speed 0)))
   (defun frob (w x y &optional (z (foo x y)))
     (mumble x y z w)))
⇒  FROB

;;; This is like the previous example, except that the optimize settings
;;; remain in effect for subsequent definitions in the same compilation unit.
 (declaim (optimize (safety 3) (space 3) (speed 0)))
 (defun frob (w x y &optional (z (foo x y)))
   (mumble x y z w))
⇒  FROB