(defun test (a)
  (lambda (b))
   (= a b))
; in: DEFUN TEST
;     (= PLAYGROUND::A PLAYGROUND::B)
; 
; caught WARNING:
;   undefined variable: PLAYGROUND::B
; 
; compilation unit finished
;   Undefined variable:
;     B
;   caught 1 WARNING condition

; in: (TEST 5) 6
;     ((PLAYGROUND::TEST 5) 6)
; 
; caught ERROR:
;   illegal function call
; 
; compilation unit finished
;   caught 1 ERROR condition