@(define which)
@  (fun)
@(end)
@(define fun)
@  (output)
global fun!
@  (end)
@(end)
@(define caller)
@  (define fun)
@    (output)
local fun!
@    (end)
@  (end)
@  (which)
@(end)
@(caller)
@(which)