[plt-scheme] Are there different pluses?

Let's have the following module definitions:

(module pt mzscheme
  (define-syntax disp
    (syntax-rules (+)
      ((_ (+ v1 v2))
       (begin
         (display v1)
         (display "+ ")
         (display v2)))
      ((_ v) (display v))
      ))
  (provide disp))

(module dt mzscheme
  (require pt)
  (disp 1)
  (display " ")
  (disp (+ 2 3)))

The following code
(require pt)
(disp 1)
(display " ")
(disp (+ 2 3))

prints "1 5"

But (require dt) gives "1 2+ 3"

I think there are different pluses for top-level and module environments.
Is this ok?

-- 
Sergey Khorev
An it harms none, do what thou will.
 -- Wiccan Credo