** un-named variables
   :PROPERTIES:
   :DATE:     2011-06-27
   :END:

#+name: square
#+begin_src emacs-lisp :var it=0
  (* it it)
#+end_src

#+call: square(8)

first we can name the argument with call_square(it=4) =16=

then we can pass the argument unnamed with call_square(4) =16=

#+name: minus
#+begin_src emacs-lisp :var a=0 :var b=0
  (- a b)
#+end_src

To ensure that these arguments are passed in the correct order we can
use the following call_minus(8, 4) =-4=