(do
  (def SMA 
    (fn [length] 
      (do
        (def history (series :float))
        (def sum 0.0)

		(fn [val] 
           (do 
             (def hist_len (len history))
             (if (>= hist_len length)
               (assign sum (- sum (history (- hist_len 1))))
               ...)

  		  (push history val)
            (assign sum (+ sum val))
            (/ sum (len history))
           )))))

  (def sma10 (SMA 10))

(sma10 1)
(sma10 2)
(sma10 3)
(sma10 4)
(sma10 5)
(sma10 6)
(sma10 7)
(sma10 8)
(sma10 9)
(sma10 10)
(sma10 11)

)