P08 (**) Eliminate consecutive duplicates of list elements.

If a list contains repeated elements they should be replaced
with a single copy of the element. The order of the elements
should not be changed.
 
  Example:
  * (compress '(a a a a b c c a a d e e e e))
  (A B C A D E)

In newLisp, "apply" can be used for reduce or fold.

(define (compress lst)
  (reverse
    (apply
      (fn (accum x)
        (cond ((empty? accum) (list x))
              ((= x (first accum)) accum)
              (true (cons x accum))))
      (cons '() lst)
      2)  ;; How many things to process at a time.
))

(compress '(a a a a b c c a a d e e e e))
  ===>
(a b c a d e)