(define (remove an-i a-loi)
  (cond
    [(empty? a-loi) empty]
    [else (cond
	    [(eq? (first a-loi) an-i)
	     (remove an-i (rest a-loi))]
	    [else (cons (first a-loi)
		    (remove an-i (rest a-loi)))])]))

  (remove 0 (list 0 1 2 0 3))
= (remove 0 (list 1 2 0 3))
= (cons 1 (remove 0 (list 2 0 3)))
= (cons 1 (cons 2 (remove 0 (list 0 3))))
= (cons 1 (cons 2 (remove 0 (list 3))))
= (cons 1 (cons 2 (cons 3 (remove 0 empty))))
= (cons 1 (cons 2 (cons 3 empty)))
= (list 1 2 3)

#|
If you put this code into the definition window of DrScheme and click on
EXECUTE, you will see

  (cons 1 (cons 2 (cons 3 empty)))

six times in the evalution window. (The last line is an abbreviation).
|#