宿題?
(defun 5jou (x)
(let ((x2 0) (x3 0))
(setq x2 (2jou x)) ; x2 = x^2
(setq x3 (* x2 x)) ; x3 = x2*x = x^3
(* x2 x3))) ; x2 * x3 つまり x^5