(define stack-copies-of
(lambda (quantity thing)
(if (= quantity 1)
thing
(stack (stack-copies-of (- quantity 1) thing)
thing))))
(define power
(lambda (quantity thing)
(if (= quantity 1)
thing
(* (power (- quantity 1) thing)
thing))))
Now they are truly identical except for their names and the procedures they
call.