ウォンツテック

そでやまのーと

今日も1問だけ解く
問題1.10

(define (A x y)
  (cond ((= y 0) 0)
        )((= x 0) (* 2 y))(
        ((= y 1) 2)
        (else (A (- x 1)
                 (A x (- y 1))))))
(A 1 10)
= (A 0 (A 1 9))
= 2(A 1 9)
= 2^9(A 1 1)
= 2^9*2
= 2^{10}

(A 2 4)
= (A 1 (A 2 3))
= (A 1 (A 1 (A 2 2)))
= (A 1 (A 1 (A 1 (A 2 1))))
= (A 1 (A 1 (A 1 2)))
= (A 1 (A 1 2^2))
= (A 1 2^{2^2})
= 2^{2^{2^2}}

(A 3 3)
= (A 2 (A 3 2))
= (A 2 (A 2 (A 3 1)))
= (A 2 (A 2 2))
= (A 2 (A 1 (A 2 1)))
= (A 2 (A 1 2))
= (A 2 (A 0 (A 1 1)))
= (A 2 (A 0 2))
= (A 2 2*2)
= (A 2 4)
= 2^{2^{2^2}}
(define (f n) (A 0 n))

(A 0 n)
= 2n ※Aの定義より

(define (g n) (A 1 n))

(A 1 n)
= (A 0 (A 1 n-1)) ※Aの定義より
= (f (A 1 n-1))
= 2(A 1 n-1)
= 2^{n-1}(A 1 1)
= 2^{n}

(define (h n) (A 2 n))

(A 2 n)
= (A 1 (A 2 n-1))
= (f (A 2 n-1))
= 2^{h(n-1)} ※h(n-1) = (h n-1)とする
= 2^{2^{.....}} ※n回2の冪乗を繰り返す
= \prod_{k=1}^{2^{n-1}}2