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		  2005年度「計算機ソフトウェア工学」
			   ML入門 練習問題
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通常の方法で起動した状態のocamlにおいて、次の式の値は何になるか。ただ
し、何らかのエラーになったり評価が停止しないときは×と書け。

 1.	1 + 2

 2.	1.2 +. 3.0 *. 4.0

 3.	"abc" + 3.14

 4.	let pi = 3.14 in
	2 * 5 * pi

 5.	let x = 1 in
	let x = x + x in
	x * x

 6.	let x = "1" in
	let x = 3 in
	x * x

 7.	let x = 2 * x - 3 in
	x + 7

 8.	let x =
	  let x = 1 + 2 in
	  x + 3 in
	x * 4

 9.	let x =
	  let y = 1 + 2 in
	  y + 3 in
	x * y

 10.	let x =
	  let y = 1 + 2 in
	  y + 3 in
	let y = x in
	x * y

 11.	let f x = x *. x *. 3.14 in
	f 10

 12.	let d x y = sqrt (x *. x +. y *. y) in
	d 3.0 4.0

 13.	let f x = x + x in
	let g x = x * x in
	f (g 3)

 14.	let f x = x + x in
	let f x = x * f (x - 1) in
	f 3

 15.	let f x = x * f (x - 1) in
	f 3

 16.	let rec f x = x * f (x - 1) in
	f 3

 17.	let rec f x =
	  if x = 0 then 1 else
	  x * f (x - 1) in
	f 3

 18.	let rec f x =
	  if x = 0 then 1 else
	  x * f (x - 1) in
	f (-3)

 19.	let f y = x + y in
	let x = 7 in
	f x

 20.	let x = 7 in
	let f y = x + y in
	f x

 21.	let x = 7 in
	let f y = x + y in
	let x = 3 in
	f x

 22.	let f x y = x * x + y in
	let g = f 3 in
	g 4 - g 5

 23.	let f (x, y) = x * x + y in
	let g = f 3 in
	g 4 - g 5

 24.	let f (x, y) = x * x + y in
	let g y = f (3, y) in
	g 4 - g 5

 25.	let f x y = x * x + y in
	let g y = f 3 y in
	g 4 - g 5

 26.	let f x y = x * x + y in
	let g y = f (3, y) in
	g 4 - g 5

 27.	(fun x y -> x + y * 2) 3 5

 28.	(fun (x, y) -> x + y * 2) 3 5

 29.	let f = fun x y -> x + y * 2 in
	f (3, 5)

 30.	let f g x = g (g x) in
	let h y = y * 2 in
	f h 3

 31.	let f g x = g (g x) in
	let h y = y * 2 in
	f h 3.0

 32.	let f g x = g (g x) in
	f (fun y -> y * 2) 3

 33.	(+) 1 2.3

 34.	(+.) 1.2 3.45

 35.	let f g = fun (x, y) -> g y x in
	f (-) (3, 7)

 36.	let f g = fun x y -> g y x in
	f (-) 3 7

 37.	let f g = fun x -> fun y -> g y x in
	f (-) 3 7

 38.	let f g = fun x y -> g y x in
	f (-) (3, 7)

 39.	let f = fun g x y -> g y x in
	f (-) 3 7

 40.	let f g x y = g y x in
	f (-) 3 7

以下では、あらかじめ

    type int_tree = ILeaf of int | INode of int_tree * int_tree

    type float_tree = FLeaf of float | FNode of float_tree * float_tree

    type 'a tree = Leaf of 'a | Node of 'a tree * 'a tree

と定義されていることにする。

 41.	INode(123 + 456, 789)

 42.	FNode(FLeaf 1.23, FLeaf (4.5 +. 6.7))

 43.	Node(Leaf (12 + 3), Leaf 4.5)

 44.	Node(Node(Leaf 3, Leaf 5), Leaf 7)

 45.	FLeaf(1.23, 4.5)

 46.	let t = Node(Node(Leaf 2, Leaf 3), Leaf 5) in
	match t with
	  Leaf x -> x
	| Node(y, z) -> y + z

 47.	let rec f t =
	  match t with
	    Leaf x -> x
	  | Node(l, r) -> f r ^ " " ^ f l in
	f (Node(Node(Leaf "this", Leaf "a"), Node(Leaf "is", Leaf "pen")))

 48.	let rec f t =
	  match t with
	    Leaf x -> x
	  | Node(y, z) -> y ^ z in
	f (Node(Node(Leaf "this", Leaf "a"), Node(Leaf "is", Leaf "pen")))

 49.	let rec f t =
	  match t with
	    Leaf x -> x
	  | Node(l, r) -> f r ^ " " ^ f l in
	f (Node(Node(Leaf 2, Leaf 3), Node(Leaf 5, Leaf 7)))

 50.	let rec f t =
	  match t with
	    ILeaf x -> x
	  | INode(l, r) -> f r + f l in
	f (Node(Node(Leaf 2, Leaf 3), Node(Leaf 5, Leaf 7)))