Add chapter 3 part 2

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+#lang sicp
+(#%require (only racket/base print-as-expression print-mpair-curly-braces))
+(print-as-expression #f)
+(print-mpair-curly-braces #f)
+
+;; Chapter 3
+;; Modularity, Objects, and State
+
+;; 3.2
+;; The Environment Model of Evaluation
+
+(define (square x)
+  (* x x))
+
+(define (sum-of-squares x y)
+  (+ (square x) (square y)))
+
+(define (f a)
+  (sum-of-squares (+ a 1) (* a 2)))
+
+#| 3.9 |#
+
+(#%provide factorial)
+(define (factorial n)
+  (if (= n 1)
+    1
+    (* n (factorial (- n 1)))))
+
+#| global |#
+#| ------------------- |#
+#| | factorial: -> A | |#
+#| ------------------- |#
+
+#| A |#
+#| -> |# 
+#| (lambda (n) |#
+#|   (if (= n 1) |#
+#|     1 |#
+#|     (* n (factorial (- n 1))))) |#
+#| -> global |#
+
+#| E1          E2 |# 
+#| --------    -------- |#
+#| | n: 6 |    | n: 5 | |#
+#| --------    -------- |#
+#| -> global   -> global |#
+
+#| E3          E4 |# 
+#| --------    -------- |#
+#| | n: 4 |    | n: 3 | |#
+#| --------    -------- |#
+#| -> global   -> global |#
+
+#| E5          E6 |# 
+#| --------    -------- |#
+#| | n: 2 |    | n: 1 | |#
+#| --------    -------- |#
+#| -> global   -> global |#
+
+#| In each of E1 - E6: |#
+
+#| (if (= n 1) |#
+#|   1 |#
+#|   (* n (factorial (- n 1)))) |#
+
+(define (fact-iter product counter max-count)
+  (if (> counter max-count)
+    product
+    (fact-iter
+      (* counter product)
+      (+ counter 1)
+      max-count)))
+
+(#%provide factorial-)
+(define (factorial- n)
+  (fact-iter 1 1 n))
+
+#| global |#
+#| -------------------- |#
+#| | fact-iter: -> A  | |#
+#| | factorial-: -> B | |#
+#| -------------------- |#
+
+#| A |#
+#| -> |# 
+#| (lambda (product counter max-count) |#
+#|   (if (> counter max-count) |#
+#|     product |#
+#|     (fact-iter |#
+#|       (* counter product) |#
+#|       (+ counter 1) |#
+#|       max-count))) |#
+#| -> global |#
+
+#| B |#
+#| -> |# 
+#| (lambda (n) (fact-iter 1 1 n)) |#
+#| -> global |#
+
+#| E1 |#
+#| -------- |#
+#| | n: 6 | |#
+#| -------- |#
+#| -> global |#
+
+#| In E1: |#
+
+#| (fact-iter 1 1 n) |#
+
+#| E2                 E3 |#
+#| ----------------   ---------------- |#
+#| | product: 1   |   | product: 1   | |#
+#| | counter: 1   |   | counter: 2   | |#
+#| | max-count: 6 |   | max-count: 6 | |#
+#| ----------------   ---------------- |#
+#| -> global          -> global |#
+
+#| E4                 E5 |#
+#| ----------------   ---------------- |#
+#| | product: 2   |   | product: 6   | |#
+#| | counter: 3   |   | counter: 4   | |#
+#| | max-count: 6 |   | max-count: 6 | |#
+#| ----------------   ---------------- |#
+#| -> global          -> global |#
+
+#| E6                 E7 |#
+#| ----------------   ---------------- |#
+#| | product: 24  |   | product: 120 | |#
+#| | counter: 5   |   | counter: 6   | |#
+#| | max-count: 6 |   | max-count: 6 | |#
+#| ----------------   ---------------- |#
+#| -> global          -> global |#
+
+#| E8 |#
+#| ---------------- |#
+#| | product: 720 | |#
+#| | counter: 7   | |#
+#| | max-count: 6 | |#
+#| ---------------- |#
+#| -> global |#
+
+#| In each of E2 - E8: |#
+
+#| (if (> counter max-count) |#
+#|   product |#
+#|   (fact-iter |#
+#|     (* counter product) |#
+#|     (+ counter 1) |#
+#|     max-count)) |#
+
+(#%provide make-withdraw)
+(define (make-withdraw balance)
+  (lambda (amount)
+    (if (>= balance amount)
+      (begin
+        (set! balance (- balance amount))
+        balance)
+      "Insufficient funds")))
+
+#| 3.10 |#
+
+(#%provide make-withdraw-)
+(define (make-withdraw- initial-amount)
+  (let ((balance initial-amount))
+    (lambda (amount)
+      (if (>= balance amount)
+        (begin
+          (set! balance (- balance amount))
+          balance)
+        "Insufficient funds"))))
+
+#| global |#
+#| ------------------------- |#
+#| | make-withdraw-: -> A  | |#
+#| | W1: -> B              | |#
+#| | W2: -> C              | |#
+#| ------------------------- |#
+
+#| (define W1 (make-withdraw- 100)) |#
+#| (W1 50) |#
+#| (define W2 (make-withdraw- 100)) |#
+
+#| A |#
+#| -> |# 
+#| (lambda (initial-amount) |#
+#|   (let ((balance initial-amount))) |#
+#|   (lambda (amount) |#
+#|     (if (>= balance amount) |#
+#|       (begin |#
+#|         (set! balance (- balance amount)) |#
+#|         balance) |#
+#|       "Insufficient funds"))) |#
+#| -> global |#
+
+#| E1 |#
+#| ----------------------- |#
+#| | initial-amount: 100 | |#
+#| ----------------------- |#
+#| -> global |#
+
+#| ((lambda (balance) |#
+#|   (lambda (amount) |#
+#|     (if (>= balance amount) |#
+#|       (begin |#
+#|         (set! balance (- balance amount)) |#
+#|         balance) |#
+#|       "Insufficient funds"))) initial-amount) |#
+
+#| E2 |#
+#| ---------------- |#
+#| | balance: 50  | |#
+#| ---------------- |#
+#| -> E1 |#
+
+#| (lambda (amount) |#
+#|   (if (>= balance amount) |#
+#|     (begin |#
+#|       (set! balance (- balance amount)) |#
+#|       balance) |#
+#|     "Insufficient funds")) |#
+
+#| B |#
+#| -> |# 
+#| (lambda (amount) |#
+#|   (if (>= balance amount) |#
+#|     (begin |#
+#|       (set! balance (- balance amount)) |#
+#|       balance) |#
+#|     "Insufficient funds")) |#
+#| -> E2 |#
+
+#| E3 |#
+#| ---------------- |#
+#| | amount: 50   | |#
+#| ---------------- |#
+#| -> E2 |#
+
+#| (if (>= balance amount) |#
+#|   (begin |#
+#|     (set! balance (- balance amount)) |#
+#|     balance) |#
+#|   "Insufficient funds") |#
+
+#| (begin |#
+#|   (set! balance 50) |#
+#|   balance) |#
+
+#| E4 |#
+#| ----------------------- |#
+#| | initial-amount: 100 | |#
+#| ----------------------- |#
+#| -> global |#
+
+#| ((lambda (balance) |#
+#|   (lambda (amount) |#
+#|     (if (>= balance amount) |#
+#|       (begin |#
+#|         (set! balance (- balance amount)) |#
+#|         balance) |#
+#|       "Insufficient funds"))) initial-amount) |#
+
+#| E5 |#
+#| ---------------- |#
+#| | balance: 100  | |#
+#| ---------------- |#
+#| -> E4 |#
+
+#| (lambda (amount) |#
+#|   (if (>= balance amount) |#
+#|     (begin |#
+#|       (set! balance (- balance amount)) |#
+#|       balance) |#
+#|     "Insufficient funds")) |#
+
+#| C |#
+#| -> |# 
+#| (lambda (amount) |#
+#|   (if (>= balance amount) |#
+#|     (begin |#
+#|       (set! balance (- balance amount)) |#
+#|       balance) |#
+#|     "Insufficient funds")) |#
+#| -> E5 |#
+
+#| 3.11 |#
+
+(#%provide make-account)
+(define (make-account balance)
+  (define (withdraw amount)
+    (if (>= balance amount)
+      (begin
+        (set! balance (- balance amount))
+        balance)
+      "Insufficient funds"))
+  (define (deposit amount)
+    (set! balance (+ balance amount))
+    balance)
+  (define (dispatch m)
+    (cond
+      ((eq? m 'withdraw) withdraw)
+      ((eq? m 'deposit) deposit)
+      (else
+        (error
+          "Unknown request -- MAKE-ACCOUNT"
+          m))))
+  dispatch)
+
+#| global |#
+#| ---------------------- |#
+#| | make-account: -> A | |#
+#| | acc:          -> D | |#
+#| | acc2:         -> G | |#
+#| ---------------------- |#
+
+#| (define acc (make-account 50)) |#
+#| ((acc 'deposit) 40) |#
+#| ((acc 'withdraw) 60) |#
+#| (define acc2 (make-account 100)) |#
+
+#| A |#
+#| -> |#
+#| (lambda (balance) |#
+#|   (define (withdraw amount) |#
+#|     (if (>= balance amount) |#
+#|       (begin |#
+#|         (set! balance (- balance amount)) |#
+#|         balance) |#
+#|       "Insufficient funds")) |#
+#|   (define (deposit amount) |#
+#|     (set! balance (+ balance amount)) |#
+#|     balance) |#
+#|   (define (dispatch m) |#
+#|     (cond |#
+#|       ((eq? m 'withdraw) withdraw) |#
+#|       ((eq? m 'deposit) deposit) |#
+#|       (else |#
+#|         (error |#
+#|           "Unknown request -- MAKE-ACCOUNT" |#
+#|           m)))) |#
+#|   dispatch) |#
+#| -> global |#
+
+#| E1 |#
+#| ------------------ |#
+#| | balance: 30    | |#
+#| | withdraw: -> B | |#
+#| | deposit: -> C  | |#
+#| | dispatch: -> D | |#
+#| ------------------ |#
+#| -> global |#
+
+#| B |#
+#| -> |#
+#| (lambda (amount) |#
+#|   (if (>= balance amount) |#
+#|     (begin |#
+#|       (set! balance (- balance amount)) |#
+#|       balance) |#
+#|     "Insufficient funds")) |#
+#| -> E1 |#
+
+#| C |#
+#| -> |#
+#| (lambda (amount) |#
+#|   (set! balance (+ balance amount)) |#
+#|   balance) |#
+#| -> E1 |#
+
+#| D |#
+#| -> |#
+#| (lambda (m) |#
+#|   (cond |#
+#|     ((eq? m 'withdraw) withdraw) |#
+#|     ((eq? m 'deposit) deposit) |#
+#|     (else |#
+#|       (error |#
+#|         "Unknown request -- MAKE-ACCOUNT" |#
+#|         m)))) |#
+#| -> E1 |#
+
+#| E2 |#
+#| --------------- |#
+#| | m: 'deposit | |#
+#| --------------- |#
+#| -> E1 |#
+
+#| (cond |#
+#|   ((eq? m 'withdraw) withdraw) |#
+#|   ((eq? m 'deposit) deposit) |#
+#|   (else |#
+#|     (error |#
+#|       "Unknown request -- MAKE-ACCOUNT" |#
+#|       m))) |#
+
+#| E3 |#
+#| --------------- |#
+#| | amount: 40  | |#
+#| --------------- |#
+#| -> E1 |#
+
+#| (set! balance (+ balance amount)) |#
+#| balance |#
+
+#| (set! balance (+ 50 40)) |#
+#| balance |#
+
+#| (set! balance 90) |#
+#| balance |#
+
+#| E4 |#
+#| ---------------- |#
+#| | m: 'withdraw | |#
+#| ---------------- |#
+#| -> E1 |#
+
+#| (cond |#
+#|   ((eq? m 'withdraw) withdraw) |#
+#|   ((eq? m 'deposit) deposit) |#
+#|   (else |#
+#|     (error |#
+#|       "Unknown request -- MAKE-ACCOUNT" |#
+#|       m))) |#
+
+#| E5 |#
+#| --------------- |#
+#| | amount: 60  | |#
+#| --------------- |#
+#| -> E1 |#
+
+#| (if (>= balance amount) |#
+#|   (begin |#
+#|     (set! balance (- balance amount)) |#
+#|     balance) |#
+#|   "Insufficient funds") |#
+
+#| (if (>= 90 60) |#
+#|   (begin |#
+#|     (set! balance (- 90 60)) |#
+#|     balance) |#
+#|   "Insufficient funds") |#
+
+#| (begin |#
+#|   (set! balance 30) |#
+#|   balance) |#
+
+#| E6 |#
+#| ------------------ |#
+#| | balance: 100   | |#
+#| | withdraw: -> E | |#
+#| | deposit: -> F  | |#
+#| | dispatch: -> G | |#
+#| ------------------ |#
+#| -> global |#
+
+#| E |#
+#| -> |#
+#| (lambda (amount) |#
+#|   (if (>= balance amount) |#
+#|     (begin |#
+#|       (set! balance (- balance amount)) |#
+#|       balance) |#
+#|     "Insufficient funds")) |#
+#| -> E6 |#
+
+#| F |#
+#| -> |#
+#| (lambda (amount) |#
+#|   (set! balance (+ balance amount)) |#
+#|   balance) |#
+#| -> E6 |#
+
+#| G |#
+#| -> |#
+#| (lambda (m) |#
+#|   (cond |#
+#|     ((eq? m 'withdraw) withdraw) |#
+#|     ((eq? m 'deposit) deposit) |#
+#|     (else |#
+#|       (error |#
+#|         "Unknown request -- MAKE-ACCOUNT" |#
+#|         m)))) |#
+#| -> E6 |#