1 ;; The first three lines of this file were inserted by DrScheme. They record metadata
2 ;; about the language level of this file in a form that our tools can easily process.
3 #reader(lib "htdp-intermediate-reader.ss" "lang")((modname 18.1.1) (read-case-sensitive #t) (teachpacks ((lib "draw.ss" "teachpack" "htdp") (lib "arrow.ss" "teachpack" "htdp") (lib "dir.ss" "teachpack" "htdp") (lib "hangman.ss" "teachpack" "htdp"))) (htdp-settings #(#t constructor repeating-decimal #f #t none #f ((lib "draw.ss" "teachpack" "htdp") (lib "arrow.ss" "teachpack" "htdp") (lib "dir.ss" "teachpack" "htdp") (lib "hangman.ss" "teachpack" "htdp")))))
4 (local (
5         (define x (* y 3))
6         )
7        
8   (* x x))
9 
10 (local (
11         
12         (define (odd an)
13 	       (cond
14 		 [(zero? an) false]
15 		 [else (even (sub1 an))]))
16         
17         
18         (define (even an)
19           (cond
20             [(zero? an) true]
21             [else (odd (sub1 an))])))
22   
23   
24   (even a-nat-num))
25 
26 (local (
27         
28         (define (f x) (g x (+ x 1)))
29         (define (g x y) (f (+ x y)))
30         
31         )
32        
33   
34   (+ (f 10) (g 10 20))
35   
36   )
37 
38 (local (
39         (define x 10)
40 	     (y (+ x x)))
41        y)
42 
43 (local (
44         
45         (define (f x) (+ (* x x) (* 3 x) 15))
46         (define x 100)
47         (define f@100 (f x))
48         
49         )
50        
51   
52   f@100 x)
53 
54 (local (
55         (define (f x) (+ (* x x) (* 3 x) 14))
56         (define x 100)
57         (define f (f x)))
58        f)
59 
60 1. (define A-CONSTANT
61        (not 
62 	 
63         
64         (local (
65                 
66                 (define (odd an)
67                   (cond
68                     [(= an 0) false]
69                     [else (even (- an 1))]))
70                 
71                 
72                 (define (even an)
73                   (cond
74                     [(= an 0) true]
75                     [else (odd (- an 1))]))
76                 
77                 )
78           
79           
80           (even a-nat-num)
81           
82           )
83         
84         ))
85 2. (+
86      
87     
88     (local (
89             
90             
91             
92             (define (f x) (+ (* x x) (* 3 x) 15))
93             (define x 100)
94             (define f@100 (f x))
95             
96             
97             
98             )
99 	  f@100)
100     
101     
102     
103 	1000)
104 3. (local (
105            
106            
107            (define CONST 100)
108            (define f x (+ x CONST))
109            
110            
111            
112            )
113        
114      
115      (define (g x y z) (f (+ x (* y z))))
116      
117      
118      )
119 
120 
121 = (define (D x y)
122     (local ((define x2 (* x x))
123 	    (define y2 (* y y)))
124       (sqrt (+ x2 y2))))
125   (+ (local ((define x2 (* 0 0))
126 	     (define y2 (* 1 1)))
127        (sqrt (+ x2 y2)))
128      (D 3 4))
129   
130 ;; sort : list-of-numbers  ->  list-of-numbers
131 (define (sort alon)
132   (local (
133           
134           (define (sort alon)
135             (cond
136               [(empty? alon) empty]
137               [(cons? alon) (insert (first alon)
138                                     (sort (rest alon)))]))
139           
140           
141           (define (insert an alon)
142             (cond
143               [(empty? alon) (list an)]
144               [else (cond
145                       [(> an (first alon)) (cons an alon)]
146                       [else (cons (first alon) 
147                                   (insert an (rest alon)))])]))
148           
149           )
150     (sort alon)))