Хаггарти р дискретная математика для программистов,...

400
программирования Р. ХАГГАРТИ ТЕХНОСФЕРА Москва 2012 Допущено УМО вузов РФ по образованию в области прикладной математики в качестве учебного пособия для студентов высших учебных заведений, обучающихся по направлению подготовки «Прикладная математика» Дискретная математика для программистов Издание 2−е, исправленное Перевод с английского под редакцией С.А. Кулешова с дополнениями А.А. Ковалева, В.А. Головешкина, М.В. Ульянова

description

 

Transcript of Хаггарти р дискретная математика для программистов,...

  • .

    2012

    ,

    2,

    ..

    .. ,

    .. , ..

  • 519.854 22.176 1313 .

    2-,

    : , 2012. 400 ., ISBN 978-5-94836-303-5

    , - . , , - . , , , . , - . ( ) .

    , , - .

    , , , -.

    519.854 22.176

    Pearson Education Limited 2002 This translation of DISCRETE MATHEMATICS FOR COMPUTING, First Edition is published by arrangement with Pearson Education Limited. 2012, , , ,-,

    ISBN 978-5-94836-303-5ISBN 0-201-73047-2 (.)

  • ................................................ 6

    .................................................................. 9

    1.

    ........................................................................ 11

    1.1. ............................................................ 11

    1.2. ................................................................... 14

    1 ........................................................... 19

    .................................................. 21

    2.

    ............................................. 23

    2.1. ................................................. 23

    2.2. ................................................. 27

    2.3. .................................................. 30

    2.4. ............................................. 32

    2 ........................................................... 35

    .................................................. 38

    . ................................ 39

    3.

    .......................................................... 44

    3.1. .................................... 44

    3.2. ........................................................ 51

    3.3. ...................................... 53

    3 ........................................................... 58

    .................................................. 61

    . .................................... 63

    4.

    .................................................................... 68

    4.1. .................................................... 68

    4.2. ..................................................... 73

    4.3. .......... 77

    4 ........................................................... 82

    .................................................. 85

    . .................. 86

    5.

    ........................................................................ 91

    5.1. ................ 91

    5.2. ..................................................................... 96

    5.3. ...................... 102

    5.4. ......................................................... 105

  • 4

    5 ........................................................... 108

    .................................................. 112

    . ....... 113

    6.

    . ............................................................ 117

    6.1. ...................................... 117

    6.2. .............................................. 120

    6.3. ........................................................... 128

    6 ........................................................... 131

    .................................................. 135

    . .............................. 136

    7.

    ............................................................................ 141

    7.1. .................................................. 142

    7.2. .................................................... 147

    7.3. ....................................................................... 152

    7 ........................................................... 158

    .................................................. 163

    . ......................................... 165

    8.

    ............................................ 171

    8.1. ............................................... 171

    8.2. .......................................................... 175

    8.3. ......................................................... 181

    8 ........................................................... 184

    .................................................. 187

    . .................................. 189

    9.

    ............................................................. 194

    9.1. ............................................................. 194

    9.2. ............................................................... 200

    9.3. ................................................. 205

    9 ........................................................... 208

    .................................................. 211

    . 2- ................ 212

    ................................................... 217

    .................................. 275

    .1. ......................................... 275

    .1.1. -

    ........................................................... 277

  • 5

    .1.2.

    .................................................................. 278

    .1.3.

    ............................................. 279

    .2. ................................................... 281

    .2.1. , 282

    .2.2. ............................. 286

    .3. ........................................................ 288

    .3.1. .......... 289

    .3.2. ................................................... 292

    .4. ........................................ 294

    .4.1. .......................................... 300

    ............................... 305

    ......................................................... 305

    .5. ............ 305

    .............................................................. 305

    .5.1. ....................... 306

    .5.1 ..................................................... 317

    .5.2. .................................... 318

    .5.2 ..................................................... 332

    .5.3. . -

    ................................................................ 333

    .5.3 ..................................................... 344

    .5.4. .. 345

    .5.4 ..................................................... 359

    .6.

    ........... 359

    .............................................................. 359

    .6.1. m- -

    ............................................................ 361

    .6.2. , -

    ............................. 362

    .6.3. NP- ................... 366

    .6.4. -

    ............................................ 368

    .6.5. -

    .................... 372

    .6.6. ........ 381

    .6........................................................ 392

    ................................................................... 395

    ................................................ 397

  • :

    = 15

    P P 24

    P Q P Q 25

    P Q P Q 25

    P Q P Q 27 28 28n! n 37

    {P}A {Q} - A 39a S a | S 45a 6 S a S 45{x : P (x)} x,

    P (x) 45

    46

    N 46

    Z 46

    Q 46

    R 46

    A S A | S 46A B A B 47A B A B 47A \B A B 48U 48

    A A 48

    A B A B 49

    |S| S 54(a; b) 55

    AB A B 55R2

    56

    A

    n

    n -

    A 57

    P(A) 61M(i; j) ,

    i- j- 71

    xR y (x; y) R 72

  • 7

    R

    R 75

    E

    x

    x 78

    x y x | - y 80

    87

    88

    89

    R

    1 91

    S R R S 92MN M N 94

    f(x) x 97

    f : A B A B 97f(A) f 97

    f

    1: A 102

    g f f g 104|x| x 110x x 110P (n; k) (n; k)-

    121

    C(n; k) (n; k)-

    123

    O(g(n)) , -

    , g(n)

    137

    (v) 143

    G = (V; E) V

    E 143

    (G) 146

    K

    n

    n 148

    154

    P 160

    -

    171

    M

    k

    k

    M 176

    M

    176

    d[v v 182

    p p 195

    p q p q 195p q p q 195{ { 200

  • 8

    a

    b

    a b 205

    a a 205

    a

    b

    a b 205

    { 205

    { { 209

  • | -

    , , .

    ,

    ,

    , . -

    , , ,

    ,

    , , .

    ,

    -

    . -

    , ,

    , .

    , , -

    , . -

    ,

    , .

    -

    () .

    20 . -

    , , -

    .

    ,

    .

    1

    - 2

    - 3

    - 6

    ? 9

    6

    4

    - 5

    6

    7

    - 8

    p

    p

    p

    p

    p

    p?

  • 10

    ,

    . -

    .

    -

    , , ,

    , .

    ,

    -

    .

    , -

    , Pear-

    son Eduation , .

    , | , -

    .

    2001

  • 1

    -

    . -

    ,

    , , -

    .

    . -

    , ,

    , .

    -

    -

    . |

    . , ,

    , -

    .

    | , -

    .

    | -

    , .

    -

    . -

    , ,

    . -

    1

    , -

    , .

    1.1.

    -

    , . 1.1.

    :

    ( ) -

    : , , , ,

    1

    Pasal | . | . .

  • 12 1.

    . 1.1.

    , .

    1.1.

    . -

    -

    .

    1.1

    | 120 147 142 107 81

    120 | 132 42 157 45

    147 132 | 108 66 105

    142 42 108 | 168 61

    107 157 66 168 | 112

    81 45 105 61 112 |

    , , |

    . -

    7. , . 1.2, -

    , -

    . 1.1.

    -

    ( ,

    ),

    , , -

    .

    1 ,

    ( ) .

  • 1.1. 13

    2 () ,

    , .

    3 2

    .

    132112

    168 108

    4261

    66

    142

    105 157

    45

    107

    147

    120

    81

    1.2.

    1.3, 1.4 1.5 ,

    , -

    . ( 339)

    ,

    .

    42

    45

    45

    1.3.

    , ,

    . ,

    , , -

    . ,

  • 14 1.

    , ? ,

    ! -

    | , -

    -

    .

    .

    105

    81

    81

    42

    42

    45

    45

    1.4.

    66

    105

    81

    42

    45

    1.5.

    1.2.

    , . -

    .

    begin

    ,

    end

    -

    , : -

    .

  • 1.2. 15

    :

    :

    =

    1.2.1. ( , First Seond ,

    Sum.)

    begin

    Input First and Seond ;

    Sum

    :

    =First + Seond ;

    end

    ,

    .

    :

    ; ; . ,

    -

    , . -

    :

    begin

    1;

    2;

    .........

    n;

    end

    1.2.2. ( : One

    Two.)

    begin

    Input One and Two;

    Temp

    :

    =One;

    One

    :

    =Two;

    Two

    :

    =Temp;

    end

    , , -

    One Two 5 7 -

    , . 1.2.

  • 16 1.

    1.2

    Temp One Two

    1 | 5 7

    2 5 5 7

    3 5 7 7

    4 5 7 5

    -

    . if-then

    if-then-else. :

    begin

    if then

    end

    :

    begin

    if then 1

    else 2

    end

    1.2.3. ( n -

    ab.)

    begin

    Input n;

    if n < 0 then ab

    :

    =nelse ab

    :

    =n;

    Output ab;

    end

    , ,

    n, |

    ( ). ,

    , else:

    begin

    Input n;

    if n < 0 then n

    :

    =n;ab

    :

    =n;

    Output ab;

    end

    -

    n .

  • 1.2. 17

    ,

    .

    :

    for X

    :

    =A to Z do ; (1)

    while do ; (2)

    repeat

    1;

    2;

    .............

    n;

    until .

    (3)

    X | , A Z | .

    (1) . -

    :

    for do

    (2) ,

    , , , .

    , .

    , (3)

    , . -

    (2) (3) , -

    ,

    .

    1.2.4. ( n

    .)

    begin

    sum

    :

    = 0;

    for i

    :

    = 1 to n do

    begin

    j

    :

    = i i;sum

    :

    = sum+ j;

    end

    Output sum;

    end

    n = 4, . 1.3

  • 18 1.

    1.3

    i j Sum

    | | 0

    1 1 1

    2 4 5

    3 9 14

    4 16 30

    : sum = 30.

    1.2.5. (

    ,

    .)

    begin

    v

    :

    = ;

    u

    :

    = ;

    v u;

    while do

    begin

    u

    :

    = ,

    ;

    u

    ;

    end

    end

    | , -

    .

    . , -

    ( ) (-

    . 7, . 146).

    | -

    ,

    .

    ,

    , -

    . |

    . -

    -

    . , , -

    1.2.5 ?

  • 1 19

    , , -

    , : -

    ? 1.5 -

    , ( -

    1.2.4). . ,

    ? ,

    ?

    : |

    ,

    .

    1

    1.1. . 1.6 , -

    .

    . , -

    , .

    A

    2

    3

    B

    D

    EF

    G

    3

    6

    3

    4

    3

    1

    2

    3

    5

    1.6.

    1.2.

    () n = 3;

    () n = 5.

    begin

    f

    :

    = 1;

    Input n;

    for i

    :

    = 1 to n do

    f

    :

    = f i;Output f ;

    end

  • 20 1.

    -

    n?

    1.3. i j -

    m = 3 n = 4:

    begin

    Input m, n;

    i

    :

    = 1;

    j

    :

    =m;

    while i 6= n dobegin

    i

    :

    = i+ 1;

    j

    :

    = j m;end

    Output j;

    end

    m n > 0. n = 0?

    1.4. ,

    :

    begin

    first

    :

    = 1;

    Output first;

    seond

    :

    = 1;

    Output seond;

    next

    :

    = first+ seond;

    while next < 100 do

    begin

    Output next;

    first

    :

    = seond;

    seond

    :

    =next;

    next

    :

    = first+ seond;

    end

    end

    .

    1.5. l, sum k -

    , n = 6.

  • 21

    begin

    Input n;

    k

    :

    = 1;

    l

    :

    = 0;

    sum

    :

    = 0;

    while k < 2n do

    begin

    l

    :

    = l + k;

    sum

    :

    = sum+ l;

    k

    :

    = k + 2;

    end

    Output sum;

    end

    -

    n.

    1.6. ,

    . 1.1. ?

    begin

    : 1, 2, 3, . . . . .;

    m

    :

    = ;

    :

    = ;

    :

    = 1;

    while > m 1 dobegin

    if

    then

    begin

    ;

    :

    = 1;end;

    :

    =+ 1;

    end

    end

    -

    ,

    .

  • 22 1.

    | ,

    .

    () -

    , ,

    () , .

    | , -

    .

    -

    ,

    .

    , -

    .

    .

    ,

    .

    (-

    ),

    , .

    -

    .

    -

    .

  • 2

    (). -

    , -

    , .

    , -

    .

    , -

    ( ) ,

    -

    . , -

    ,

    1

    . ,

    ( -

    , ),

    -

    , . ,

    ,

    .

    , , -

    .

    , -

    .

    2.1.

    -

    . , -

    , . . ( -

    ) ( ). ,

    ; | ; 29 | .

    1

    , ,

    .

  • 24 2.

    . ,

    , P , Q | -

    | R | 29 | .

    , , , ,

    , , -

    . ,

    ( P ) | ; (P Q) | | ; (P Q) | | .

    2.1. P | -

    , Q| .

    .

    () | , .

    () , | .

    () | , .

    .

    () ( P ) Q.

    () ( P ) ( Q).

    () P Q.

    -

    , -

    , . .

    .

    .

    P -

    ( P ), -

    P .

    . 2.1.

    2.1

    P ( P )

  • 2.1. 25

    P Q (P Q). -

    ,

    . -

    .

    | . 2.2.

    2.2

    P Q (P Q)

    P

    Q (P Q). ,

    ,

    -

    . , (P Q) , P ,

    Q, , . -

    . 2.3.

    2.3

    P Q (P Q)

    2.2. -

    : VIII

    , ,

    1

    ?

    . P -

    , Q | VIII

    R| . -

    : (P Q) ( R). , P ,

    Q R . (P Q) ( R)

    : ( ) , .

    1

    | , -

    XVII{XVIII .. -

    . | . .

  • 26 2.

    ,

    , , -

    . -

    .

    2.3. , ( (P ( Q))) -

    (( P ) Q).

    . (. 2.4)

    :

    R = ( (P ( Q))) S = (( P ) Q):

    -

    P Q.

    2.4

    P Q P Q P ( Q) R S

    . , -

    R S.

    , -

    . -

    : ,

    | .

    , -

    .

    P , Q. ,

    P , -

    , Q . P ,

    Q , -

    .

    2.4. P | () 1 = 5, Q |

    ( ) 3 = 7 R | () -

    4 = 4. , : P , Q

    P , R, | .

    . 1 = 5, , 2 ,

    , 3 = 7. , P , Q

  • 2.2. 27

    . 1 = 5

    3 2 = 2. (2)2 = 22, . . 4 = 4. , P , R .

    P , Q -

    , P ,

    Q . -

    .

    , P Q - P , Q. -

    P Q , P Q, P

    Q, Q P .

    . 2.5.

    2.5

    P Q (P Q)

    2.5. (( Q) ( P )) - (P Q)., (( Q) ( P )) - (P Q).. (. 2.6).

    2.6

    P Q P Q (P Q) (( Q) ( P ))

    ,

    , , .

    2.2.

    -

    , | ,

    . , ,

  • 28 2.

    .

    , ,

    . , x | , -

    x = x

    2

    ,

    x = 0 x = 1 .

    . -

    -

    . -

    , (-

    ),

    .

    2.6. ,

    ?

    () 180

    .

    () .

    () x, x

    2

    = 2.

    () .

    .

    () .

    () .

    1

    .

    () .

    () . 2 , .

    2.6 -

    , -

    , ()

    , .

    () -

    , , . , .

    .

    1

    | . | . .

  • 2.2. 29

    2.7. P (x) x |

    x

    2

    = 16. : x : P (x) .

    . x : P (x) , - x, x

    2

    = 16. ,

    , , x

    2

    = 16 -

    x = 4. , x = 4 | . -

    x, x : P (x).

    2.8. P (x) | : x |

    x

    2

    +1 = 0. : x : P (x) .

    . :

    x, x

    2

    + 1 = 0. -

    , . .

    x

    2 > 0, , x2 + 1 > 1. ,

    x : P (x) . 2.8 -

    : x : P (x). , , , , x, -

    x

    2

    + 1 = 0. ,

    x, x

    2

    + 1 6= 0. x P (x).

    P (x) -

    2

    :

    x : P (x) x P (x); x P (x) x : P (x).

    , -

    , .

    2.9. , x y | ,

    P (x; y) x+ y = 0. -

    .

    () x y : P (x; y);() y : x P (x; y).

    2

    . | . .

  • 30 2.

    .

    () x y : P (x; y) , x y,

    x+y = 0. , , , x

    , y = x x + y = 0 .

    () y : x P (x; y) : y, -

    x x+ y = 0. , -

    , : y,

    . , .

    2.3.

    .

    |

    . -

    ,

    (P Q). , :

    1. . , P -

    Q. -

    , P , Q | , -

    (P Q) (. . 2.5 . 27).

    2. . , Q

    P . , ,

    (( Q) ( P )), 2.5, -

    (P Q).3. . , P

    , Q , , -

    . - ,

    (P Q) , - P , Q .

    2.10. , -

    xy x y .

  • 2.3. 31

    . , ,

    x, x = 2m + 1, m |

    . , y = 2n+ 1 n.

    ,

    xy = (2m+ 1)(2n+ 1) = 4mn+ 2m+ 2n+ 1 = 2(2mn+m+ n) + 1

    .

    2.11. n | . , -

    , n

    2

    , n

    .

    . n

    2

    -

    n

    2

    , n -

    n . ,

    ,

    n n

    2

    .

    n , n = 2m - m. -

    , n

    2

    = 4m

    2

    = 2(2m

    2

    ) | .

    2.12. ,

    x

    2

    = 2 , . .

    .

    . , x

    x

    2

    = 2 , . . x =

    m

    n

    m n, n 6= 0. , , - -

    .

    ,

    . , x =

    m

    n

    =

    2m

    2n

    =

    3m

    3n

    . . -

    , m n .

    .

    , , x =

    m

    n

    -

    (m n ). x -

    x

    2

    = 2. ,

    (m

    n

    )2

    = 2, m

    2

    = 2n

    2

    .

    , m

    2

    . -

    , m (. . ())

    m = 2p - p. -

    m

    2

    = 2n

    2

    , , 4p

    2

    = 2n

    2

    , . . n

    2

    = 2p

    2

    .

    n . , -

    , m, n| .

  • 32 2.

    2. , -

    m

    n

    ,

    .

    :

    x

    2

    = 2 ,

    . . .

    2.4.

    , , -

    . ,

    - -

    , , -

    . -

    , .

    , , -

    , -

    .

    , -

    , -

    a

    1

    ; a

    2

    ; a

    3

    ; : : : ; a

    n

    .

    begin

    i

    :

    = 0;

    M

    :

    = 0;

    while i < n do

    begin

    j

    :

    = j + 1;

    M

    :

    =max(M; a);

    end

    end

    : a

    1

    = 4, a

    2

    = 7, a

    3

    = 3

    a

    4

    = 8 . 2.7.

    2.7

    j M j < 4?

    0 0

    1 4

    2 7

    3 7

    4 8

  • 2.4. 33

    M = 8, -

    . , -

    M ,

    .

    n?

    a

    1

    ; a

    2

    ; a

    3

    ; : : : ; a

    n

    n -

    M

    k

    M k- .

    1. a

    1

    1,

    M 0 a

    1

    ,

    , , a

    1

    ( 0).

    .

    2. k- M

    k

    |

    a

    1

    ; a

    2

    ; : : : ; a

    k

    , M

    k+1

    -

    max(M

    k

    ; a

    k+1

    ), . .

    a

    1

    ; a

    2

    ; : : : ; a

    k

    ; a

    k+1

    .

    . 1 , -

    1. . 2, -

    2. . 2

    , ,

    3, . . , -

    n, . .

    .

    -

    .

    P (n) | , -

    n.

    ,

    1. P (1)

    2. k > 1 (P (k) P (k + 1)) . P (n) n.

    2.13. ,

    1 + 2 + + n = n(n+ 1)2

    n.

  • 34 2.

    . P (n) | 1 + 2 + + n = n(n+1)2

    .

    n = 1 | 1,

    ,

    1(1 + 1)

    2

    = 1:

    , P (1) .

    , 1+2+ +k = k(k+1)2

    - k.

    1 + 2 + + k + (k + 1) = (1 + 2 + + k) + (k + 1) =

    =

    k(k + 1)

    2

    + (k + 1) =

    =

    1

    2

    (k(k + 1) + 2(k + 1)

    )=

    =

    1

    2

    ((k + 2)(k + 1)

    )=

    =

    (k + 1)(k + 2)

    2

    :

    , k

    P (k) P (k + 1)

    . , , -

    P (n) n.

    2.14. ,

    7

    n 1 6 n.. , a

    b ,

    a = mb - m. , 51 17,

    51 = 3 17. , - , ,

    b b.

    P (n) 7

    n 1 6. n = 1

    7

    n 1 = 7 1 = 6;. . P (1) .

    , 7

    k 1 6 - - k.

  • 2 35

    7

    k+1 1 = 7(7k) 1 == 7(7

    k 1) + 7 1 == 7(7

    k 1) + 6: 7

    k1 6, 7(7

    k 1) + 6 6., 7

    k+1 1 6, k (P (k) P (k + 1)) .

    P (n) n.

    2.15. x

    1

    ; x

    2

    ; : : : ; x

    n

    -

    :

    x

    1

    = 1 x

    k+1

    = x

    k

    + 8k k > 1:

    , : x

    n

    = (2n 1)2 n > 1.. x

    n

    = (2n 1)2 P (n). n = 1, (2n 1)2 = (2 1)2 = 1, P (1).

    , x

    k

    = (2k1)2 k > 1.

    x

    k+1

    = x

    k

    + 8k =

    = (2k 1)2 + 8k == 4k

    2

    + 4k + 1 =

    = (2k + 1)

    2

    :

    , x

    k+1

    =

    (2(k+1) 1)2 -

    (P (k) P (k + 1)) k > 1. , , P (n)

    -

    n.

    2

    2.1. P , Q R | -

    :

    P : .

  • 36 2.

    Q: .

    R: .

    -

    , P , Q R.

    () .

    () , .

    () , .

    () , .

    () , .

    2.2. P : , Q |

    . -

    :

    () , ;

    () ;

    () , ( -

    )

    .

    , -

    () ().

    2.3. ,

    , -

    . -

    :

    () (P ( P ));

    () P ( P );() (P (P Q)) Q.

    2.4. , (P Q) R - (( P ) R) (Q R).

    2.5. x , P (x) x

    .

    :

    () ;

    () ;

    () .

  • 2 37

    () ,

    () ,

    .

    2.6. P (x) x , Q(x) | x ,

    x | - . :

    x (P (x) Q(x)):

    :

    () ;

    () ;

    () .

    2.7. () -

    :

    n m | n+m | .() :

    n

    2

    | n | .() ,

    n+m | , | .

    2.8.

    .

    () 1+5+9+ +(4n3) = n(2n1) n.

    () 1

    2

    +2

    2

    + +n2 = 16

    n(n+1)(2n+1)

    n.

    ()

    1

    13 +1

    35 + + 1(2n1)(2n+1) =

    n

    2n+1

    n.

    () n

    3 n 3 - n.

    () 1 1!+2 2!+ +n n! = (n+1)!1 n.

    ( n! n -

    1 n :

    n! = 1 2 3 (n 1) n.)

  • 38 2.

    2.9. x

    1

    ; x

    2

    ; : : : ; x

    n

    -

    x

    1

    = 1 x

    k+1

    =

    x

    k

    x

    k

    + 2

    k > 1:

    x

    2

    , x

    3

    x

    4

    . ,

    x

    n

    =

    1

    2

    n 1 n > 1.

    2.10. x

    1

    ; x

    2

    ; : : : ; x

    n

    -

    x

    1

    = 1; x

    2

    = 2 x

    k+1

    = 2x

    k

    xk1 k > 1:

    x

    3

    , x

    4

    x

    5

    . x

    n

    .

    -

    .

    ,

    , . . .

    -

    . -

    , , ... .

    . 2.8 ,

    . 2.8

    P Q P Q P Q (P Q)

    -

    ,

    .

  • . 39

    x

    , , : P (x).

    () () | .

    (P Q) P Q.

    ( Q P ) (P Q).

    (P Q), - Q P ,

    .

    -

    , .

    | :

    P (n) | , -

    n.

    ,

    1. P (1)

    2. k > 1 (P (k) P (k + 1)) . P (n) n.

    .

    ( , -

    , , ), -

    , , -

    .

    .

    P | ,

    A, Q| , , -

    . {P}A {Q} , A -

    P , Q. P

    , Q |

  • 40 2.

    . {P}A {Q} - .

    A {P}A {Q}. .

    1. .

    begin

    z

    :

    =x y;end

    . P :

    x = x

    1

    y = y

    1

    . Q | z = x

    1

    y1

    .

    {P} {Q}

    x = x

    1

    y = y

    1

    , z = x

    1

    y1

    . -

    x = x

    1

    y = y

    1

    , z, x y. -

    : z = x y, x = x1

    y = y

    1

    z = x

    1

    y1

    .

    A

    , A

    1

    ; : : : ; A

    n

    {P}A1

    {Q1

    }; {Q1

    }A2

    {Q2

    }; : : : ; {Qn1}An {Q};

    .

    2. -

    .

    {x | }begin

    y

    :

    = ax;

    y

    :

    = (y + b)x;

    y

    :

    = y + ;

    end

    {y = ax2 + bx+ }

    . ,

    - .

  • . 41

    P {x = x1

    }begin

    y

    :

    = ax;

    Q

    1

    {y = ax1

    x = x

    1

    }y

    :

    = (y + b)x;

    Q

    2

    {y = ax21

    + bx

    1

    }y

    :

    = y + ;

    end

    Q {y = ax21

    + bx

    1

    + }

    , , , :

    {P} y := ax {Q1

    },{Q

    1

    } y := (y+ b)x {Q2

    },{Q

    2

    } y := y+ {Q}, |

    . ,

    {P} {Q}

    , . . .

    .

    if ... then,

    .

    : , -

    if then

    1;

    else

    2;

    P , Q.

    :

    {P } 1 {Q}

    {P ()} 2 {Q}.

  • 42 2.

    3. , .

    {x | }begin

    if x > 0 then

    ab

    :

    =x;

    else

    abs

    :

    =x;end

    {abs | x}

    . P {x = x1

    }, Q {abs| x}.

    {P x > 0} abs := x {Q} , x

    1

    -

    .

    {P (x > 0)} abs := x {Q} , x

    1

    .

    - ,

    while ... do, -

    .

    .

    4. -

    .

    {n | }begin

    sq

    :

    = 0;

    for i

    :

    = 1 to n do

    sq

    :

    = sq + 2i 1;end

    {sq = n2}

    . P (n) sq = n

    2

    n-

    , sq

    k

    | sq k-

    . ,

    (1) sq

    1

    = 1

    2

    ;

    (2) sq

    k

    = k

    2

    , sq

    k+1

    = (k + 1)

    2

    .

  • . 43

    , sq

    1

    = 1 (1)

    . , k- sq

    k

    = k

    2

    .

    sq

    k+1

    = sq

    k

    + 2(k + 1) 1 = k2 + 2k + 1 = (k + 1)2:

    , (2) .

    , , P (1) (. (1)). ,

    ((P (k) P (k + 1)) k > 1. ,

    , P (n) n.

    4 for

    (). , -

    , while ... do, -

    , -

    .

    , .

  • 3

    | ,

    , .

    -

    -

    . , ,

    .

    , -

    ,

    . -

    , ,

    , , -

    . ,

    , , , -

    , (

    ).

    .

    , I.

    3.1.

    | , -

    . ,

    {, , }; {2, 3, 5, 7, 11}; {, , , }.

    -

    . , -

    . -

  • 3.1. 45

    , S = {3; 2; 11; 5; 7} | , -. , S ,

    , , -

    , .

    a S , a | S. , a S.

    a S, : a 6 S. , -

    .

    .

    S = {x : P (x)} , x,

    P (x) . ,

    S = {x : x | }

    S = {1; 3; 5; 7; : : :}:

    2n 1, n | , :

    S = {2n 1 : n | }:

    3.1. , -

    .

    () A = {x : x | x2 + 4x = 12};() B = {x : x | , };() = {n2 : n | }.

    .

    () x

    2

    +4x = 12, x(x+4) = 12. x| ,

    12, 1, 2, 3, 4,6 12. , x + 4 12. : x = 6 x = 2. -

    x

    2

    + 4x 12 = 0. x = 6 x = 2., A = {6; 2}.

  • 46 3.

    () B = {, , }.() = {0; 1; 4; 9; 16; : : :}.

    , -

    .

    | ;

    N = {1; 2; 3; : : :} | ;Z = {0; 1; 2; 3; : : :} | ;Q = {p

    q

    : p; q Z; q 6= 0} | ;

    R = { }| . , -

    N 0.

    , -

    .

    . -

    ,

    .

    -

    . .

    , -

    -

    . , = {0; 1; 4; 9; 16; : : :} Z = {0; 1; 2; 3; : : :}.

    , A -

    S,

    S. ,

    A S. : A S. . 3.1 . -

    .

    , -

    .

    , .

    A = B

    :

    {x A x B} {x B x A}:

  • 3.1. 47

    S

    A

    3.1. A S

    3.2.

    A = {n : n2 | }

    B = {n : n | }:, A = B.

    . x A, x2 | . 2.11, , x |

    . , x B, . . A B. , x B. x |

    . 2.10, x

    2

    -

    , , x A. x B , B - A, . . B A. , A = B.

    A B

    A B = {x : x A x B}:

    , -

    A, B, .

    . 3.2.

    A B

    A B = {x : x A x B}:

    , A,

    B. . 3.3.

  • 48 3.

    A B

    3.2. A B

    A B

    3.3. A B

    1

    B A

    A \B = {x : x A x 6 B}:

    A \B A, B (. . 3.4).

    -

    U , U

    . -

    .

    A U -

    A U , . . U \ A. , -

    U \ A A 1

    . |. .

  • 3.1. 49

    A. , , -

    U ,

    A = {x : (x A)} A = {x : x 6 A}:

    . 3.5.

    A B

    3.4. A \ B

    A

    3.5. A

    A B

    A B = {x : (x A x 6 B) (x B x 6 A)}:

    , A B,

    , B, A. ,

    , A, B,

    . , ,

    . 3.6.

  • 50 3.

    A B

    3.6. A B

    3.3.

    A = {1; 3; 5; 7}; B = {2; 4; 6; 8}; C = {1; 2; 3; 4; 5}: A C, B C, A \ C B C..

    A C = {1; 3; 5; 7; 2; 4};B C = {2; 4};A \ C = {7};B C = (B \C) (C \B) = {6; 8}{1; 3; 5} = {6; 8; 1; 3; 5}.

    3.4.

    A = {x : 1 6 x 6 12 x };B = {x : 1 6 x 6 12 x , 3}:

    , (A B) = A B.. ,

    U = {1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12}: ,

    A = {2; 4; 6; 8; 10; 12} B = {3; 6; 9; 12}:

  • 3.2. 51

    (A B) = {6; 12} = {1; 2; 3; 4; 5; 7; 8; 9; 10; 11}

    A B = {1; 3; 5; 7; 9; 11} {1; 2; 4; 5; 7; 8; 10; 11} == {1; 2; 3; 4; 5; 7; 8; 9; 10; 11}:

    , (A B) = A B.

    3.2.

    , , -

    .

    , | , -

    .

    1

    -

    , . 3.1.

    3.1

    3.5. , A B

    : (A B) = A B..

    (A B) = {x : x 6 (A B)} == {x : (x (A B))} == {x : ((x A) (x B))};

    A B = {x : (x 6 A) (x 6 B)} == {x : ( (x A)) ( (x B))}:

    ,

    :

    (P Q) ( P ) ( Q);

    1

    , . | . .

  • 52 3.

    P Q | . -

    -

    (. 3.1), , (P Q) -

    (A B), ( P ) ( Q) | AB., (A B) = A B.

    , 3.5, , -

    . ,

    , .

    3.2.

    , , -

    3.5.

    (. 3.2)

    ,

    , U . - , |

    .

    3.2.

    A (B C) = (A B) C A (B C) = (A B) C

    A B = B A A B = B A

    A = A A U = A

    A U = U A =

    A A = A A A = A

    A (B C) = (A B) (A C) A (B C) = (A B) (A C)

    A A = U A A =

    U = = U

    A = A A = A

    (A B) = A B (A B) = A B

    -

    .

  • 3.3. 53

    . , ,

    , - -

    , .

    3.6. , ,

    A B :

    A B = (A B) (A B):

    . -

    :

    A B = (A B) (B A): , .

    (A B) (A B) = (. )= (A B) (A B)) = (. .)= ((A B) A) ((A B) B) = (. .)= (A (A B)) (B (A B)) = (. .)= ((A A) (A B)) ((B A) (B B)) = (. .)

    = ((A A) (B A)) ((A B) (B B)) = (. )= ( (B A)) ((A B) ) = (. .

    )

    = (A B) (B A)

    ,

    A B = (A B) (A B); .

    3.3.

    6 , ,

    . ,

    . ,

    ?

    ?

  • 54 3.

    S -

    . |S|. -

    . ,

    .

    .

    |A B| = |A|+ |B| |A B|:. . 3.7, A B - : A\B, AB B\A, . ,

    A = (A \B) (A B) B = (B \ A) (A B):

    :

    |A \B| = m; |A B| = n; |B \ A| = p:

    |A| = m+ n, |B| = n+ p

    |A B| = m+ n+ p == (m+ n) + (n+ p) n == |A|+ |B|+ |A B|:

    AB BAAB

    3.7.

  • 3.3. 55

    3.7. 63 ,

    ,

    . 16 , 37 |

    , 5 ,

    -

    ?

    . .

    A = {, };B = {, }:

    |A| = 16; |B| = 37; |A B| = 5:,

    |A B| = 16 + 37 5 = 48:, 6348 = 15 .

    ,

    ,

    .

    .

    , , -

    , . -

    .

    , -

    .

    (a; b), a| -

    A, b | B. -

    A B AB., A B = {(a; b) : a A b B}.

    , -

    -

    ,

    .

    3.8. A = {x; y} B = {1; 2; 3}. : AB, B A B B.. AB

    {(x; 1); (x; 2); (x; 3); (y; 1); (y; 2); (y; 3)}:

  • 56 3.

    B A |

    {(1; x); (2; x); (3; x); (1; y); (2; y); (3; y)}:

    , AB B A ! - B B

    {(1; 1); (1; 2); (1; 3); (2; 1); (2; 2); (2; 3); (3; 1); (3; 2); (3; 3)}:

    3.8, , -

    A B

    1

    |AB| = mn; |A| = m |B| = n:

    ,

    .

    , -

    . , A B 3.8 . 3.8

    x

    y

    ( 1)x, ( 2)x, ( 3)x,

    ( 1)y, ( 2)y, ( 3)y,

    1 2 3

    B

    A

    3.8.

    -

    R . RR R

    2

    , ,

    (x; y).

    . R2

    -

    . . 3.9

    1

    , , A

    ( m ) n . |

    . .

  • 3.3. 57

    A

    1

    ,

    A

    2

    , . . . , A

    n

    A

    1

    A2

    An

    = {(a1

    ; a

    2

    ; : : : ; a

    n

    ) : a

    i

    Ai

    ; i = 1; 2; : : : ; n}: | -

    , , -

    . -

    .

    .

    y

    x

    (3,2)

    3.9.

    , A

    1

    , A

    2

    , . . . , A

    n

    -

    A, A

    n

    n A.

    3.9. B = {0; 1}. Bn.. B

    n. -

    n.

    ,

    . S = {s1

    ; s

    2

    ; : : : ; s

    n

    }, - -

    . A S, n- (b

    1

    ; b

    2

    ; : : : ; b

    n

    ), b

    i

    = 1, s

    i

    A bi

    = 0 -

    . -

    A.

    , -

    , 1

    , 0 .

  • 58 3.

    3.10. S = {1; 2; 3; 4; 5}, A = {1; 3; 5} B = {3; 4}. A B,

    A B, A B B.. ,

    A a = (1; 0; 1; 0; 1), -

    B b = (0; 0; 1; 1; 0). ,

    a b = (1; 0; 1; 0; 1) (0; 0; 1; 1; 0) = (1; 0; 1; 1; 1);

    a b = (1; 0; 1; 0; 1) (0; 0; 1; 1; 0) = (0; 0; 1; 0; 0);

    b = (0; 0; 1; 1; 0) = (1; 1; 0; 0; 1):

    : AB = {1; 3; 4; 5}, AB = {3} B = {1; 2; 5}.

    3

    3.1. () :

    A = {x : x Z 10 6 x 6 17};B = {x : x Z x2 < 24};C = {x : x Z 6x2 + x 1 = 0};D = {x : x R 6x2 + x 1 = 0}:

    : 6x

    2

    + x 1 = (3x 1)(2x + 1):() -

    :

    S = {2; 5; 8; 11; : : :};T = {1; 1

    3

    ;

    1

    7

    ;

    1

    15

    ; : : :}.

    3.2. -

    U = {p; q; r; s; t; u; v; w}. A = {p; q; r; s}, B == {r; t; v} C = {p; s; t; u}. :

    () B C; () A C; () C;() A B C; () (A B); () B C.() (A B) (A C); () B \ C;

  • 3 59

    3.3.

    .

    A = {x : x | , };B = {x : x | , };C = {x : x | , }.

    , :

    () C A B;() B C;() B C;() A B = . :

    () A B C;() (A B) C.

    3.4. :

    A = {3n : n Z n > 4};B = {2n : n Z};C = {n : n Z n2 6 100}.

    () , -

    A, B C:

    (i) ;

    (ii) {10; 8; 6; 4; 2; 0; 2; 4; 6; 8; 10};(iii) {6n : n Z n > 2};(iv) {9; 7; 5; 3; 1; 1; 3; 5; 7; 9}.

    () A \B .3.5. ,

    :

    A (B C) = (A B) (A C):

    ,

    A, B C.

  • 60 3.

    3.6. , -

    :

    A (B C) = (A B) (A C):

    , A (B C) - (A B) (A C).

    3.7.

    :

    () (A B) B = A B;() (A (B C)) = A B C;() (A B C) (A B C) (A C) = ;() (A \B) \ C = A \ (B C);() A A A = A.

    3.8. :

    A B = (A B):

    A B. - :

    () A A = A;() (A A) (B B) = A B;() (A B C) (A B C) (A C) = ;() (A B) (A B) = A B.

    3.9. () , -

    A, B C :

    |A B C| ==|A|+ |B|+ |C| |A B| |B C| |A C|+ |A B C|:

    () , -

    , -

    . 25 -

    , 27 , 12 -

    . , 20 ,

    ,

    , | . ,

  • 61

    -

    .

    ?

    ?

    3.10. A B,

    AB = B A? A, B C

    A B = A C. , B = C? .

    3.11. A, B C | . ,

    () A (B C) = (AB) (A C);() (A B) C = (A C) (B C).

    3.12. P(A) , A.

    , P(A) = {C : C A}.() P(A), A = {1; 2; 3}.() , P(A)P(B) = P(AB) -

    A B.

    () , P(A)P(B) - P(A B).

    3.13. U = {1; 2; 3; 4; 5; 6} | . - :

    A = {1; 2; 4; 5} B = {3; 5}:

    AB A B, .

    | , -

    .

    , U | .

    N = {1; 2; 3; : : :} | .Z = {0; 1; 2; 3; : : :} | .Q = {p

    q

    : p; q , q 6= 0} | .R = { } | .

  • 62 3.

    S A, -

    S. : A S. ,

    .

    A B

    A B = {x : x A x B}: A B

    A B = {x : x A x B}: B A

    A \B = {x : x A x 6 B}: A ( U) -

    A = {x : x 6 A}: A B

    A B = {x : (x A x 6 B) (x B x 6 A)}: ,

    , U . S -

    . |S|. ,

    |A B| = |A|+ |B| |A B|: A B -

    AB = {(a; b) : a A b B}: AB . R R R2 . ( n) B

    n

    ,

    B = {0; 1}.

  • . 63

    .

    -

    .

    .

    .

    -

    , I. -

    , .

    ( I, II) (, I)

    ( III, IV) (, II)

    ( III, IV) (, III)

    ( III, ) (, IV)

    (, ) (, IV)

    (, VII) (, )

    (VII, V) (, VII)

    (V, VIII) ( , V)

    (V, VI) (, VI)

    (VI, II) ( II, )

    (, )

    (, )

    ( , {)

    ({, )

    , (x; y) , x -

    y, (x; y) , x | y.

    , , -

    , , , PROLOG.

    ,

    . , : I

    III?, , -

    ( I, 3) .

    : ? | . -

    , -

    . , ? | (x, IV)

    IV?.

    , , x , -

    , .

  • 64 3.

    1. :

    () ? | ( II, );

    () ? | (, II);

    () ? | ();

    () ? | (, II).

    .

    , -

    . , -

    ,

    .

    -

    , .

    ,

    . -

    , ,

    , .

    ,

    x, (x; y), . -

    (1) , ,

    x | y, x | .

    (1) (x) from (x; y).

    , (2), .

    , x | y, y | x.

    (2) (y; x) from (x; y).

    2. 1?

    :

    () ? | ({);

    () ? | (, );

    () ? | ().

    . () 1 -

    , (1), :

    (, IV).

    () , {-

    - .

  • . 65

    () | , -

    (, ) (2).

    (),

    .

    , -

    , (1):

    (3) (y) from (x; y)

    ,

    :

    (3) (x; y) from ((x) (y; x))

    3. :

    () ? | ( IV);

    () ? | ( IV, III);

    () ? | ( IV, );

    () ? | (VIII, V).

    .

    () (,

    IV) (3).

    () ( III,

    IV) ()

    (4).

    | .

    , () ()

    , -

    , . -

    ,

    . , III, -

    IV | , -

    III. , (4)

    ().

    () , -

    VIII. (3)

    ? | (VIII).

  • 66 3.

    , , -

    ,

    , ,

    .

    . , -

    -

    , .

    , , ,

    (A) (B):

    (A) (x) from (x; y);

    (B) (x) from ( (x)).

    : ? | (VIII), -

    , -

    (A) (B). ? | (VIII) -

    . -

    (VIII) . -

    (B) ? | (VIII) -

    ! , -

    ,

    .

    4. -

    -

    . (x) , -

    , x |

    - x | - . -

    (1)

    .

    ?

    . :

    (x) from ([(x; y) (z; y)

    [(x) (x; y)).

    [(x; y) (z; y)

    : , , , -

    . [(x) (x; y)

    .

  • . 67

    -

    , . , ,

    II.

    .

    , , -

    . ,

    .

  • 4

    , , -

    , , .

    (, ) -

    ,

    (, , . . ). -

    A B A B , -

    ,

    .

    S -

    K .

    S K - (s; k), : s

    k. ... -

    ...,

    .

    -

    .

    . , -

    : -

    . -

    , . -

    .

    n-

    .

    4.1.

    A B -

    R A B. , A = B, R A.

    4.1. ,

    . 4.1. ,

    P :

  • 4.1. 69

    () R = {(x; y) : x | y};() S = {(x; y) : x | y}.

    &

    &

    &

    4.1.

    .

    () R : (, ), (, -

    ), (, ), (, ), (, ) (,

    ).

    () S : (, ), (, ), (, -

    ), (, ), (, ), (, ), (, ),

    (, ) (, ).

    4.2. , -

    A = {1; 3; 5; 7} B = {2; 4; 6}:() U = {(x; y) : x+ y = 9};() V = {(x; y) : x < y}.

    .

    () U : (3; 6), (5; 4) (7; 2);

    () V = {(1; 2); (1; 4); (1; 6); (3; 4); (3; 6); (5; 6)}.

    4.3.

    R = {(x; y) : x | y}

    A = {1; 2; 3; 4; 5; 6}. , .

  • 70 4.

    . R : (1; 1), (1; 1), (1; 2), (1; 3), (1; 4), (1; 5),

    (1; 6), (2; 2), (2; 4), (2; 6), (3; 3), (3; 6), (4; 4), (5; 5) (6; 6).

    -

    , -

    . ,

    .

    A B | R | -

    . -

    . R

    , , -

    .

    , , ,

    .

    V -

    A = {1; 3; 5; 7} B = {2; 4; 6} 4.2 (). - . 4.2.

    1

    3

    5

    7

    2

    4

    6

    4.2. V A B

    A -

    ,

    A, , , ,

    .

    4.4. , R

    4.3.

    . R |

    A = {1; 2; 3; 4; 5; 6};

    .

    . 4.3.

  • 4.1. 71

    4.3. R A

    -

    . ,

    R A

    B.

    - . :

    A = {a1

    ; a

    2

    ; : : : ; a

    n

    }; B = {b1

    ; b

    2

    ; : : : ; b

    m

    }:

    R M n

    m . A,

    | B ,

    . ,

    i- j-

    M(i; j), :

    M(i; j) = ; (a

    i

    ; b

    j

    ) R;M(i; j) = ; (a

    i

    ; b

    j

    ) 6 R;

    nm . , U 4.2()

    :

    2 4 6

    1

    3

    5

    7

    :

  • 72 4.

    , -

    .

    .

    4.5. R A = {a; b; ; d} :

    ;

    -

    A. ,

    R.

    . R : (a; b),

    (a; ), (b; ), (b; d), (; b), (d; a), (d; b) (d; d).

    4.6. , R

    4.3.

    . R :

    1 2 3 4 5 6

    1

    2

    3

    4

    5

    6

    :

    R| , (x; y) R - xR y. , x|

    y . 4.3

    x | y -

    .

    , -

    ,

    :

    ( ); ; ; .

  • 4.2. 73

    4.7. R A = {1; 2; 3; 4} - . 4.7.

    -

    ,

    R, -

    .

    4.3.

    . R = {(2; 1); (3; 2); (4; 3)}. (

    ) :

    1 2 3 4

    1

    2

    3

    4

    :

    x y = 1:

    4.2.

    , -

    .

    , R A

    , x A xRx;, xR y y Rx x y A;, (xR y y Rx x = y) x y A;, (xR y y R z xR z) -

    x; y; z A. -

    . R , (x; x) R x; ,

    (x; y) R , (y; x) R; , : (x; y) R x 6= y , (y; x) 6 R; -, (x; y) R (y; z) R (x; z) R.

  • 74 4.

    , -

    , , . . , -

    . -

    x

    y , : y

    x. ,

    x y, y x -

    . , ,

    , x y

    y z x z.

    , . -

    , A -

    , . .

    . , M , ,

    , , -

    (M(i; i)), ; M -

    , . . M(i; j) =M(j; i); -

    :(M(i; j) = i 6= j)M(j; i) = :

    , -

    .

    4.8. (, -

    , )

    :

    () x y ;

    () x 6= y ;() x y

    .

    .

    () x , -

    . , , , , , 2

    6, : 6 2. ,

    . , x

    y, y z. -

    , y = mx

  • 4.2. 75

    m, | z = ny, n | -

    . , z = ny = (nm)x, . . x z. ,

    . , -

    , : x y y

    x , y = x.

    () x 6= x , -. , x 6= y , y 6= x. , , , 2 6= 3 3 6= 2, , , 2 = 2. ,

    x 6= y y 6= x , x = y.() , -

    x .

    , x

    y -

    y x. -

    , , x, y z,

    x y,

    y z, -

    . ,

    .

    R A

    , R

    ,

    . -

    -

    R AA , R . , R

    R

    . ,

    R

    R -

    , , R

    R

    .

    , R

    R -

    P ,

    1. R

    P ;

    2. R R;3. R

    , -

    R P .

  • 76 4.

    4.9. A = {1; 2; 3}, R A - :

    R = {(1; 1); (1; 2); (1; 3); (3; 1); (2; 3)}: , .

    .

    . -

    (x; x). ,

    :

    R

    = {(1; 1); (1; 2); (1; 3); (3; 1); (2; 3); (2; 2); (3; 3)};

    .

    , . ,

    R

    = {(1; 1); (1; 2); (1; 3); (3; 1); (2; 3); (2; 1); (3; 2)}:

    , -

    . R (3; 1)

    (1; 2), (3; 2). -

    , (2; 3) (3; 1) (2; 1), (3; 1)

    (1; 3) | (3; 3). :

    R

    {(1; 1); (1; 2); (1; 3); (3; 1); (2; 3); (3; 2); (2; 1); (3; 3)}: (2; 1) (1; 2). , -

    R

    (2; 2). ,

    ( ,

    A

    2

    ). ,

    R

    = {(1; 1); (1; 2); (1; 3); (3; 1); (2; 3); (3; 2); (2; 1); (3; 3); (2; 2)}:

    , -

    4.9, . 8 -

    , ,

    -

    .

    . -

    , , -

    .

    ,

    .

  • 4.3. 77

    4.3.

    .

    , -

    A . -

    -

    . (. .

    ), , - -

    .

    .

    ... , ... . , -

    ,

    .

    R, : xR y, xy > 0 -

    .

    .

    ... , ... .

    .

    , -

    ,

    . -

    . |

    .

    A -

    A

    1

    ; A

    2

    , . . .A

    n

    A,

    :

    1) A = A

    1

    A2

    An

    ;

    2) A

    i

    Aj

    = i 6= j. A

    i

    .

    A -

    . 4.4. , ,

  • 78 4.

    . ,

    .

    4.4.

    , R -

    A .

    .

    . E

    x

    -

    x A Ex

    = {z A : z Rx}. .

    . R |

    A.

    A.

    . .

    , -

    A. , E

    x

    |

    A. , R | , . . xRx. -

    , x Ex

    E

    x

    .

    , xR y E

    x

    = E

    y

    . -

    , xR y z Ex

    . z Rx

    xR y. R | , ,

    z R y. , z Ey

    . , E

    x

    Ey

    .

    , E

    y

    Ex

    , E

    x

    = E

    y

    , .

    , -

    , , A -

  • 4.3. 79

    .

    , E

    x

    | A

    -

    A. , x A, x Ex

    . -

    , x . ,

    A . ,

    A .

    , , , -

    . , -

    . -

    . , E

    x

    Ey

    6= . z A, E

    x

    Ey

    . ,

    z Rx z R y. R | , -

    , xR z z R y. R, xR y.

    , , E

    x

    = E

    y

    . , -

    , E

    x

    E

    y

    , . -

    .

    .

    , ,

    A, -

    : , -

    .

    4.10. R R

    : xR y, x y | . , R| -

    , 0,

    1

    2

    2.

    . x x = 0 Z x, R . x y , - y x = (x y) . ,R | . x y y z | . xz = (xy)+(yz) | , . . . , R .

    , , R , -

    . , R | .

    E

    x

    x :

    E

    x

    = {z R : z x | }:

  • 80 4.

    ,

    E

    0

    = Z;

    E

    1

    2

    = {z R : z 12

    | } =

    = {: : : ; 112

    ; 12

    ;

    1

    2

    ; 1

    1

    2

    ; 2

    1

    2

    ; : : :};

    E

    2

    = {z R : z 2 | } =

    = {: : : ; 1 +2;

    2; 1 +

    2; 2 +

    2; : : :}:

    , , R

    A . -

    , - -

    . ,

    , .

    .

    6 ; ; ... ... .

    -

    .

    R | A,

    x 6= y xR y x , y | .

    y . -

    x y, z,

    xR z z R y, x -

    1

    y x y.

    , . -

    A,

    x y, x y .

    -

    ,

    .

    1

    , y x. | . .

  • 4.3. 81

    4.11. , ... ... -

    A = {1; 2; 3; 6; 12; 18}. ,

    .

    . .

    4.1

    1

    2 1 1

    3 1 1

    6 1, 2, 3 2, 3

    12 1, 2, 3, 6 6

    18 1, 2, 3, 6 6

    12 18

    6

    2 3

    1

    4.5.

    A -

    ,

    .

    .

    6 ; . ,

    -

    . . -

    , ,

    2

    -

    2

    , . , -

    Z 6 ,

    . | . .

  • 82 4.

    ( ) (

    ).

    4.11

    , , 1. -

    , : 12 18. -

    .

    . ,

    {1; 2; 6; 18} - ... ....

    4

    4.1. -

    , :

    a b d

    1

    2

    3

    :

    4.2. -

    N , -

    :

    R ={(x; y) : 2x+ y = 9};S ={(x; y) : x+ y < 7};T ={(x; y) : y = x2}:

    4.3. R | {1; 2; 3; 4}, - : uR v , u + 2v |

    . R :

    () ;

    () ;

    () .

    4.4. ,

    , :

    () ... , ...;

    () ... ...;

    () ... , ...;

    () ... , ....

  • 4 83

    4.5. , Z

    , , -

    ?

    () x+ y | ;

    () x+ y | ;

    () xy | ;

    () x+ xy | .

    4.6. , -

    , {x : x Z 1 6 x 6 12}.() R = {(x; y) : xy = 9};() S = {(x; y) : 2x = 3y};() R ;

    () S .

    4.7. .

    .

    () x , y ;

    () x = 2y N ;

    () x < y R ;

    () x y .

    4.8. ,

    {(a; a); (b; b); (; ); (a; ); (a; d); (b; d); (; a); (d; a)

    };

    {a; b; ; d}. ?

    4.9.

    A ,

    A:

    () A | , R

    : xR y, x -

    y;

    () A = Z, R : xR y ,

    x y | ;() A| , xR y, x ,

    y;

  • 84 4.

    () A = R2

    , R : (a; b)R (; d) -

    , a

    2

    + b

    2

    =

    2

    + d

    2

    .

    4.10. R Z : xR y

    , x

    2y2 3. , R

    .

    4.11. -

    :

    () {1; 2; 3; 5; 6; 10; 15; 30} x - y;

    () {1; 2; 3} X | Y .

    4.12. R A =

    = {a; b; ; d; e; f; g; h} . 4.6. - R

    A.

    a b c

    d

    g

    e

    h

    f

    4.6.

    4.13. () -

    : X Y

    , ,

    . X -

    ( ), Y ,

    X Y ; X

    Y , , X -

    Y , , Y X.

  • 85

    : ,

    , , . ,

    .

    A B

    R A B. A = B, , R | - A.

    ( ), -

    , .

    R A

    , xRx x A;, xR y y Rx x; y A;, (xR y y Rx x = y)

    x; y A;, (xR y y R z) xR z x; y z A.

    R

    R -

    P ,

    1) R

    P ;

    2) R R;3) R

    | ,

    R P .

    , R -

    A .

    x A E

    x

    = {z A : z Rx}: A -

    A

    1

    ; A

    2

    ; : : : ; A

    n

    A, :

    A = A

    1

    A2

    An

    A

    i

    Aj

    = i 6= j: A

    i

    -

    . R | A, -

    A.

  • 86 4.

    , R

    A . ,

    , ,

    .

    | -

    , .

    R | A xR y,

    x 6= y, x y. , - x y z, xR z

    z R y, , x | -

    y. : x y.

    , -

    . ,

    x y, x - y .

    .

    , , . -

    ,

    ,

    ().

    4.2. T1 =

    .

    4000123 1.2.83 2 ,

    5001476 4.5.84 4 ,

    5112391 21.3.84 17 ,

    5072411 12.12.84 21 ,

    5532289 15.8.83 4 ,

    5083001 9.7.83 18 ,

    5196236 21.3.84 133 ,

    4936201 7.10.77 11 ,

    , , .

    , . 4.2 : -

    , , , , -

    . . 4.3

    .

  • . 87

    , -

    . , . 4.2

    , . 4.2 -

    , . 4.3.

    4.3. T2 =

    .

    . .

    . .

    n , A

    1

    ;

    A

    2

    ; : : : ; A

    n

    -

    A

    1

    A2

    An

    . n ,

    A

    i

    , n-

    .

    , . 4.3 T2

    A

    1

    A2

    A3

    A4

    A5

    , A

    1

    | ,

    A

    2

    = A

    3

    = A

    4

    = A

    5

    = {, , , }. | (, , , ,

    ), ,

    .

    , -

    , -

    , : , .

    , -

    ,

    , .

    . , (1, {, }) - . 4.4.

    1.

    (2, {, ., . .}).. . 4.5

  • 88 4.

    4.4. T3 = (1, {, })

    2 ,

    4 ,

    17 ,

    21 ,

    4 ,

    18 ,

    133 ,

    11 ,

    4.5

    .

    . .

    , -

    , -

    . , R S | ,

    , R | -

    A

    1

    Am

    B1

    Bn

    , S |

    A

    1

    Am

    C1

    Cp

    . -

    A

    1

    ; A

    2

    ; : : : ; A

    m

    . R S |

    A

    1

    Am

    B1

    Bn

    C1

    Cp

    , -

    (a

    1

    ; a

    2

    ; : : : ; a

    m

    ; b

    1

    ; b

    2

    ; : : : ; b

    m

    ;

    1

    ;

    2

    ; : : : ;

    p

    ),

    (a

    1

    ; : : : ; a

    m

    ; b

    1

    ; : : : ; b

    m

    ) R, (a

    1

    ; : : : ; a

    m

    ;

    1

    ; : : : ;

    p

    ) |

    S.

    , (3, 2) . 4.6.

    4.6

    . . .

    . .

    2 ,

    18 ,

    4 ,

    11 ,

    133 ,

  • . 89

    ,

    . , (1, = -

    =) . 4.7.

    4.7

    .

    5001476 4.5.84 4 ,

    5083001 9.7.83 18 ,

    2. (2, . .=).

    . (. 4.8) -

    2, , .

    .

    4.8

    . . .

    . .

    , -

    .

    3. , -

    :

    R1 = (T2, {, ., . });R2 = (R1, . = . = );

    . -, 2, -

    , . . , . -

    R1. ,

    , ,

    . R2 (. 4.9).

    4.9

    .

    .

  • 90 4.

    4. :

    R1 = (T1, =);

    R2 = (T2,{, . .});R3= (R1, R2).

    . 1 , -

    , R1.

    2 , , R2.

    R1 R2 .

    R1 R2, (. 4.10).

    4.10

    .

    . .

    4000123 1.2.83 2 ,

    5196236 21.3.84 133 ,

    4936201 7.10.77 11 ,

    5. (, -

    ) -

    , :

    .

    . -

    .

    R1=(1, =);

    R2=(2, . .= . .=);

    R3=(R2,.= .=);

    R4= (R1, R3);

    R=(R4,{, }).

  • 5

    , -

    ,

    - .

    | , -

    .

    ,

    . ,

    , -

    , 4.

    .

    -

    . -

    , . -

    , -

    , . ,

    , -

    .

    , -

    . -

    , -

    ( ). ,

    .

    5.1.

    R | A B. -

    R

    1 B A :

    R

    1= {(b; a) : (a; b) R}:

    , ... ...

    ... ....

    -

    , .

  • 92 5.

    . R |

    A B, S |

    B C. R S

    A C,

    S R :S R = {(a; ) : a A; C aR b; b S b B}:

    A C, B .

    5.1. R | a | b, S -

    b | .

    : S R S S.. a | b, b | , a, ,

    , . . a . ,

    S R , a | . , S S |

    a | .

    5.2. , R S -

    , . 5.1. , -

    S R.a

    b

    R S

    x

    y

    1 1

    2 2

    3 3

    5.1. R S

    . , , -

    .

    R = {(a; 1); (a; 2); (a; 3); (b; 2)} S = {(1; y); (2; x); (3; x)}: .

    aR 1 1S y (a; y) S R;aR 2 2S x (a; x) S R;

  • 5.1. 93

    aR 3 3S x (a; x) S R;bR 2 2S x (b; x) S R:

    . 5.2 .

    a

    b

    x

    ySR

    5.2. S R

    -

    , . ,

    .

    .

    :

    A = {a1

    ; a

    2

    ; : : : ; a

    n

    }; B = {b1

    ; b

    2

    ; : : : ; b

    m

    } C = {1

    ;

    2

    ; : : : ;

    p

    }:, R | A B, S |

    B C. , M R

    :

    M(i; j) = (a

    i

    ; b

    j

    ) R;M(i; j) = (a

    i

    ; b

    j

    ) 6 R:, N S :

    N(i; j) = (b

    i

    ;

    j

    ) S;N(i; j) = (b

    i

    ;

    j

    ) 6 S: b

    k

    B, ai

    Rb

    k

    b

    k

    S

    j

    ,

    i- M k- . , j-

    N k- .

    , -

    a

    i

    (S R) j

    , P (i; j) P -

    S R . i- M , j-

    N , P (i; j) = .

  • 94 5.

    , P S R - :

    P (i; j) = [M(i; 1) N(1; j)

    [M(i; 2) N(2; j)

    ::::::::::::::::::::::::::::::::::::::::

    [M(i; n) N(n; j):

    P =MN .

    5.3. R S | 5.2.

    S R - R S.

    . R A = {a; b} B = {1; 2; 3}

    M =

    [

    ];

    A B

    , .

    , S | B = {1; 2; 3} C = {x; y},

    N =

    :

    , P S R

    P =

    [

    ]

    :

    M , N | . -

    P .

    P (1; 1) M -

    N . ,

    P (1; 1) =

    [

    ]

    = ( ) ( ) ( )

    = = :

  • 5.1. 95

    , M

    , N .

    : P (1; 1) = .

    M -

    N , ,

    . , P (1; 2) = .

    , M

    N , P (2; 1) = .

    , P (2; 2) = , M -

    N .

    ,

    N =

    [

    ]:

    5.4. R A = {1; 2; 3; 4; 5} -

    :

    R R , - R .

    . R R

    =

    :

    R R (x; z), xR y y R z - y A. R - R R R. , , , R R - , R. R

    .

  • 96 5.

    5.2.

    , A B. |

    , -

    .

    A B -

    , A

    B. , -

    a A (a; b). ,

    , -

    A, .

    , . 5.3 , -

    {a; b; } {1; 2}, (a; 1), (b; 1) (; 2).

    a

    b

    c

    1

    2

    5.3.

    5.5. ,

    A = {a; b; } B = {1; 2; 3} A B.

    () f = {(a; 1); (a; 2); (b; 3); (; 2)};() g = {(a; 1); (b; 2); (; 1)};() h = {(a; 1); (; 2)}.

    .

    () f | , a -

    B: 1 2.

    () g .

    () , -

    b .

  • 5.2. 97

    5.6. :

    () x | y ;

    () Z, : {(x; x2) : x Z};() R, : {(x; y) : x = y2}

    ?

    .

    () ,

    , .

    () ,

    x x

    2

    .

    () | , , ,

    : (2;

    2) (2; 2) | .

    , (x; y) x.

    f | A B.

    x A - y B, , (x; y) f , : y = f(x), -, f A B,

    f(x) x f f ,

    x.

    , f : A B, , f A B. -

    A , B |

    1

    f .

    ,

    A f ,

    . , f

    B,

    x A. f(A) :

    f(A) = {f(x) : x A}: . 5.4 -

    , A B.

    1

    , f A

    B. | . .

  • 98 5.

    f

    A B

    f(A)

    5.4. f : A B

    f : A B, A B | - , .

    -

    , , .

    5.5. y = f(x)

    , f : R R, f(x) = x

    2

    , . 5.5. x

    R. -

    y (

    R). , . . ,

    (x; y) R R, y = f(x). ,, f(2) = 4, (2; 4) ,

    .

    5.7. g : R R, g(x) = 2 x. x = 2 x = 3. .

  • 5.2. 99

    . . 5.6. -

    : g(2) = 0 g(3) = 1.y

    x

    (2,0)

    (3, 1)-

    5.6. g(x) = 2 x

    .

    f : A B | . - , ,

    f(a

    1

    ) = f(a

    2

    ) a1

    = a

    2

    a

    1

    ; a

    2

    A. ,

    a

    1

    6= a2

    f(a1

    ) 6= f(a2

    );

    . . .

    , .

    f ,

    ,

    . , b B a A, b = f(a). , - - f .

    f ,

    , .

    5.8. , ,

    . 5.7, , . -

    .

  • 100 5.

    a

    b

    c

    a

    b

    c

    a

    b

    c

    a

    b

    1

    2

    3

    1

    2

    3

    1

    2

    1

    2

    3

    ()

    ()

    ()

    ()

    5.7.

    .

    () , 1 -

    a, b. ,

    , 2 .

    () , -

    . ,

    .

    () 1 a, b. -

    , . -

    ,

    .

    () , .

    () .

    5.9. , h : Z Z, - h(x) = x

    2

    , .

    . , -

    f : R R, f(x) = x2, . -

    , h

  • 5.2. 101

    . h, . 5.8,

    .

    -3-2 -1

    1 2 3

    1

    4

    9

    y

    x

    5.8. h(x) = x

    2

    , Z.

    , h ,

    a

    1

    6= a2

    , h(a

    1

    ) = h(a

    2

    ).

    . , a

    1

    = 2 a

    2

    = 2. , -

    , , -

    h. -

    . , -

    1, .

    5.10. , k : R R, - k(x) = 4x+ 3, .

    . , k(a

    1

    ) = k(a

    2

    ), . .

    4a

    1

    + 3 = 4a

    2

    + 3:

    , 4a

    1

    = 4a

    2

    , a

    1

    = a

    2

    . , k |

    .

    b R. , a R, h(a) = b. , a a = 1

    4

    (b3)., k | .

    k ,

    | .

  • 102 5.

    5.3.

    , f : A B | -. f

    1.

    , -

    f

    1: B A

    .

    f (a; b), b = f(a). f -

    , f

    1 (b; a), a = f

    1(b).

    , :

    f(a) = b, f

    1(b) = a. , -

    .

    5.11. 5.8 ?

    .

    , . , -

    () .

    .

    k : R R, k = 4x + 3 (. 5.10). k :

    -x

    4

    -4x

    3

    -4x+ 3

    : 4 3 |

    : 4 3, .

    , :

    1

    4

    (x 3)

    4

    (x 3)

    3

    x

    , k

    1: R R k1 = 1

    4

    (x 3). , -

    . y = k(x), x = k

    1(y).

    , y = 4x+ 3. y, -

    , x =

    1

    4

    (y3). , k1(y) = 14

    (y3) , - x , k

    1(x) =

    1

    4

    (x3), .

  • 5.3. 103

    , ,

    , . : -

    .

    f : A B.. f ,

    .

    . .

    , .

    f : A B | . , f :

    f =

    {(a; b) : a A f(a) = b}:

    :

    f

    1=

    {(b; a) : a A f(a) = b}:

    f , b B a A, f(a) = b. , - f a b .

    , f

    1 ,

    B

    A. , , , f

    1

    , .

    , -

    . , f

    1| .

    b B a A, - (b; a) f1. , (a; b) f , . . b = f(a). f .

    f

    . , f(a

    1

    ) = f(a

    2

    ). : (f(a

    1

    ); a

    1

    )

    (f(a

    2

    ); a

    2

    ) | f

    1. f

    1 ,

    : a

    1

    = a

    2

    , f .

    , f , . -

    : ,

    , .

    5.12.

    A = {x : x R x 6= 1} f : A A :

    f(x) =

    x

    x 1 :

  • 104 5.

    , f .

    . , f(a

    1

    ) = f(a

    2

    ).

    a

    1

    a

    1

    1 =a

    2

    a

    2

    1 :

    ,

    a

    1

    a

    2

    a1

    = a

    1

    a

    2

    a2

    ;

    a

    1

    = a

    2

    . , f .

    b A | f . a A, : f(a) = b, . .

    a

    a 1 = b:

    a,

    a =

    b

    b 1 :

    a =

    b

    b1 A, f(a) = b. f .

    , , f , -

    . , .

    : f

    1(b) = a ,

    f(a) = b. , -

    f ,

    a =

    b

    b 1 :

    , f

    1: A A,

    f

    1(x) =

    x

    x 1 ;

    . . f .

    .

    ,

    , .

    f : A B g : B C | , g f A C (a; ), b B (a; b) f (b; ) g. b = f(a) a, f | . -

    , = g(b) b (g

  • 5.4. 105

    ). , = g(f(a)) -

    a , ,

    f g | .

    , g f : A C , - (g f)(x) = g(f(x)). 5.13. : f : R R, f(x) = x2 g : R R, g(x) = 4x+ 3. g f , f g, f f g g.. R -

    R.

    (g f)(x) = g(f(x)) = g(x2) = 4x2 + 3;(f g)(x) = f(g(x)) = f(4x+ 3) = (4x+ 3)2 = 16x2 + 24x+ 9;(f f)(x) = f(f(x)) = f(x2) = x4;(g g)(x) = g(g(x)) = g(4x+ 3) = 4(4x + 3) + 3 = 16x+ 15.

    -

    .

    . -

    , -

    sinx, log x, |x| . . , .

    ,

    , -

    . |

    , , -

    . , -

    .

    .

    5.4.

    f : A B | , A, B | - . , A n :

    a

    1

    ; a

    2

    ; : : : ; a

    n

    . , |A| > |B|, f

    1

    .

    , a

    i

    6= aj

    , f(a

    i

    ) = f(a

    j

    ).

    1

    ,

    : 10 9 ,

    . | . .

  • 106 5.

    , ,

    i 6= j : f(ai

    ) 6= f(aj

    ).

    B n :

    f(a

    1

    ); f(a

    2

    ); : : : ; f(a

    n

    ). , |B| > n, - : n = |A| > |B|. , a

    i

    ; a

    j

    A, f(ai

    ) = f(a

    j

    ).

    5.14. 15 . ,

    .

    . A, -

    12 B.

    f : A B, . |A| = 15, |B| = 12, |A| > |B|. - f , . .

    .

    5.14 -

    . 15 12 . -

    , .

    , -

    , . ,

    ,

    , , , -

    . | -

    . ,

    , , f -

    ( A)

    ( B). -

    .

    5.15. -

    ,

    ,

    ?

    . A | , B |

    , -

    , 33 . f : A B, -

    : . ,

    f() = (; ). B 33 33 = 1 089 . , |A| > |B| = 1089,

  • 5.4. 107

    , -

    .

    1 090

    2

    .

    5.16. , 1, 2, 3, 4, 5, 6,

    7 8 , ,

    9.

    . , 9.

    {1; 8}; {2; 7}; {3; 6}; {4; 5}: A ( -

    ), B :

    B =

    {{1; 8}; {2; 7}; {3; 6}; {4; 5}}: f : A B, B, . -

    , f(3) = {3; 6}. A . ,

    9.

    . -

    f : A B, A B | . |A| > k|B| k,

    f , k+1 .

    ,

    f k , A

    k|B| . 5.17. -

    ,

    ,

    ?

    . f : A B | 5.15. , B 1 089 .

    -

    , , |A| > 4|B| = 4356. , - 4 357 .

    2

    , ,

    . . | . .

  • 108 5.

    5.18. ,

    , , ,

    .

    . x| , A| -

    B = {0; 1}. f : A B :

    f(a) =

    {0; a x;

    1; a x:

    5 = |A| > 2|B|, , x, .

    , a, b x.

    ,

    . , - , a b

    . x. , : a, b x|

    . ,

    , x .

    , -

    ,

    , . , -

    A B. ,

    , -

    ,

    , -

    .

    5

    5.1. R |

    {1; 2; 3} {1; 2; 3; 4};

    :

    R =

    {(1; 1); (2; 3); (2; 4); (3; 1); (3; 4)

    }:

    , S |

    {1; 2; 3; 4} {1; 2};

  • 5 109

    :

    S =

    {(1; 1); (1; 2); (2; 1); (3; 1); (4; 2)

    }:

    R

    1, S

    1 S R. ,

    (S R)1 = R1 S1:

    5.2. R | ... ..., S |

    ... ... . -

    : R

    1, S

    1, RS, S1 R1 RR.

    5.3. , R |

    A, R

    1 -

    A.

    -

    R R

    1?

    5.4. R S M N ,

    M =

    [

    ] N =

    :

    MN . -

    ?

    5.5. A = {0; 2; 4; 6} B = {1; 3; 5; 7}. - A B

    , A B?

    ()

    {(6; 3); (2; 1); (0; 3); (4; 5)

    };

    ()

    {(2; 3); (4; 7); (0; 1); (6; 5)

    };

    ()

    {(2; 1); (4; 5); (6; 3)

    };

    ()

    {(6; 1); (0; 3); (4; 1); (0; 7); (2; 5)

    }.

    , -

    ?

    5.6. , -

    Z, ,

    , .

    () f(n) = 2n+ 1;

  • 110 5.

    () g(n) =

    {n

    2

    ; n ;

    2n; n ;

    () h(n) =

    {n+ 1; n ;

    n 1; n :5.7. :

    () f : Z Z, f(x) = x2 + 1;() g : N N, g(x) = 2x;() h : R R, h(x) = 5x 1;

    () j : R R, j(x) ={

    2x 3 x > 1;x+ 1 x < 1;

    () k : R R, k(x) = x+ |x|;() l : R R, l(x) = 2x |x|. , -

    , (|x| x, x x > 0 x x < 0).

    5.8. , , -

    x , -

    x, : x.() A = {1; 0; 1; 2} f : A Z -

    : f(x) =

    x

    2

    +1

    3

    :

    f .

    () , g : Z Z,

    g(n) =

    n

    2

    , .

    5.9. f : A B : f(x) = 1 + 2x

    , A

    , 0,

    B | 1. ,

    f .

    5.10. f : R R g : R R :

    f(x) = x

    2

    g(x) =

    {2x+ 1; x > 0;

    x; x < 0:

    : f g, g f g g.

  • 5 111

    5.11. f : A B g : B C | . , () f g , g f ;() f g , g f ;() f g , (g f)1 = f1 g1.

    5.12. () ,

    - ?

    () ,

    :

    ?

    () -

    52 ,

    ?

    () -

    52 ,

    ?

    5.13. , 79 ,

    2 .

    () , ,

    , . .,

    ,

    | .

    () ,

    .

    5.14. S = {1; 2; : : : ; 20}.()

    S,

    22?

    () , 11 S,

    -

    - .

    (: f , -

    -

    . , f(12) = 3.)

  • 112 5.

    R A B

    R

    1; -

    B A : R

    1=

    {(b; a) : (a; b) R}.

    R | A B, S | -

    B C. -

    R S A C,

    :

    S R = {(a; ) : a A; C aR b; b S b B}: M N | R S -

    . MN

    S R.

    , A B, -

    f A B,

    A B.

    f : A B A - B. A f ,

    B | f . y = f(x),

    , y B | f , x. y x -

    f .

    f B:

    f(A) =

    {f(x) : x A} ( ).

    f : A B ( ), f(a

    1

    ) = f(a

    2

    ) a1

    = a

    2

    a

    1

    ; a

    2

    A.

    f : A B , - . ,

    b B a A, f(a) = b.

    , , ,

    .

    f , -

    f . f : A B

  • . 113

    , . f

    f

    1: B A. f(a) = b, f1(b) = a.

    , f : A B | -, A B,

    |A| > |B|, f . |A| > k|B| k, f k+1 .

    .

    ,

    .

    , -

    , -

    .

    -

    , -

    . , -

    , .

    , -

    ,

    .

    C =

    {; ; ; : : : ;

    }| -

    , P

    {0; 1; 2; : : :

    }. S (-

    ) . , | -

    S, .

    , -

    :

    har : S C, har(s) | s.

    rest : S S, rest(s) | , s .

    addhar : CS S, addhar(; s) | , - s .

    len : S P, len(s) | s.

  • 114 5.

    ,

    , . -

    , ,

    | -

    .

    1.

    har(s),

    len(rest(s))

    addhar

    (

    har(s); addhar

    (; rest(s)

    )),

    s = .

    .

    har(s) = har() = ;

    len(rest(s)) = len(rest()) = len() = 2;

    addhar

    (

    har(s); addhar

    (; rest(s)

    ))=

    = addhar

    (; addhar

    (; rest()

    ))=

    = addhar

    (; addhar(; )

    )=

    = addhar(; ) = .

    2.

    addhar(har(s); addhar(;rest(s)));

    s | , | .

    . ,

    s.

    3. third : S C - .

    third har rest.

    . s -

    , s

    .

    third(s) = har(rest(rest(s))):

  • . 115

    4. ,

    reverse2 : S S, 2 .

    . s | . -

    har(rest(s)), | har(s).

    rest(rest(s)). -

    , reverse2(s)

    :

    addhar(har(rest(s)); addhar(har(s); rest(rest(s)))):

    5. , -

    s = .

    Input s

    begin

    u

    :

    = ;

    t

    :

    = s;

    i

    :

    = 0;

    while i < len(s) do

    :

    =har(t);

    t

    :

    =rest(t);

    u

    :

    =addhar(; u);

    i

    :

    = i+ 1;

    end

    Output u

    ?

    . , t, u

    i while

    . 5.1

    5.1

    t u i i < 4?

    0 | 0

    1 1

    2 2

    3 3

    4 3

    .

  • 116 5.

    , -

    . , rest

    s = , reverse2 -

    2. , -

    ,

    . -

    . ,

    .

    , rest -

    :

    rest : S S, : s S s 6= ,

    rest(s) | , s, .

    , -

    . , ,

    rest(rest(s)) 1 ,

    rest rest | s S len(s) > 1.

  • 6

    , -

    . ,

    ,

    . , -

    ( 3) ( 5).

    , -

    :

    .

    .

    , :

    ,

    .

    . -

    -

    , .

    ,

    :

    (x

    1

    + x

    2

    + + xk

    )

    n

    :

    , -

    .

    ,

    .

    , -

    .

    6.1.

    .

    1.

    : ,

    .

    .

    ?

  • 118 6.

    2. ,

    . -

    6 9 .

    ?

    3. 3 4?

    . -

    , .

    4+2+3 = 9 ,

    .

    6 ,

    ,

    . ,

    , , 69 = 54. -

    .

    , A B | -

    , n

    1

    A, n

    2

    -

    B,

    A B n

    1

    + n

    2

    .

    , -

    k n

    1

    , n

    2

    | -

    , . ., n

    k

    ,

    k

    n

    1

    n2

    nk

    .

    , , | -

    . , A B

    , |A| = n1

    , |B| = n2

    ; A

    B , , -

    . ,

    , |A B| = |A| + |B|, . . A B n

    1

    +n

    2

    . , n

    1

    +n

    2

    A B.

    -

    . A

    1

    n

    1

    , A

    2

    | n

    2

    , . .

    k

    A

    1

    A2

    Ak

    ,

    |A1

    | |A2

    | |Ak

    |. .

    , -

    . , , -

  • 6.1. 119

    .

    , 3, -

    | 4. , -

    (

    3), 10 10 .

    ,

    1 10 10 = 100. . 100. ,

    , 100 + 100 = 200 -

    , 3 4.

    6.1. .

    , .

    ?

    .

    , 3 4 = 12 -

    1

    . 3 2 = 6 ., 4 2 = 8 -. ,

    , ,

    12 + 6 + 8 = 26.

    6.2.

    ( ). , -

    . -

    ?

    . 33

    . -

    33 33 33 = 35 937. , 10 10 10 = 1 000. ,

    , : 35 937 000

    .

    1

    : -

    .

    , . | .

    .

  • 120 6.

    6.2.

    , -

    : (A), - (B)

    (C).

    ?

    . , ,

    . ,

    , . . AA? ,

    ? ,

    AB BA ?

    -

    .

    1. .

    9 : AA, AB, AC, BA, BB, BC,

    CA, CB CC.

    2. ,

    . | 6 : AB, AC, BA, BC,

    CA CB.

    3. , .

    | 6 : AA, AB, AC, BB, BC

    CC.

    4. , , ,

    ,

    : AB, AC BC.

    , -

    .

    , .

    . , -

    x

    1

    ; x

    2

    ; : : : ; x

    k

    X k.

    k n -

    , , (n; k)-. -

    , .

    ,

    , . -

    , -

    .

    , .

  • 6.2. 121

    (n; k)- - (n; k)-, ;

    (n; k)- - (n; k)-, -

    ;

    (n; k)- - (n; k)- ;

    (n; k)- (n; k)- .

    (n; k)--

    . -

    n .

    ,

    , . . k

    , , , -

    (n; k)- n

    k

    .

    6.3.

    N . (+ ), N 1 . - ?

    . | 0 1. -

    N . , , -

    , ,

    , , .

    (2; N)- . -

    , 2

    N

    .

    , :

    000000 00 + 000000 00; 0. ,

    (2

    N 1) . (n; k)-

    1

    : P (n; k). . -

    n . -

    ,

    1

    A

    k

    n

    . | .

    .

  • 122 6.

    (n 1) . - | (n 2) , k- , (nk+1) . .

    P (n; k) = n(n 1)(n 2) (n k + 1):

    , -

    1 n n -

    n!.

    P (n; k), , -

    .

    P (n; k) = n(n 1)(n 2) (n k + 1) =

    = n(n 1)(n 2) (n k + 1)(n k)(n k 1) 2 1(n k)(n k 1) 2 1 =

    =

    n(n 1)(n 2) (n k + 1)(n k)(n k 1) 2 1(n k)(n k 1) 2 1 =

    =

    n!

    (n k)! :

    , (n; k)-

    P (n; k) =

    n!

    (n k)! :

    6.4.

    , : , , , ,

    ,

    .

    . ,

    ,

    . -

    P (6; 4). ,

    P (6; 4) =

    6!

    (6 4)! =6!

    2!

    =

    6 5 4 3 2 12 1 :

    :

    P (6; 4) =

    6 5 4 3 62 6162 61 = 6 5 4 3 = 360:

  • 6.2. 123

    , . . ,

    .

    (n; k)-

    2

    C(n; k).

    .

    : (n; k)-

    P (n; k) =

    n!

    (nk)! . -

    , P (n; k), , C(n; k).

    , .

    . n = 4, k = 3. -

    A = {1; 2; 3; 4}, . (4; 3)- |

    , ,

    , . , -

    {1; 2; 3} (4; 3)- . - {2; 1; 3}, ( ),

    ( ). -

    ? -

    , .

    (n = 4, k = 3) ,

    . . -

    .

    (n; k)- , . . -

    B A, |B| = k |A| = n. (n; k)- ?

    , (k; k)-

    ! (, .)

    3

    :

    P (k; k) =

    k!

    (k k)! = k!:

    , (n; k)- -

    k! (n; k)- . ,

    C(n; k) =

    P (n; k)

    k!

    =

    n!

    (n k)! k! :

    2

    C

    k

    n

    , ,

    , :

    `n

    k

    . | . .

    3

    , 0! = 1. | . .

  • 124 6.

    6.5.

    .

    ?

    . (7; 3)- -

    . :

    C(7; 3) =

    7!

    (7 3)! 3! =7!

    4! 3!

    =

    7 6 5 4 3 2 1(4 3 2 1)(3 2 1) =

    =

    7 6 5 64 63 62 61(64 63 62 61)(3 2 1) =

    7 66 563 62 61 = 35:

    , 35 .

    , , . -

    , , , -

    .

    , ,

    , - -

    .

    , , ,

    , a, .

    , , , -

    ||, : ||. , - , , |

    , , , -

    , . , ,

    ( ),

    ,

    . , -

    ,

    . ,

    , (7; 2)- , . . -

    C(7; 2). ,

    , | , -

    . 7 6 . , , -

    . , 7 6 2. ,

  • 6.2. 125

    7 62

    =

    7 6 5 4 3 2 1(2 1)(5 4 3 2 1) =

    =

    7!

    5! 2! =7!

    (7 2)! 2! = C(7; 2):

    (n; k)-

    (k n ), , n 1 - k . , (n 1) + k . , (n; k)- -

    (n 1) (n+ k 1). , (n; k)-

    C(n+ k 1; n 1) = (n+ k 1)!(n+ k 1 (n 1))! (n 1)! =

    (n+ k 1)!k! (n 1)! :

    6.6. , -

    ?

    . -

    , . . .

    , -

    ( 6

    ) , . . (6; 5)- -

    . ,

    C(6 + 5 1; 6 1) = C(10; 5) = 10!5! 5!

    = 252:

    . 6.1 -

    k n- ,

    .

    6.1

    n

    k

    (n+ k 1)!

    k! (n 1)!

    n!

    (n k)!

    n!

    (n k)! k!

    , -

    , -

    .

  • 126 6.

    4

    -

    49 -

    . , ,

    , -

    .

    . -

    |

    49 . (49; 6)-

    49!

    (49 6)! 6! =49!

    43! 6!

    = 13 983 816;

    : 1 13 983 816. -

    , , .

    , , , -

    , .

    , , ,

    , ,

    .

    , ,

    . ,

    , $1 ( ), ,

    ( ) , -

    $10. $10.

    , -

    : -

    . C(6; 3) -

    ,

    , C(43; 3) -

    . , $10,

    C(6; 3) C(43; 3) = 6!3! 3!

    43!40! 3!

    = 246 820:

    |

    , . .

    246 820

    13 983 816

    157

    0; 018:

    4

    . | . .

  • 6.2. 127

    6.7. , , -

    .

    12 ?

    () , ;

    () , ;

    () , , ?

    .

    C(12; 5) =

    12!

    7! 5!

    = 792

    .

    () , -

    -

    .

    C(10; 3) =

    10!

    7! 3!

    = 120

    . , 120

    .

    () ,

    .

    C(10; 5) =

    10!

    5! 5!

    = 252

    , ,

    .

    ()

    , , .

    C(10; 4). ,

    . , 2C(10; 4) , , .

    , -

    792

    : (), () (). ,

    , ,

    792 120 252 = 420:

  • 128 6.

    6.3.

    C(n; k)

    (a+ b)

    n

    . ,

    (a+ b)

    3

    = (a+ b)(a+ b)(a+ b) =

    = aaa+ aab+ aba+ abb+ baa+ bab+ bba+ bbb =

    = a

    3

    + 3a

    2

    b+ 3ab

    2

    + b

    3

    :

    , -

    , , -

    . , ,

    a b.

    , C(3; 2) = 3

    , b ( a).

    -

    : C(3; 0) = 1, C(3; 1) = 3, C(3; 2) = 3 C(3; 3) = 1.

    C(n; k),

    , , 0! = 1.

    , -

    .

    , (a + b)

    n

    ,

    a

    nkb

    k

    ( k

    0 n) b, k , a,

    (n k) . C(n; k) k n, C(n; k)

    a

    nkb

    k

    k = 0; 1; : : : ; n. ,

    (a+ b)

    n

    = C(n; 0)a

    n

    +C(n; 1)a

    n1b+C(n; 2)a

    n2b

    2

    + +C(n; n)bn: . -

    C(n; k) .

    -

    (. . 6.1).

    C(0; 0)

    C(1; 0) C(1; 1)

    C(2; 0) C(2; 1) C(2; 2)

    C(3; 0) C(3; 1) C(3; 2) C(3; 3)

    C(4; 0) C(4; 1) C(4; 2) C(4; 3) C(4; 4)

    C(5; 0) C(5; 1) C(5; 2) C(5; 3) C(5; 4) C(5; 5)

    : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : :

    C(n; 0) C(n; 1) : : : : : : : : : : : : : : : C(n; n 1) C(n; n)

    6.1.

  • 6.3. 129

    (n + 1)- -

    ,

    (a+ b)

    n

    .

    -

    ,

    1

    1 1

    1 2 1

    1 3 3 1

    1 4 6 4 1

    1 5 10 10 5 1

    ::: ::: ::: ::: ::: :::