, : 1) , ; 2) , [23].
, XUC=D. (XUC)ÅD=Æ. , X:
(F1IX)U(F2I )=Æ,
F1, F2 , X.
, , :
(F1IX)=Æ (F2I )=Æ.
, :
.
F1, F2, .
, (XUC)ÅD=Æ. X , , , :
,
, .
:
.
( ). , , :
.
:
.
, :
.
:
.
, , :
.
: , .. .
, C, D.
C={2,3,6,9}, D={1,2,3,5,6,7,8,9}. (CÅD)={1,5,7,8}ÍD. X , , : X={1,2,5,7,8,9}, .. (CÅD)ÍXÍD .
C={2,3,4,6,9}, D={1,2,3,5,6,7,8,9}. (CÅD)={1,4,5,7,8} D={1,2,3,5,6,7,8,9}. !
- .
, |AUB|=|A|+|B||AIB|, .., , .. .
, |A\B|=|A||B|, , |A\B|=|A||AIB|, , .. .
, |AÅB|=|A|+|B|2|AIB|.
, . .
n (, ) ( ) ( ) , , , ( ).
|
|
, . , n(n-1)/2 .
, n=8:
(1,2),(1,3),(1,4),(1,5),(1,6),(1,7),(1,8),
(2,3),(2,4),(2,5),(2,6),(2,7),(2,8),
(3,4),(3,5),(3,6),(3,7),(3,8),
(4,5),(4,6),(4,7),(4,8),
(5,6),(5,7),(5,8),
(6,7),(6,8),(7,8) 28 : 8´7/2=28=7+6+5+4+3+2+1. .
n=100, , 4,95 . , n=100000 ( ), 1999950 , .. 1389 ! . . , , .
. , , . . , . . - . , .
.
, , [24].
, , , , . , , .
, , . .
() , [24].
.
, n . , n ||=n. .
1,...,k , .. iIj=Æ, i¹j.
,
.
. k=2 . n , y Y, m , y n+m .
k=2 . n y m , (,y) n×m .
|
|
, :{x1,x2}, Y:{y1,y2}.
(x,y)
X×Y={(x1,y1),(x1,y2),(x2,y1),(x2,y2)}.
k (1,2,...,k) n1n2...nk , ni i- i, i 1 k (: ).
, ni , , , , , .. k, nk.
i1,...,xik ={x1,...,xn} () () k n , , (n,k) .
, . , , .
, .
, .. .
(n,k) , , (n,k) .
n k k, n .
n k k n- , (- Assing ) :
=nk.
, k n , n ..: n×n×...×n=nk.
. ?
(3,2), 2, 3- ={t1,t2,t3}. 3 2:
.
:
1) (t1,t1); 2) (t1,t2); 3) (t1,t3);
4) (t2,t2); 5) (t2,t3); 6) (t2,t1);
7) (t3,t3); 8) (t3,t2); 9) (t3,t1).
3- , .. 2.
. , , , (t1,t2), (t2,t1) , ( , ..). : (t1,t1), (t2,t2), (t3,t3).
k n .
(n,k) , (n,k) (n,k) .
.
(n,k) k, n . n , n-1 .., k- n-(k-1) :
=(n-1)(n-2)...[n-(k-1)].
, 1×2×××(n-k):
, k=0 . , k>n =0.
. 3- ?
, (K={1,2,3}), .. 3 2, :
.
, , , , -, :
|
|
(1,2), (1,3), (2,1), (2,3), (3,1), (3,2).
, ( ), .
. 10 3 ? .
10 3, :
.
n ( n, n ). , , n . n Pn. , , n n:
, 0!=1.
. ?
, .. 3=3!=6.
:
(1,2,3), (1,3,2), (2,3,1), (2,1,3), (3,1,2), (3,2,1).
. -, 5, 1,2,3,4,5 ?
5=5!=120 -, 5. 5? 5 , 5 . 5 , 1,2,3,4 4=4!=24 . , 1,2,3,4,5 5 120-24=96.
, , .
[23].
: , 010, .. k=3 2- ={0,1}, .
, 1, 2, 3. 3=3!=6 . :
, , 0 (1,3). , (2!) (1,3), (3,1) , .. , .
.
, , , ?
6=6!=720 , . ? , , , , . . , 720 , 720/4=180 . , , , .
|
|
, n ={x1,x2,...,xn} V k, i- ki, V, S=(k1,k2,...,kn), .
, ={0,1,2,3} V=(010223), : S=(2,1,2,1).
, , .
(k1,k2,...,kn)= .
. 102202030?
, {0,1,2,3} (1,4,3,1),
(1,4,3,1)= .
k- n . , .. .
.
n k k, n .
n k, , , ( ) , k :
.
. , . ={1,2,3}:
{1,2},{1,3},{2,3}.
3- 2:
.
2! , , 2=2! .
. 3 5 ?
5 3 : =5×4×3=60.
, , (,b,) (b,,) . 3=3!=6 , 3
.
k n . - n k.
, 3 2 . , 3 2 , .
2 3:
(m1,m1,m1),(m1,m2,m2),(m1,m1,m2),(m2,m2,m2),
m .
, , , , , , .. .
[24].
2 3 n+k-1=2+3-1=4, 3 n-1=1 :
1- | 2- | ||
000 | 1 | (m1,m1,m1) | |
0 | 1 | 00 | (m1,m2,m2) |
00 | 1 | 0 | (m1,m1,m2) |
1 | 000 | (m2,m2,m2) |
, , ( ), .. (3,1)= =4.
,
,
.
, 6 4 .
4- 6:
.
.
|
|
. .
. 6, .
6
k n | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
0 | 1 | ||||||||
1 | 1 | 1 | |||||||
2 | 1 | 2 | 1 | ||||||
3 | 1 | 3 | 3 | 1 | |||||
4 | 1 | 4 | 6 | 4 | 1 | ||||
5 | 1 | 5 | 10 | 10 | 5 | 1 | |||
6 | 1 | 6 | 15 | 20 | 15 | 6 | 1 | ||
7 | 1 | 7 | 21 | 35 | 35 | 21 | 7 | 1 | |
8 | 1 | 8 | 28 | 56 | 70 | 56 | 28 | 8 | 1 |
, .
, . [26]: (. 10).
. 10.
, , , . :
( )
( n! )
.
1)
, , .
2)
, ,
, b .
:
.
. :
1) , n, , n=1. , n=2,3,4. , n=1.
2) . , n, , n+1.
3) 1 2 , n.
.
n+1. , a+b:
:
, :
.
(1): i i-1.
, .. , (1). . n- ( n): , , :
, , , , , : , , , :
.
, n.
1 n :
2: .
, :
. , .
n=1 1+x, .. ( 1), ( x).
n=2 (1+x)2=1+2x+x2, .. ..