: - , , , .
, .
.
x1x2x3x4, x1x2x4x3 x1x3x2x4 - ;
x1 x2 x4 x3 x1 - .
, .
(, ), . , .
- , .
, .
1. G(x,σ), |x|=n, xi xj ρ(xi) + ρ(xj) ≥ n-1, .
ρ(xi) + ρ(xj) ≥ n, .
2. ρ(xi)≥½|x|=n/2, .
3. ≥ 2 .
4. .
, , . , , .
a | b | c | d | e | f |
b | c | a | c | c | a |
- | e | d | f | d | b |
- | - | - | - | - | c |
.
c→a d→c , .. , . .
: (a,b,e,c,d,f) (a,b,e,d,f,c)
, .. c→a f→a.