. G ( H Í G), :
) V (H) Í V (G);
) E (H) Í E (G).
. G, G
V (H) = V (G).
. 4 G . H 3 .
.4.
. H G, - H G. , G , H.
. ϳ G (U) G (V) , G (V), 璺 - U.
. 4 H 1 G ( e (2, 4)), H 2 G.
. dz , a Î V, , G (V), a .
㳺 .
. H , ( H) , G, H:
.
. H 1 H 2 - G. H = H 1 È H 2 (ᒺ ) G, , H 1 H 2.
. H 1 H 2 - G. H = H 1 Ç H 2 () G, , H 1 H 2 .
. H 1 H 2 G , H = H 1 È H 2 . H 1 H 2 , .
: - .
,
G - .
. G S = {, e 0, e 1, , en, } ei - 1 ei ,
e 0 = (v 0, v 1)
e 1 = (v 1, v 2)
e 2 = (v 2, v 3)
...
en = (vn, vn + 1).
. S , e 0, v 0 S; en - 1, vn - . vi ei - 1 ei, .
. S , ; S ( ), -; -. S v 0 vn,
S = S (v 0, vn)
( S - n, 璺 v 0 vn).
. v 0 = vn, .
. vi vj - S,
S (vi, vj) = (ei, , ei + 1, , ej - 1)
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.5 S = (e 1, e 2, e 3, e 4, e 5) , 5, v 1 v 5. S = (e 2, e 3, e 4) .
.5
. , . .
. , . ( ) v 0 , , v 0 .
, .
() ( ), ().
G - .
. a b G , S (a, b).
S (a, b) vi , S (vi, vi), S (a, b), vi . vi, : , , .
. G , - .
G (Vi) G (V) .
, :
) v ;
) a b ( S (a, b)), b ( S (b, a));
) b ( S 1(a, b)) b ( S 2(b, c)), (S 1(a, b) + S 2(b, c)), a c .
, G , :
, ( )
,
. .
.