8 8.1 () G 1 G 2 G 1 G 2 8.1 2 u 1 v 1 u 2 G 1 G 2 v 2 w 2 x w 1 x 2 1 8.1: ( ) 8.1 G 1 G 2 G 1 {u 1,v 1,w 1,x 1 } G 2 {u 2,v 2,w 2,x 2 } ( 2 u 1 v 1 u 1 v 1 ) u 1 v 1 u 2 v 2 u 1 w 1 u 2 w 2 u 1 x 1 u 2 x 2 v 1 w 1 v 2 w 2 v 1 x 1 v 2 x 2 w 1 x 1 w 2 x 2 19 8.2 plnrity 20 u 1 v 1 u 1 G 1 G 2 v 1 u 2 v 2 w 1 x 1 w 1 x 1 w 2 x2 8.2: 19 20 http://plnrity.net/ 65
21 22 8.3 2 2 6 7 d e 1 4 3 5 10 9 8 f g h i j (i) (ii) 8.3: (1) (i) (ii) (2) 1,, 10,,,j (3) 1 2 3 1 3 5 7 9 4 5 6 7 8 9 (i) 2 4 6 8 (ii) 8.4: {1, 2, 3, 4, 5, 6, 7, 8, 9} {12, 23, 14, 25, 36, 45, 56, 47, 58, 69, 78, 89} 8.4(i) (ii) ij i j 21 22 66
8.4 18 8.5 3 8.5: 19 ( ) 8.2 loop 8.6: 8.6 8.7 3 120 8.7 2 2 4 8.8 ( ) 67
8.7: 3 8.8: 4 20 8.9 1 3 5 1 2 3 4 8.9: 68
8.3 8.10 (i) (ii) (iii) 8.10: 8.10 (i) (ii) (iii) 8.11 G 1 2 1 3 1 1 3 2 2 3 3 2 0 (i) (ii) (iii) 8.11: 23 8.10 23 69
8.10 3 8.10 (i) (ii) (iii) 8.3.1 ( ) 8.12 8.12: 8.11 8.11 (i) (ii) (iii) G r G r- (r-regulr grph) 24 8.13 3-4- 24 70
3-4- 8.13: 21 2-3-4-5- 5 3-5 3-8.3.1 25 (1) 2.2 (2) 3 n K n K (Kurtowski) 8.14 K 1 K 5 (K 4 ) K 6,K 7,K 8 K n K n 25 (1) (2) (3) (4) (5) 71
K1 K2 K3 K4 K5 8.4 (sugrph) 8.14: G G 8.15: 8.15 G ( ) G G K 3 8.16 K 3 8.17 8.18 8.5 22 72
8.16: K 3 8.17: 73
d 8.18: 8.19: 74
23 ( ) 75
8.20: 76