( ) 19 5 12 1 2 1 1 2 1 2 [1, 2, 3, 4] 3 4 5 3 4 5 2 ' & ( $ % : 6 [1] =⇒ : = + = − = 6 3 =⇒ : n n n − 2 = (n − 2)× n × n =( + = (n − 2)× × 7 : 7 4 “ ” 3 5 8 9 [5] 8 9 6 ( ) 4 x = (x1, x2) 0 dE(x, 0) = � x2 1 + x2 2 7 x = (x1, x2) ( 0 dP (x, 0) = 2 � x2 1 + x2 2 1 − x2 1 − x2 2 x = (x1, x2) dP (x, 0) 10 11 ( ) ( ) ( ) 12 10 11 8 13 : 12 (horo) 13 9 ⇒ ⇒ 10 14 ( = − × 15 14 15 ( 11 5 (1) (2) (3) 16