h1≤0≤n2 (a)=x(n)zm+x(n,+1)za+…+x(-1)z +x(0)z°+x(1)z+…+x(n2-1)z,-D+x(n2)z% .0m→0000%>00 Roc:0<E<∞ 0≤n,≤n2 .0-”→00”→0 Roc:0<E≤∞ n1≤n2≤0 .0-”→000”-→00 Roc:0≤E<∞n n 1 2   0 1 1 ( 1) 1 1 1 ( ) ( ) ( 1) ( 1) n n X z x n z x n z x z         2 2 0 1 ( 1) 2 2 (0) (1) ( 1) ( ) n n x z x z x n z x n z           2 1 0 : 0 n n Roc z            0   n n 1 2 0 0 : 0 n n Roc z           0 0 : 0 n n Roc z           n n 1 2   0