s t 1, 2,..., 10 s t a, b,..., k t s 1, 2,..., 10 1 a, b,..., k 1 s t ts 1 0 ( 2.25) ½ ¾ ½¼ x 1j = 1 x 2c = 1 x 3e = 1
. T ::= x f n t 1 t n F n,m (x(t 1 t n )t 1 t m) x, f n n, F n,m n, m-., F n,m (x(t 1 t n )t 1 t m), x, t 1,..., t n, t 1,..., t m. F n,m (x(t 1 t n )