编写条件：

编写方法：

A:=maX(MAX(MA(C,5),MA(C,13)),MA(C,21));
B:=MIN(MIN(MA(C,5),MA(C,13)),MA(C,21));
crOSS(C,MA(C,5)) AND CROSS(C,MA(C,13)) AND CROSS(C,MA(C,21)) AND C>A AND L<B;