X:=(3*C+L+O+H)/6;
多空线:=(20*X+19*REF(X,1)+18*REF(X,2)+17*REF(X,3)+16*REF(X,4)+15*REF(X,5)+14*REF(X,6)
+13*REF(X,7)+12*REF(X,8)+11*REF(X,9)+10*REF(X,10)+9*REF(X,11)+8*REF(X,12)
+7*REF(X,13)+6*REF(X,14)+5*REF(X,15)+4*REF(X,16)+3*REF(X,17)+2*REF(X,18)+
REF(X,20))/210;
选股:CROSS(C,多空线);