请帮忙修改，提示错误

请帮忙修改，提示错误 Params Vars Series<Numeric> aa; Series<Numeric> bb; Series<Numeric> cc; Events OnBar(ArrayRef<Integer> indexs) { aa = (Open+High+Low+Close*3)/6; bb = (8*aa+7*aa(1)+6*aa(2)+5*aa(3)+4*aa(4)+3*aa(5)+2*aa(6)+aa(7))/36; cc = (Lowest(bb,2)+Lowest(bb,4)+Lowest(bb,6))/3; plotnumeric("cc",cc,0,Green); plotnumeric("cc",bb,0,red); If(MarketPosition <>1 && bb[1] > cc[1]) { Buy(0,Open); } If(MarketPosition <>-1 && bb[1] = cc[1]) { SellShort(0,Open); } }