主题：如何编写公式：5分钟周期下，围绕收盘价的上下波动超过20点出交易信号

variable:n=close;

if close>n+20*mindiff and holding=0 then  begin

   buy(holding=0,1,market);

   n:=close;

end

if close<n-20*mindiff and holding=0 then begin

   buyshort(holding=0,1,market);

  n:=close;

end

variable:n=close;

if close>n+20*mindiff  then  begin
   sellshort(1,0,market);
   buy(holding=0,1,market);

   n:=close;

end

if close<n-20*mindiff  then begin
   sell(1,0,market);
   buyshort(holding=0,1,market);

  n:=close;

end