请教金融工程师：均线信号问题？　[金字塔]

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ma21:ma(close,21);
ma55:ma(close,55);
ma120:ma(close,120);

if (CROSS(ma120,close) and ENTERBARS<21) or (CROSS(ma55,close) and ENTERBARS>=21 and ENTERBARS<55) or (CROSS(ma21,close) and ENTERBARS>=55) and HOLDING>0 then BEGIN
        sell(1,1,MARKETR);
END

if (CROSS(close,ma120) and ENTERBARS<21) or (CROSS(close,ma55) and ENTERBARS>=21 and ENTERBARS<55) or (CROSS(close,ma21) and ENTERBARS>=55) and HOLDING>0 then BEGIN
        sellshort(1,1,MARKETR);
END

if ma21>ma55 and ma55>ma120 and close>ma21 and holding=0  then  BEGIN
        buy(1,1,MARKETR);
END

if ma21<ma55 and ma55<ma120 and close<ma21 and holding=0  then  BEGIN
        buyshort(1,1,MARKETR);
END