求選股公式～選擇今日包括在內往前連續下跌三天，且其中至少有壹天收盤出現跌幅大於三個點。

k1:=c<ref(c,1) and ref(c,1)<ref(c,2) and ref(c,2)<ref(c,3);

k2:=c<ref(c,1)*0.97 ;

k3:=ref(c,1)<ref(c,2)*0.97 ;

k4:=ref(c,2)<ref(c,3)*0.97;

k5:=k1 and k2;

k6:=k1 and k3;

k7:=k1 and k4;

k:k5 or k6 or k7;