{UP}
C>=Ref(Mov(C,3,S),-3) AND
(Mov( CLOSE, 8.3896, E) - Mov( CLOSE, 17.5185, E))>=
(PREV+(0.199*((Mov( CLOSE, 8.3896, E) - Mov( CLOSE, 17.5185, E))-PREV))) AND
(Mov( CLOSE, 8.3896, E) - Mov( CLOSE, 17.5185, E))>=
Ref((Mov( CLOSE, 8.3896, E) - Mov( CLOSE, 17.5185, E)),-1)

{DOWN};
C<=Ref(Mov(C,3,S),-3) AND
(Mov( CLOSE, 8.3896, E) - Mov( CLOSE, 17.5185, E))<=
(PREV+(0.199*((Mov( CLOSE, 8.3896, E) - Mov( CLOSE, 17.5185, E))-PREV))) AND
(Mov( CLOSE, 8.3896, E) - Mov( CLOSE, 17.5185, E))<=
Ref((Mov( CLOSE, 8.3896, E) - Mov( CLOSE, 17.5185, E)),-1){jimt};

MOV就是移動平均線，最后是E的話是EMA的意思，是S的話是SMA的意思，這個是確定的

PREV是類似公式重復(fù)計算前一根的意思

PREV
The PREV constant allows you to create self-referencing formulas.  A self referencing formula is one that is able to reference the "previous" period's value of itself.
For example, the following is an example of a self referencing formula:
((H+L+C)/3) + PREV
This simple formula divides the high, low, and closing prices by 3 and then adds this value to yesterday's value of the ((H+L+C)/3).
The calculation of the popular indicator On Balance Volume illustrates the use of the PREV function.

(if(c>ref(c,-1),1,-1)*volume)+PREV
Although On Balance Volume can be calculated without the use of the PREV function, an exponential moving average cannot (other than using the mov() function).  The following formula shows how a 18% exponential moving average (approximately 10-periods) is calculated using the PREV function.
(close*0.18)+(PREV*0.82)