# Using iteration in a custom study condition for a scan query?

#### cpd

##### New member
I'm interested in writing some ThinkScript code that will allow me to scan for stocks where over the last N bars, the 17EMA M bars ago is greater than the 17EMA M+1 bars ago. I'm learning ThinkScript now and started initially by manually typing out a chain of conditions as shown below. I'm wondering if I can use a fold statement to rewrite this so I can set the number of bars I look back over to any arbitrary value.
MovAvgExponential("length" = 17)."AvgExp" is greater than MovAvgExponential("length" = 17)."AvgExp" from 1 bars ago and
MovAvgExponential("length" = 17)."AvgExp" from 1 bars ago is greater than MovAvgExponential("length" = 17)."AvgExp" from 2 bars ago and
MovAvgExponential("length" = 17)."AvgExp" from 2 bars ago is greater than MovAvgExponential("length" = 17)."AvgExp" from 3 bars ago and
MovAvgExponential("length" = 17)."AvgExp" from 3 bars ago is greater than MovAvgExponential("length" = 17)."AvgExp" from 4 bars ago
Any suggestions?

Solution
You can simply do something like `def Ema = movavgexponential(close,17);` and from there you can just use `Ema > Ema[1]` and so on. You don't need to fully type it out each time. And yes, there is a way to do it using fold, but the Sum() function natively encapsulates a fold which does it for you.

Ruby:
``````input N = 4;
def Ema = movavgexponential(Close,17);
def Above = sum(Ema > Ema[1],N) == N;``````
You can simply do something like `def Ema = movavgexponential(close,17);` and from there you can just use `Ema > Ema[1]` and so on. You don't need to fully type it out each time. And yes, there is a way to do it using fold, but the Sum() function natively encapsulates a fold which does it for you.

Ruby:
``````input N = 4;
def Ema = movavgexponential(Close,17);
def Above = sum(Ema > Ema[1],N) == N;``````

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