Problem in a strategy

[Ariel Pardo]

I have the following code(is not mine) in an Expert Advisor:

if((Handle(DXHandle, 0) - Simbolo.Ask()) >= (DXPontosDistancia * _Point)){...}

Handle(DXHandle,0) is a function that returns the value of an moving average of seven candles of one minute. DXPontosDistancia is a value that they obtained from backtesting(is 140) and _Point is the pont of the active(in this case Bra50). If that condition is true, we make a buy operation. My question is: what is the point of that substraccion? Why we substract a moving average with the Ask Price?

[William Roeder]

MA(7) - Ask >= X or MA >= Ask + X or MA - X >= Ask. Means the current Ask is X below the MA. Express it however you want.

[Ariel Pardo]

William Roeder:
MA(7) - Ask >= X or MA >= Ask + X or MA - X >= Ask. Means the current Ask is X below the MA. Express it however you want.

and that is a good sign to buy?