Formulas:
Top[i] = Simple Moving average (Price, Length) + Dev,
Bottom[i] = Simple Moving average (Price, Length) - Dev,
MA[i] = Simple moving average (Price, MA_Length),
Mirror[i] = 2*Simple Moving average (Price, Length) - MA[i], where
Dev = Deviation*Sqrt(Sum/Length),
Sum - sum(Price[pos-i]-Simple Moving average (Price, Length)).
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