The indicator is similar to Bollinger Bands, but has a signal ("mirror") line.
It has four input parameters:
Interpretation of the indicator:
Enter a long position, when the MA line crosses the Mirror line upwards
Enter a short position, when the MA line crosses the Mirror line downwards

Translated from Russian by MetaQuotes Ltd.
Original code: https://www.mql5.com/ru/code/20338
SWMA
Sine-Weighted Moving Average
Lyapunov_HP
The oscillator indicator based on Lyapunov stability theory, with the Hodrick-Prescott filter