Its just M A T H
Functions:
sigma(uL, lL, op, incVal); - Performs the sigma notation uL = upper limit, number lL = lower limit, number op = operation, string: "+" for addition, "-" for subtraction, "/" for division, "*" for multiplication, "^" for squaring incVal = value to increase by, number, set to string "lL" to make it increment intself each iteration.