SolveAPowerBesideALaurentPolynomialInAnExponential​(AngouriMath.​Entity,​AngouriMath.​Entity.​Variable,​System.​Boolean)

A power of x or of a linear that is not a polynomial, beside a rational function of one exponential of a linear
e^B that is a Laurent polynomial in it: tanh(u) is (e^(2u) - 1)/(e^(2u) + 1) here, so
1/(a + a tanh(u)) is (1 + e^(-2u))/(2a), and tan(u) and cot(u) are written in
e^(2 i u) first: 1/(1 + i tan(u)) is (1 + e^(-2 i u))/2. Each term is then the power beside
an exponential of a linear, a gamma function. And beside any power of x, or none, a Laurent polynomial in an
exponential of something in x that is not linear: x sinh(a + b x^n)^2. The exponentials are whole
multiples of one, and the quotient in w = e^B has a power of w below the bar, or this declines. Rubi's
6.3.1, 6.4.1, 4.3.10, 4.4.10, 6.1.3 and 6.2.3.
https://github.com/asc-community/AngouriMath/issues/2075