transformations and their inverses

[ninbrm]

Replace:
(t::ExpMinusAlpha)(x::Number) = exp(-x / t.alpha)
with:
(t::ExpMinusAlpha)(x::Number) = exp(-x * t.alpha)

Inverse of ExpMinusAlpha is:
Base.inv(t::ExpMinusAlpha) = AlphaMinusLog(t.alpha)
(t::AlphaMinusLog)(x::Number) = (1/t.alpha) * -log(x)

(t::MinusLogAlpha)(x::Number) = -log(x * t.alpha)
Inverse of MinusLogAlpha is:
Base.inv(t::MinusLogAlpha) = AlphaExpMinus(t.alpha)
(t::AlphaExpMinus)(x::Number) = (1/t.alpha) * exp(-x)