[Haskell-cafe] log, exp, (**), and non-negative real numbers

[Will Yager]

If you end up coming up with a nice library design, you may want to generalize these operations from Double-valued logarithms to conversions between a Lie group and its corresponding Lie algebra. 

Exp/ln on all/positive real numbers is a special case of exp/ln on a lie algebra/group. 

Maybe worth checking if there already exists a package for working with lie groups in a nicely-typed way. If there's not a haskell one, I bet one of the theorem prover languages (coq, agda, idris) has one. 

Best,
Will