Revert 0b4e7b9..6e90df4

This rolls back to commit 0b4e7b91f162b478c9a5285bc5fad9acbab0b681.
Solver more robust

Numeric solver now tries solving L = R, log(L) = log(R), and exp(L) =
exp(R), the latter two of which should be helpful when L and R are very
large or small, respectively. Still twiddling my thumbs on REPL.