Definition:Lambert W Function

Definition
Let $e^z: \C \to \C$ be the complex exponential function.

Then $\map W z$ is defined to be the multifunction that satisfies:


 * $\map W z e^{\map W z} = z$

Also known as
The Lambert W function is also called:
 * Lambert-W function
 * Lambert W-function
 * Lambert's W function
 * The $\Omega$ (omega) function
 * The Product Log function