Natural Logarithm of e is 1

Theorem

 * $\ln e = 1$

where $\ln$ is the natural logarithm, $e$ is Euler's number, and $1$ is the identity element of multiplication.

Proof
The definition of the Euler's number as the Base of Logarithm will be used.

Then the result follows directly.

Also see

 * Equivalence of Definitions of Euler's Number for other definitions of Euler's number