Function: lngamma
Section: transcendental
C-Name: glngamma
Prototype: Gp
Help: lngamma(x): logarithm of the gamma function of x.
Doc: principal branch of the logarithm of the gamma
 function of $x$. This function is analytic on the complex plane with
 non-positive integers removed. Can have much larger arguments than \kbd{gamma}
 itself. The $p$-adic \kbd{lngamma} function is not implemented.
