Function: incgamc
Section: transcendental
C-Name: incgamc
Prototype: GGp
Help: incgamc(s,x): complementary incomplete gamma function.
Doc: complementary incomplete gamma function.
 The arguments $x$ and $s$ are complex numbers such that $s$ is not a pole of
 $\Gamma$ and $|x|/(|s|+1)$ is not much larger than 1 (otherwise the
 convergence is very slow). The result returned is $\int_{0}^{x}
 e^{-t}t^{s-1}\,dt$.
