[Bug-gsl] domain for gamma functions

[David Boersma]

Hello GSL maintainers/developers,

First: thanks for providing such a useful scientific library!

Second: I think I found a minor mistake in the manual, on the page about 
gamma functions: 
http://www.gnu.org/software/gsl/manual/html_node/Gamma-Functions.html#Gamma-Functions

On this page the valid domain for most of the functions is described with 
the phrase "subject to x not being a negative integer". However, for x=0 
these functions diverge just like for negative integers. I suppose that 
something like "subject to x-1 not being a negative integer" was intended, 
or "subject to x not being a negative integer or zero".

Cheers,
David