[suggestion] for gsl_sf_Ci_e (in specfunc/sinint.c)

[Gerard Jungman]

Arvid Requate wrote:
> 
> while using the special function routine gsl_sf_Ci_e, I noticed
> that given an argument of zero it aborts with an error, while
> mathematically it should simply return zero.

Ci(x) has a logarithmic singularity at x=0. There may
be varying definitions, but the standard one has this
behaviour, as does the implementation in GSL.

Thanks.

-- 
G. Jungman