[Help-gsl] Numerical differentiation documentation out of date?

[Liam Healy]

The documentation for the numerical differentiation functions
gsl_deriv_central, gsl_deriv_forward, gsl_deriv_backward all show 5
arguments, e.g.
int gsl_deriv_central (const gsl_function * f, double x, double h,
double * result, double * abserr)
and explicitly mention a step variable h in the description.  However
diff/diff.h and diff/diff.c show no such argument, having only 4
total:
int gsl_diff_central (const gsl_function *f,
                      double x,
                      double *result, double *abserr);
etc.

It appears the functions were changed but the documentation was not,
because I think old versions of the library had the step as an
argument.  Can the documentation (including the description) be
updated to reflect the current function?

Thank you.

Liam