* Simplify {{{sum-an}}} so we stop the sum when the terms no longer
   contribute to the sum.
 * Change {{{big-n}}}.  This still needs work.

   converge when v = 0.
 * Clear hash tables in bessel-j.

caused oct.elliptic-pi.n2.d to fail.

 * qd-gamma.lisp::
   * Return sqrt(least-positive-normalized-double) instead of
     least-positive-normalized-double.
 * rt-tests.lisp::
   * Add test for this case.

case where v is an integer.

 * Add series for Bessel J.  (Not working yet.)

series.

qd-methods.lisp:
* Define FLOATP
* Fix bugs in FLOAT:
  * (FLOAT float nil) is an error
  * (FLOAT float) returns the float
  * (FLOAT rational) returns a single-float.

qd-package.lisp:
o Export FLOATP, shadowing CL:FLOAT.

rt-tests.lisp:
o Add a few tests for FLOAT.

qd-methods.lisp:
o Define the macro

qd-gamma.lisp:
o Use it.

skip the first term in the series.

seems that bessel_j(n,z) mostly works.

negative values of the parameter.

* Don't let NaN's fool check-accuracy
* Add tests for exp-integral-e with v = 1.

* Allow (exp-integral-e 1 z) to work.
* psi
  * Handle psi(1) specially.
  * Do a better job with cot(%pi*z) when z is an odd multiple of 1/2
    where cot is 0.
  * Fib bug in computing the number of terms when we try to float a
    complex.  Just float the realpart.