% ----------------------------------------------------------------------

% diagn:
%   The author has recently reworked this---what is it? plan? outline?
%   stub? temporary appendix?---and has left it thereby in a long-term
%   form.  It wants therefore a close review.

\chapter*{Plan}
\label{stub}
\setcounter{footnote}{0}

{%
  \newcounter{enumt}
  \setcounter{enumt}{\thechapter}
  \index{gamma function}
  \index{cylinder function}
  \index{Legendre polynomial}
  \index{polynomial!Legendre}
  \index{improvement of convergence}
  \index{convergence!improvement of}
  \index{conjugate-gradient algorithm}
  \index{algorithm!conjugate-gradient}
  \index{Euler-Mascheroni constant}
  Future revisions of the book tentatively plan to add the following
  chapters.
  \begin{enumerate}
    \setcounter{enumi}{\theenumt}
    \item \label{gamma}
      The gamma function
    \item \label{bessel}
      Cylinder functions
    \item \label{orthp}
      Legendre polynomials
    \item \label{xssc}
      Acceleration of convergence
    \item \label{cgrad}
      The conjugate-gradient algorithm
    \setcounter{enumt}{\theenumi}
  \end{enumerate}%
  Future revisions also tentatively plan to develop a method to
  calculate the Euler-Mascheroni constant, but that method
  is not expected to require a chapter of its own.  It should fit in
  one of the other chapters.%
  %One would also like the book to treat a few further matters, such as
  %Kepler's laws, but it is unclear how the book should fit some of these
  %into its overall plan.  A satisfactory presentation of Kepler's laws for
  %example would want to be preceded by introductions to tensors,
  %Hamiltonian mechanics and/or conic sections---which together could
  %almost fill another book of their own.  It would also point the way
  %toward orbital mechanics, an exotic discipline that could fill
  %yet a third book (and that the author lacks expertise to treat).  A
  %less satisfactory presentation could perhaps be given, but the outer
  %limits of scope of such a book as this are somewhat arbitrary,
  %anyway.
}

