% LaTeX Document style option "doublespace"
% -- usage:  \documentstyle[...,doublespace,...]{...}
%
% This style option produces a double-spaced document by redefining
% the LaTeX parameter \baselinestretch to 2.
%
% It also fixes a number of problems with standard LaTeX, as follows:
%
% 1. A new environment "singlespace" is provided, within which single
%    spacing will apply.
%    JFL - changed so that it works in regular text and so that vertical
%    space is before and after is correctly computed
% 2. Double spacing is turned off within footnotes and floats (figures
%    and tables).
% 3. Proper double spacing happens below tabular environments and in other
%    places where LaTeX uses a strut.
% 4. Slightly more space is inserted before footnotes.
% 5. JFL - fixes spacing before and after displayed math
%
% Note: This version sets a baselinestretch of 2. If this is too much,
%    put  \setstretch{1.7}  (or some appropriate value) before the
%    \begin{document} command. To print the document with single spacing
%    again, without removing "singlespace" environments, just put a
%    \setstretch{1} at the top of the document.
%
% PLEASE REPORT ANY BUGS
%
% Bug corrected by: Jose Alberto Fernandez   (Nov 25, 1992)
%			   alberto@cs.umd.edu
%	The style had problems running in LaTex under Tex 3
%	since at some point it executes a:
%		\endgroup .... \begingroup
%	which forgets the name of the environment you were in.
%	TeX 3 is much more sensitive to this.
%	Corrected by setting the write environment name after
%	the \begingroup is executed.
%
% Modified by: Jean-Francois Lamy
%                          lamy@ai.toronto.edu
%                          lamy@utai.uucp
%
% Author: Stephen Page  -- sdpage@prg.oxford.ac.uk
%                          sdpage%prg.oxford.ac.uk@cs.ucl.ac.uk
%
% Release date: 6 July 1986 - September 3, 1986
% Modified: November 25, 1992.
%
% Known bugs:
%    . It might be nice if spacing before the footnote rule (\footins)
%      were provided in a tidier way.
%    . Increasing struts may possibly cause some other obscure part of
%      formatting to fall over.
%    . \begin{singlespace}\begin{quote} produces the wrong spacing before
%      the quote (extra glue is inserted).
%    . shouldn't @setsize stretch parskip as well?
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%---Set up double spacing

\def\baselinestretch{2}


%---New command "\setstretch" (slightly more mnemonic... and easier to type)

\def\setstretch#1{\renewcommand{\baselinestretch}{#1}}

%---Stretch the baseline BEFORE calculating the strut size. This improves
%   spacing below tabular environments etc., probably...
%   Comments are welcomed.

\def\@setsize#1#2#3#4{\@nomath#1%
   \let\@currsize#1\baselineskip
   #2\baselineskip\baselinestretch\baselineskip
   \parskip\baselinestretch\parskip
   \setbox\strutbox\hbox{\vrule height.7\baselineskip
      depth.3\baselineskip width\z@}%
   \normalbaselineskip\baselineskip#3#4}


%---Increase the space between last line of text and footnote rule.
%   This is a very untidy way to do it!

\skip\footins 20pt plus4pt minus4pt


%---Reset baselinestretch within footnotes and floats. Originally stolen
%   from Stanford thesis style.

\def\@xfloat#1[#2]{\ifhmode \@bsphack\@floatpenalty -\@Mii\else
   \@floatpenalty-\@Miii\fi\def\@captype{#1}\ifinner
      \@parmoderr\@floatpenalty\z@
    \else\@next\@currbox\@freelist{\@tempcnta\csname ftype@#1\endcsname
       \multiply\@tempcnta\@xxxii\advance\@tempcnta\sixt@@n
       \@tfor \@tempa :=#2\do
                        {\if\@tempa h\advance\@tempcnta \@ne\fi
                         \if\@tempa t\advance\@tempcnta \tw@\fi
                         \if\@tempa b\advance\@tempcnta 4\relax\fi
                         \if\@tempa p\advance\@tempcnta 8\relax\fi
         }\global\count\@currbox\@tempcnta}\@fltovf\fi
    \global\setbox\@currbox\vbox\bgroup 
    \def\baselinestretch{1}\small\normalsize
    \boxmaxdepth\z@
    \hsize\columnwidth \@parboxrestore}
\long\def\@footnotetext#1{\insert\footins{\def\baselinestretch{1}\footnotesize
    \interlinepenalty\interfootnotelinepenalty 
    \splittopskip\footnotesep
    \splitmaxdepth \dp\strutbox \floatingpenalty \@MM
    \hsize\columnwidth \@parboxrestore
   \edef\@currentlabel{\csname p@footnote\endcsname\@thefnmark}\@makefntext
    {\rule{\z@}{\footnotesep}\ignorespaces
      #1\strut}}}

% Stolen from MIT.
%
% A single spaced quote (say) is done by surrounding singlespace with quote.
%
\def\singlespace{%
\vskip\parskip%
\vskip\baselineskip%
\def\baselinestretch{1}%
\ifx\@currsize\normalsize\@normalsize\else\@currsize\fi%
\vskip-\parskip%
\vskip-\baselineskip%
}

\def\endsinglespace{\par}

%  spacing, doublespace and onehalfspace all are meant to INCREASE the
%  spacing (i.e. calling onehalfspace from within doublespace will not
%  produce a graceful transition between spacings)
%
\def\spacing#1{\par%
 \def\baselinestretch{#1}%
 \ifx\@currsize\normalsize\@normalsize\else\@currsize\fi}

\def\endspacing{\par%
 \vskip \parskip%
 \vskip \baselineskip%
% JAF: The following macro executes its arguments in the outter environment
% and reenters without forgetting the name of the original environment.
 \edef\@tempa##1{\endgroup ##1\begingroup%
                 \def\noexpand\@currenvir{\@currenvir}}%
 \@tempa{\vskip -\parskip \vskip -\baselineskip}}

\def\onehalfspace{\spacing{1.5}}
\let\endonehalfspace=\endspacing

\def\doublespace{\spacing{2}}
\let\enddoublespace=\endspacing

% Fix up spacing before and after displayed math
% (arraystretch seems to do a fine job for inside LaTeX displayed math,
% since array and eqnarray seem to be affected as expected)
% Changing \baselinestretch and doing a font change also works if done here,
% but then you have to change @setsize to remove the call to @nomath)
%
\everydisplay{
   \abovedisplayskip \baselinestretch\abovedisplayskip%
   \belowdisplayskip \abovedisplayskip%
   \abovedisplayshortskip \baselinestretch\abovedisplayshortskip%
   \belowdisplayshortskip  \baselinestretch\belowdisplayshortskip}
--
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:| o   o | Dept. of Computer Sc.    | BITNET: alberto@cs.umd.edu
:|   ^   | University of Maryland   | UUCP: {...}!mimsy!alberto
:\  \_/  / College Park, MD 20742   |