source: Backup NB/Talks/MEMPHYSetal/SPLFrejusArt/SPLFrejus/setstack.sty@ 689

%%
%% This is file `setstack.sty', created by VIK 15 Dec 1998
%% Reproduces useful macros from amsmath.sty, thus avoiding the need to load the entire
%% amsmath.sty and run into conflicts
%% Adds definitions for \overset, \underset, \sideset, \substack, \boxed, \leftroot,
%% \uproot, \dddot, \ddddot, \varrow, \harrow (see The LateX Companion, pp 225-227)
\NeedsTeXFormat{LaTeX2e}% LaTeX 2.09 can't be used (nor non-LaTeX)
[1998/12/15]% LaTeX date must December 1998 or later
\ProvidesPackage{setstack}
\DeclareRobustCommand{\text}{%
  \ifmmode\expandafter\text@\else\expandafter\mbox\fi}
  \let\nfss@text\text
  \def\text@#1{\mathchoice
    {\textdef@\displaystyle\f@size{#1}}%
      {\textdef@\textstyle\tf@size{\firstchoice@false #1}}%
        {\textdef@\textstyle\sf@size{\firstchoice@false #1}}%
          {\textdef@\textstyle \ssf@size{\firstchoice@false #1}}%
            \check@mathfonts
}
\def\textdef@#1#2#3{\hbox{{%
             \everymath{#1}%
             \let\f@size#2\selectfont #3}}}

% adds underset, overset, sideset and 
% substack features from amsmath.sty (Companion p. 226)

\def\invalid@tag#1{\@amsmath@err{#1}{\the\tag@help}\gobble@tag}
\def\dft@tag{\invalid@tag{\string\tag\space not allowed here}}
\def\default@tag{\let\tag\dft@tag}

\def\Let@{\let\\\math@cr}
\def\restore@math@cr{\def\math@cr@@@{\cr}}

\def\overset#1#2{\binrel@{#2}%
\binrel@@{\mathop{\kern\z@#2}\limits^{#1}}}
\def\underset#1#2{\binrel@{#2}%
\binrel@@{\mathop{\kern\z@#2}\limits_{#1}}}
\def\sideset#1#2#3{%
\@mathmeasure\z@\displaystyle{#3}%
\global\setbox\@ne\vbox to\ht\z@{}\dp\@ne\dp\z@
 \setbox\tw@\box\@ne
\@mathmeasure4\displaystyle{\copy\tw@#1}%
\@mathmeasure6\displaystyle{#3\nolimits#2}%
\dimen@-\wd6 \advance\dimen@\wd4 \advance\dimen@\wd\z@
\hbox to\dimen@{}\mathop{\kern-\dimen@\box4\box6}%
}

\newenvironment{subarray}[1]{%
\vcenter\bgroup
\Let@ \restore@math@cr \default@tag
\baselineskip\fontdimen10 \scriptfont\tw@
\advance\baselineskip\fontdimen12 \scriptfont\tw@
\lineskip\thr@@\fontdimen8 \scriptfont\thr@@
\lineskiplimit\lineskip
\ialign\bgroup\ifx c#1\hfil\fi
$\m@th\scriptstyle##$\hfil\crcr
}{%
\crcr\egroup\egroup
}
\newcommand{\substack}[1]{\subarray{c}#1\endsubarray}

% definitions of dddot and ddddot(p. 225)

\def\dddot#1{{\mathop{#1}\limits^{\vbox to-1.4\ex@{\kern-\tw@\ex@
 \hbox{\normalfont ...}\vss}}}}
\def\ddddot#1{{\mathop{#1}\limits^{\vbox to-1.4\ex@{\kern-\tw@\ex@
 \hbox{\normalfont....}\vss}}}}

% definitions of leftroot, uproot (p.225)

\begingroup \catcode`\"=12
\gdef\@@sqrt#1{\radical"270370 {#1}}
\endgroup

\def\leftroot{\@amsmath@err{\Invalid@@\leftroot}\@eha}
\def\uproot{\@amsmath@err{\Invalid@@\uproot}\@eha}
\newcount\uproot@
\newcount\leftroot@
\def\root{\relaxnext@
  \DN@{\ifx\@let@token\uproot\let\next@\nextii@\else
   \ifx\@let@token\leftroot\let\next@\nextiii@\else
   \let\next@\plainroot@\fi\fi\next@}%
  \def\nextii@\uproot##1{\uproot@##1\relax\FN@\nextiv@}%
  \def\nextiv@{\ifx\@let@token\@sptoken\DN@. {\FN@\nextv@}\else
   \DN@.{\FN@\nextv@}\fi\next@.}%
  \def\nextv@{\ifx\@let@token\leftroot\let\next@\nextvi@\else
   \let\next@\plainroot@\fi\next@}%
  \def\nextvi@\leftroot##1{\leftroot@##1\relax\plainroot@}%
   \def\nextiii@\leftroot##1{\leftroot@##1\relax\FN@\nextvii@}%
  \def\nextvii@{\ifx\@let@token\@sptoken
   \DN@. {\FN@\nextviii@}\else
   \DN@.{\FN@\nextviii@}\fi\next@.}%
  \def\nextviii@{\ifx\@let@token\uproot\let\next@\nextix@\else
   \let\next@\plainroot@\fi\next@}%
  \def\nextix@\uproot##1{\uproot@##1\relax\plainroot@}%
  \bgroup\uproot@\z@\leftroot@\z@\FN@\next@}
\def\plainroot@#1\of#2{\setbox\rootbox\hbox{%
 $\m@th\scriptscriptstyle{#1}$}%
 \mathchoice{\r@@t\displaystyle{#2}}{\r@@t\textstyle{#2}}
 {\r@@t\scriptstyle{#2}}{\r@@t\scriptscriptstyle{#2}}\egroup}
\def\r@@t#1#2{\setboxz@h{$\m@th#1\@@sqrt{#2}$}%
 \dimen@\ht\z@\advance\dimen@-\dp\z@
 \setbox\@ne\hbox{$\m@th#1\mskip\uproot@ mu$}%
 \advance\dimen@ by1.667\wd\@ne
 \mkern-\leftroot@ mu\mkern5mu\raise.6\dimen@\copy\rootbox
 \mkern-10mu\mkern\leftroot@ mu\boxz@}
 
%   definition of \boxed (math in frame, no dollars) p 225

\def\boxed#1{\fbox{\m@th$\displaystyle#1$}}

% definition of \smash for top and bottom parts of expression in braces (p.227)
\renewcommand{\smash}[2][tb]{%
  \def\smash@{#1}%
  \ifmmode\@xp\mathpalette\@xp\mathsm@sh\else
        \@xp\makesm@sh\fi{#2}}

% additional difinitions for arrows 
% zero mm wide #2 mm long vertical arrow shifted 1 mm to left, 1 mm up
\newcommand{\varrow}[2]{%
\unitlength=1mm
  \begin{picture}(0,6) % (0,0)
  % - for #1 to point arrow down,+ to point arrow up
  \end{picture}%
  \put(0,6){\vector(0,#1 3){#2}}    % 6,- for down, 0, + for up
}
% 1 mm high #2 mm long horizontal arrow shifted 1 mm up (0,-1)
\newcommand{\harrow}[2]{%
\unitlength=1mm
  \begin{picture}(8,1)(0,-1) %
  % 1 mm distance between arrow and stackreled object over it (8,1)
  \put(0,0){\vector(#1 2,0){#2}}     % - to point arrow left, + right
  \end{picture}%
}

\endinput
%% end of setstack.sty
%% Corrections history:
%%