%
% dmathtab.sty        ver 1.0         92/03/24
%
%  following environment is defined
%
%  \begin{\Dmathtab}   \end{\Dmathtab}
%  \begin{\Deqntab}    \end{\Dmathtab}
%
%               \=      ;   tabset    
%               \>      ;   tab right 
%               \\      ;   next line 
%               \Dkill  ;   kill line 
%
\def\Dmathtab{\refstepcounter{equation}
     \lineskip\z@\let\>\@DMrtab\let\<\@ltab\let\=\@DMsettab
     \let\+\@tabplus\let\-\@tabminus\let\`\@tabrj\let\'\@tablab
     \let\\=\@DMtabcr \global\@hightab\@firsttab
     \global\@nxttabmar\@firsttab \dimen\@firsttab\@totalleftmargin
     \global\@tabpush0 \global\@rjfieldfalse \trivlist
     \item[]\if@minipage\else\vskip\parskip\fi
     \setbox\@tabfbox\hbox{\rlap{\indent\hskip\@totalleftmargin
     \the\everypar}}%
     \def\@itemfudge{\box\@tabfbox}\@startline\ignorespaces%
     $\displaystyle\hskip\leftmargini}
%
\def\endDmathtab{$\@stopline\ifnum\@tabpush > 0 \@badpoptabs \fi%
     \endtrivlist\vskip \topsep}
%     
\let\Deqntab\Dmathtab
\def\endDeqntab{$\@DMtabeqn\@stopline\ifnum\@tabpush > 0 \@badpoptabs\fi%
     \endtrivlist\vskip \topsep}
%     
\def\@DMsettab{$\@stopfield\@addfield\ifnum \@curtab <
     \@maxtab \global\advance\@curtab \@ne \else\@latexerr{Tab
     overflow}\@ehd\fi \ifnum\@curtab > \@hightab \@hightab\@curtab\fi
     \dimen\@curtab\dimen\@curtabmar
      \advance\dimen\@curtab \wd\@curline\@startfield\ignorespaces%
      $\displaystyle}

\def\@DMrtab{$\@stopfield\@addfield\ifnum \@curtab<\@hightab
      \global\advance\@curtab \@ne \else\@badtab\fi
      \@tempdima\dimen\@curtab
      \advance\@tempdima -\dimen\@curtabmar
      \advance\@tempdima -\wd\@curline
      \global\setbox\@curline\hbox{\unhbox\@curline\hskip\@tempdima}
      \@startfield\ignorespaces%
      $\displaystyle}

\def\@DMtabcr{$\@stopline \@ifstar{\penalty \@M \@DMxtabcr}{\@DMxtabcr}%
             $\displaystyle\hskip\leftmargini}

\def\@DMxtabcr{\@ifnextchar[{\@itabcr}{\vskip 2ex \@startline%
              \ignorespaces}}

\def\@DMtabeqn{\@stopfield\@addfield\global\@rjfieldtrue\@startfield%
              \ignorespaces\@eqnnum}

\def\Dkill{$\@stopfield\@startline\ignorespaces%
           $\displaystyle\hskip\leftmargini}
