%ROBMACRO.TEX
\def\ni{\ \\ \noindent}
\def\tab{\makebox[.25in]{}}
\def\stab{\makebox[4ex]{}}
\def\tech#1{\medskip\ni\tab\tab\parbox{4in}{\scriptsize{#1}}\medskip}
\def\ttech#1{\ni\tab\tab\tab\parbox{3.75in}{\scriptsize{\stab#1}}}
\def\tttech#1{\ni\tab\parbox{3.5in}{\scriptsize{\stab#1}}}
\def\ttttech#1{\ni\tab\parbox{3.25in}{\scriptsize{\stab#1}}}
\def\TTech#1{\ni\\tab\tab\tab\parbox{3.75in}{\scriptsize{#1}}}
\def\TTTech#1{\ni\tab\parbox{3.5in}{\scriptsize{#1}}}
\def\TTTTech#1{\ni\tab\parbox{3.25in}{\scriptsize{#1}}}
\def\ptech#1{\ni\mbox{\ \smallskip\tab\tab\parbox{3.5in}{\scriptsize{#1}}}\\}

\def\oo{\infty}
\def\R#1{\mbox{${\rm I \! \rm R}^{#1}$}}
\def\Re#1{\mbox{${\rm I \! \rm R}^{#1}$}}
\def\C#1{\hbox{${\rm C}\llap{\vrule height1.45ex width0.15ex depth-.11ex \hphantom{t}\vphantom{l}}^{#1}$} }
\def\Z{\hbox{${\rm Z \kern 0.3ex \llap{Z}}$}} 
\def\N{\hbox{${\rm I \! \rm N}$} }
%\def\H{\hbox{${\rm I \! \rm H}$} }% Quaternions
\def\Q{\hbox{${\rm Q}\llap{\vrule height1.45ex width0.15ex depth-.11ex \phantom{\em d}}$} }
\def\hook{\hbox{$\/\vrule height0.15ex width1ex depth0ex \vrule height1.2ex width0.15ex depth0ex \,$}}
\def\therefore{\hbox{.\raise1ex\hbox{.}. }}
\def\since{\hbox{\raise1ex\hbox{.}.\raise1ex\hbox{.} }}
\def\QED{\hfill\hbox{\vrule height.8em width.7ex depth.2em $\,$}\\}
\def\qed{\hfill\hbox{[]}\\}
\def\eg{{\it e.g.${~}$}}
\def\ie{{\it i.e.${~}$}}
\def\nb{{\it N.B.${~}$}}
\def\p{\partial}
\def\dd#1{\frac{d}{d #1}}
\def\pdd#1{\frac{\partial}{\partial #1}}
\def\d{\hbox{\bf d}}
\def\ket#1{|\, #1\, \rangle}
\def\bra#1{\langle\, #1\, |}
\def\ip#1#2{\langle\, #1\, |\, #2\, \rangle}  %\IP\psi\phi
\def\map#1{\stackrel{#1}{\rightarrow}}
\def\to{\rightarrow}
\def\implies{\Longrightarrow}
\def\ideq{\equiv}
\def\less{\backslash}
\def\grad{\nabla}
\def\ab{_{ab}}
\def\Scri#1{\hbox{$\boldmath {}_{\grave{\phantom{i}}}\!\!\iota\kern -0.3ex \ell\llap{\vrule height0.85ex width0.55ex depth-0.7ex \kern 1.1ex}^{#1}\!\!$} }
\def\H#1#2{\mbox{$H^#1(#2)$}}% Cauchy horizon
\def\I#1#2{\mbox{$I^#1(#2)$}}% Future/Past
\def\J#1#2{\mbox{$J^#1(#2)$}}% Causal Future/Past
\def\D#1#2{\mbox{$D^#1(#2)$}}% Domain of Dependence
\def\Lie#1{\hbox{$\int_{\!\!\!\sim{#1}}$}}
\def\lie#1{\hbox{$\pounds_{#1}$}}%LaTeX
\def\interior#1{\hbox{$\buildrel{{}_\circ}\over{#1}$}}
\def\bdy#1{\hbox{$\buildrel{{}_\bullet}\over{#1}$}}

\def\tilde{\widetilde}     % define tilde to always be the ``widetilde''
\def\bar{\overline}     % define bar to always be wide bar
     % These are for ``less than or of the order of'' and ``greater than ...'':
\def\lto { {\raise1pt\hbox{$<$}} \!\!\!\! {\lower4pt\hbox{$\sim$}} }
\def\gto { {\raise1pt\hbox{$>$}} \!\!\!\! {\lower4pt\hbox{$\sim$}} }
             % these are alternate versions of the same symbols
             % which align the two-subsymbols better horizontally but don't
             % give quite as good vertical spacing :
% \def\lto {{\lower4pt\hbox{$\buildrel<\over\sim$}}}
% \def\gto {{\lower4pt\hbox{$\buildrel>\over\sim$}}}
             % for a still better general method see arvinds  "stacksymbol"
             %  below

\def\prop#1#2{\ni{\bf #1}$\;$ \begin{minipage}[t]{4.125in}{\em #2}\end{minipage}\bigskip}
\def\bull#1{$\bullet\;$\begin{minipage}[t]{4.125in}{#1}\end{minipage}\bigskip}
\def\proof#1{\begin{minipage}[t]{4.25in}{{\bf Proof:\ }#1}\end{minipage}\bigskip}

