%%
%% A collection of useful commands
%%

%% can call commands even when they are not defined
\def\safe#1{
  \ifdefined#1
    #1
  \else
    {\color{red}\bf?}
  \fi
}


%% larger skip
\newskip\hugeskipamount
  \hugeskipamount=24pt plus8pt minus8pt
\def\hugeskip{\vskip\hugeskipamount}


%% stack relations in subscript or superscript
\def\mAthop#1{\displaystyle\mathop{\scriptstyle #1}}

%% array spanning the entire line
\newlength\largearray@width
\setlength\largearray@width\textwidth
\addtolength\largearray@width{-10pt}
\def\largearray{\begin{array}{@{}>{\displaystyle}l@{}}\hphantom{\hspace{\largearray@width}}\\[-.5cm]}
\def\endlargearray{\end{array}}

%% qedsquare
\def\qed{\penalty10000\hfill\penalty10000$\square$}