%% some small & useful macros by TP
\def\cbox#1{\vbox{\halign{&\hss##\hss\cr#1\crcr}}}
\def\lbox#1{\vbox{\halign{&##\hss\cr#1\crcr}}}
\def\rbox#1{\vbox{\halign{&\hss##\cr#1\crcr}}}
\def\boxit#1{\vbox{\hrule\hbox{\vrule\kern3pt
      \vbox{\kern3pt#1\kern3pt}\kern3pt\vrule}\hrule}}
\endinput
