%-*-tex-*-
%boxexample
\def\wid{{\tt wd}}
\def\hei{{\tt ht}}
\def\dpt{{\tt dp}}
\def\boxpoint{\setbox2=\hbox{\vrule width 8pt height 3pt depth 5pt} \wd2 =0pt
\ht2=0pt \dp2=0pt \hskip -8pt \box2}
\setbox4=\hbox{\hei}
\def\vbrule{\vrule width 1pt}
\def\hbrule{\hrule height 1pt}
\setbox0=\hbox to 1.2in{\vbrule$\longleftarrow \hss \wid \hss\longrightarrow$\vbrule}
\setbox8=\vbox to 2in{\offinterlineskip\hbox to \wd4{\hss$\uparrow$\hss}
\hbox to \wd4{\hss $\Bigg\vert$\hss}\vss
\hbox to \wd4{\hss \hei\hss}\vss
\hbox to \wd4{\hss $\Bigg\vert$\hss}
\hbox to \wd4{\hss$\downarrow$\hss}}
\setbox6=\vbox{\hbox to \wd4{\hss$\uparrow$\hss}
\hbox to \wd4{\hss \dpt\hss}
\hbox to \wd4{\hss$\downarrow$\hss}}
\def\boxexample{\bigbreak\line{\hss
\vtop{\copy0 \offinterlineskip
\smallskip
\hbrule
\hbox to \wd0{\vbrule height \ht8
\boxpoint \hss
\hskip 4pt\copy8 \hss
\vbrule height \ht8}
\hbrule
\hbox to \wd0{\vbrule height \ht6 \hss
\copy6 \hss
\vbrule height \ht6}
\hbrule
}
\vtop{\hrule height 0pt
\vskip 1in
\hbox{\qquad \vrule height 6pt width 8pt depth 2pt
\quad $\Leftarrow$ Reference Point}
\vskip 62pt
\hbox{$\Leftarrow$ Baseline}}
\hss}\medskip}