\documentclass{ppex}
\nonstopmode

\pagestyle{empty}
\setlength\textwidth{213.0pt}
\begin{document}
\ResetPreambleCommands
\ReadyForTheFray

.PS
define rect X box width 0.5i height 0.3i X
A: rect "Class" ; move down right from A.se
B: rect "Object"; move down left
C: rect "Person"; move down left
D: rect "Male"  ; move down right from C.c
E: rect "Caller"; move down left
G: rect "Lesley"; move down left from D.c
F: rect "John"
line from 2/3 <A.sw,A.se> to B.n
line from 1/3 <A.sw,A.se>    \
       to 1/3 <C.nw,C.ne>
line dashed from B.sw        \
            to 2/3 <C.nw,C.ne>
line dashed from C.sw to D.ne
line dashed from C.se to E.nw
line from D.sw to F.n
line from E.sw to G.n
.PE
\usebox\graph
\end{document}