\documentstyle[12pt]{article} \oddsidemargin=18mm \evensidemargin=18mm \textwidth=135mm \topmargin=0mm \textheight=220mm \begin{document} \thispagestyle{empty} \newcommand{\hs}{\hspace*} \newcommand{\fns}{\footnotesize} \newcommand{\hugeskip}{\vspace*{10mm}\noindent} \newcommand{\N}{\sim \!\!} \newcommand{\C}{\!\rightarrow\!} \newcommand{\CC}{\,\rightarrow\,} \newcommand{\Cdot}{\,\rightarrow\!.\;} \newcommand{\K}{\;\&\;} \newcommand{\mt}{\mbox{{\fns $\wedge$}}} \newcommand{\A}{\mbox{$\,${\fns $\vee$}$\,$}} \newcommand{\fs}{\circ} \newcommand{\imp}{\:\Longrightarrow\:} \newcommand{\spt}{\raisebox{0.25ex}{$\bullet$}} \newcommand{\Leq}{\raisebox{1pt}{{\small $\;\leq\;$}}} \newcommand{\PW}{{\bf P$-$W}} \newcommand{\Df}{\:\:=\!\mbox{df}\,\:\:} \newcommand{\Mc}{M\raisebox{3pt}{c}} \newcommand{\I}{\"{\i}} \def\Dt#1,#2 {\put(#1,#2){\circle*{0.4}}} \def\Ln#1,#2,#3,#4 {\put(#1,#2){\line(#3,#4){2}}} \def\Diamond#1,#2 {\put(#1,#2){\begin{picture}(0,0)(0,0) \Dt 2,0 \Dt -2,0 \Dt 0,2 \Dt 0,-2 \Ln -2,0,1,1 \Ln -2,0,1,-1 \Ln 2,0,-1,1 \Ln 2,0,-1,-1 \end{picture}}} \def\Boxx#1,#2 {\put(#1,#2){\begin{picture}(0,0)(0,0) \Diamond 0,1 \Diamond 0,-1 \Ln 0,1,0,1 \Ln 0,-1,0,-1 \Ln -2,-1,0,1 \Ln 2,-1,0,1 \end{picture}}} \thicklines \setlength{\unitlength}{6mm} .