\psset{unit=0.45cm}
%
\def\leftobject{%
\psline[linewidth=0.1,linecolor=gray](2.5,0)(2.5,4)
\psline[linewidth=0.1,linecolor=gray](0,1.33)(2.5,1.33)
\psline[linewidth=0.1,linecolor=gray](0,2.66)(2.5,2.66)
\pspolygon[linewidth=0.4,linecolor=lightgray,linearc=0.75](0,0)(0,4)(4,4)(4,0)%
}
%
\def\rightobject{%
\psline[linewidth=0.1,linecolor=gray](1.5,0)(1.5,4)
\psline[linewidth=0.1,linecolor=gray](1.5,1.33)(4,1.33)
\psline[linewidth=0.1,linecolor=gray](1.5,2.66)(4,2.66)
\pspolygon[linewidth=0.4,linecolor=lightgray,linearc=0.75](0,0)(0,4)(4,4)(4,0)%
}
%
\pspicture(1,-7)(15,8)
% \showgrid
% Right bipartite structure:
% The bipartition:
\psline[linewidth=0.15,linecolor=gray,linestyle=dashed,dash=3pt 2pt](8,-7)(8,7)
% The vertices:
\rput(2,2){\leftobject}
\rput(2,-6){\leftobject}
\rput(10,2){\rightobject}
\rput(10,-6){\rightobject}
% The involution
\psset{linewidth=0.2,linecolor=black}
\psline{c-c}(5,5)(11,5)
\psline{c-c}(5,-5)(11,-5)
\psline{c-c}(5,3)(11,-3)
\psline{c-c}(5,-3)(11,3)
% The labels
\rput(1.5,6.5){$R_1$}
\rput(1.5,-1.5){$R_2$}
\rput(5.25,4){$M$}
\rput(5.25,-4){$M$}
%
\rput(14.5,6.5){$R_1^\prime$}
\rput(14.5,-1.5){$R_2^\prime$}
\rput(10.75,4){$M$}
\rput(10.75,-4){$M$}
\endpspicture