\psset{unit=0.45cm}
%
\pspicture(5,-10)(33,12)
% \showgrid
\rput(14,0){
% The (part of the) circle
\psline[linewidth=0.4,linecolor=gray,linearc=0.75](6,7)(17,7)(17,-6)(6,-6)
% The bicoloured paths
\psset{linewidth=0.5,linecolor=lightgray,linearc=0.5,fillstyle=none}
\psline(13,-6)(14,-4)(15,-6)
\psline(9,7)(10,3)(12,5)(14,3)(15,7)
\psline(11,7)(12,5)(13,7)
\psline(7,7)(7,3)(8,0)(10,3)(11,-3)(11,-6)
% The arcs
\psset{linewidth=0.15,linecolor=black,linearc=0.4}
\psline(9,8)(9,10)(15,10)(15,8)
\psline(13,-7)(13,-8)(15,-8)(15,-7)
\psline(7,8)(7,11)(18,11)(18,-9)(11,-9)(11,-7)
\psline(11,8)(11,9)(13,9)(13,8)
\psset{linearc=0.0}
% Dangling coloured paths ...
% Red arcs:
%\psset{linewidth=0.15,linecolor=red,linestyle=dashed,dash=3pt 2pt}
\redlinestyle
\psline(13,-6)(14,-4)(13.5,-1)(13.5,0)(14,3)(15,7)
\psline(7,7)(7,3)(8,0)(9,-1)
\psline(11,7)(12,5)(10,3)(11,-3)(11,-6)
% \psline(15,7)(14,3)(13.4,0.4)
% \psline(11,-6)(11,-3)(10.6,-0.4)
% Green arcs:
% \psset{linewidth=0.15,linecolor=green,linestyle=solid}
\greenlinestyle
\psline(15,-6)(14,-4)(14.5,-1)(14.5,0)(14,3)(12,5)(13,7)
%\psline(3,7)(4,5)(4.5,4.5)
\psline(9,7)(10,3)(8,0)(7,-1)
% \psline(13,7)(12,5)(14,3)(14.6,0.4)
% Coloured points
% \psset{linewidth=0.15,linecolor=black,fillstyle=solid,fillcolor=lightgray}
\whitecirclestyle
\pscircle[fillcolor=lightgray](15,-6){0.4}
\pscircle[fillcolor=lightgray](13,-6){0.4}
\pscircle[fillcolor=lightgray](11,-6){0.4}
\pscircle[fillcolor=lightgray](7,7){0.4}
\pscircle[fillcolor=lightgray](9,7){0.4}
\pscircle[fillcolor=lightgray](11,7){0.4}
\pscircle[fillcolor=lightgray](13,7){0.4}
\pscircle[fillcolor=lightgray](15,7){0.4}
% Upper points, radial orientation
\rput(15,-8){\TRIup{mfgreen}}
\rput(13,-8){\TRIdown{red}}
\rput(11,-8){\TRIdown{red}}
\rput(7,7){\TRIdown{red}}
\rput(9,7){\TRIup{mfgreen}}
\rput(11,7){\TRIdown{red}}
\rput(13,7){\TRIup{mfgreen}}
\rput(15,7){\TRIdown{red}}
% Points of intersection
\psset{linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=lightgray}
\pscircle(10,3){0.35}
\pscircle(12,5){0.35}
\pscircle(14,3){0.35}
\pscircle(14,-4){0.35}
\pscircle[fillcolor=black](8,0){0.35}
}
\rput(0,0){
% The (part of the) circle
\psline[linewidth=0.4,linecolor=gray,linearc=0.75,fillstyle=none](6,7)(17,7)(17,-6)(6,-6)
% The bicoloured paths
\psset{linewidth=0.5,linecolor=lightgray,linearc=0.5,fillstyle=none}
\psline(13,-6)(14,-4)(15,-6)
\psline(9,7)(10,3)(12,5)(14,3)(15,7)
\psline(11,7)(12,5)(13,7)
% The arcs
\psset{linewidth=0.15,linecolor=black,linearc=0.4,fillstyle=none}
\psline(9,8)(9,10)(15,10)(15,8)
\psline(13,-7)(13,-8)(15,-8)(15,-7)
\psline[linecolor=lightgray](7,8)(7,11)(18,11)(18,-9)(11,-9)(11,-7)
\psline(11,8)(11,9)(13,9)(13,8)
\psset{linearc=0.0}
% Dangling coloured paths ...
% Red arcs:
% \psset{linewidth=0.15,linecolor=red,linestyle=dashed,dash=3pt 2pt}
\redlinestyle
\psline(13,-6)(14,-4)(13,-3)
\psline(7,7)(7,3) % (7.6,0.4)
\psline(11,7)(12,5)(10,3)(11,2)
\psline(15,7)(14,3)(13,2)
\psline(11,-6)(11,-3)%(10.6,-0.4)
% Green arcs:
% \psset{linewidth=0.15,linecolor=green,linestyle=solid}
\greenlinestyle
\psline(15,-6)(14,-4)(15,-3)
%\psline(3,7)(4,5)(4.5,4.5)
\psline(9,7)(10,3)(9,2)
\psline(13,7)(12,5)(14,3)(15,2)
% Coloured points
%\psset{linewidth=0.15,linecolor=black,fillstyle=solid,fillcolor=white}
\whitecirclestyle
\pscircle[fillcolor=lightgray](15,-6){0.4}
\pscircle[fillcolor=lightgray](13,-6){0.4}
\pscircle(11,-6){0.4}
\pscircle(7,7){0.4}
\pscircle[fillcolor=lightgray](9,7){0.4}
\pscircle[fillcolor=lightgray](11,7){0.4}
\pscircle[fillcolor=lightgray](13,7){0.4}
\pscircle[fillcolor=lightgray](15,7){0.4}
% Upper points, radial orientation
\rput(15,-8){\TRIup{mfgreen}}
\rput(13,-8){\TRIdown{red}}
\rput(11,-8){\TRIdown{red}}
\rput(7,7){\TRIdown{red}}
\rput(9,7){\TRIup{mfgreen}}
\rput(11,7){\TRIdown{red}}
\rput(13,7){\TRIup{mfgreen}}
\rput(15,7){\TRIdown{red}}
% Points of intersection
\psset{linewidth=0.1,linecolor=black,fillstyle=solid,fillcolor=black}
\pscircle(10,3){0.35}
\pscircle[fillcolor=lightgray](12,5){0.35}
\pscircle(14,3){0.35}
\pscircle(14,-4){0.35}
}
\endpspicture