clauses
% Illegal X coordinate.
place("Background",1,-10.0,0.0).
place("Background",2,1.0,0.0).
place("Background",3,1.0,1.0).
place("Background",4,0.0,1.0).
place("Background",5,0.5,0.5).
place("Foreground",1,0.05,0.05).
place("Foreground",2,0.9,0.1).
place("Foreground",3,0.9,0.9).
place("Foreground",4,0.1,0.9).
place("Foreground",5,0.5,0.5).
edge("Background","Edges",1,1,2).
edge("Background","Edges",2,2,3).
edge("Background","Edges",3,3,4).
edge("Background","Edges",6,4,5).
edge("Background","Edges",7,5,1).
edge("Background","Cut Edges",4,1,3).
edge("Background","Cut Edges",5,4,2).
edge("Foreground","Edges",1,1,2).
edge("Foreground","Edges",2,2,3).
edge("Foreground","Edges",5,3,4).
edge("Foreground","Edges",6,4,5).
edge("Foreground","Edges",7,5,1).
edge("Foreground","Cut Edges",3,2,4).
edge("Foreground","Cut Edges",4,5,3).