strict digraph G {
    graph [ ratio="0.7 compressed", 
    		rankdir="LR",
    		ranksep=0.75, 
     		concentrate="false", 
    		remincross="true",
    		fontname=helvetica
    		fontsize=12 
    		];
    node  [ shape=box, 
		   	style=filled,
		   	fillcolor=white,
    		fontname=helvetica
     		fontsize=12,
    		fontcolor=black 
    		];
    edge  [ 
    		];
    		