anchor.diff:  
       
               //Initialize Graphviz algorithm
  -            let graphViz = new GraphvizAlgorithm<string, Edge<string>>(graph);
  +            let graphViz = new GraphvizAlgorithm<string, Edge<string>>(clust_graph);
               let evHandler (evArgs:FormatVertexEventArgs<string>) =
                   evArgs.VertexFormatter.Comment <- evArgs.VertexFormatter.Label
               let evHandler2 (evArgs:FormatEdgeEventArgs<string,Edge<string>>) =
  
positive.code:     let  mutable productions:Production list = []
      let  mutable starts = ""
      let mutable vertex:string list = []
      let mutable edge:(string*string*string) list = []    
      let mutable outPath = ""
  
  type FileDotEngine()  =
  
negative.code:                                    getVert'(acc@[hd],tl)
                          |_->gr.vertex<-(patt+":"+(listToString acc)+".")::gr.vertex
                  getVert'([], res)
                  gr.cluster_vertex<-gr.vertex::gr.cluster_vertex
                  gr.vertex<-[]
  
                  gr.edge<-("."+patt,patt+":"+"."+listToString(res),"entry")::gr.edge;
                  gr.edge<-(patt+":"+listToString(res)+".",patt+".","exit")::gr.edge;
  