anchor.diff:          let create (cE : int) (cP : int) (label : int<labelMeasure>) (vertex : Vertex) curSymbol (len : uint16) =   
               let nonTermName = curSymbol
               let i = packEdgePos cE cP
  -            let ttttt = getPosOnEdge <| getLeftExtension !currentExtension
  +            ///let ttttt = getPosOnEdge <| getLeftExtension !currentExtension
               let extension = packExtension (getLeftExtension !currentExtension) i 
               let v = new Vertex(i, nonTermName)
               if edges.[nonTermName].[i] <> null
  
positive.code:                     if current.ContainsKey vertexKey
                      then
                          let trees = current.[vertexKey]
                          if not <| trees.Contains extension
                          then 
                              trees.Add extension
                              false
                          else
                              true
                      else 
                          let arr = new ResizeArray<int64<extension>>()
                          arr.Add extension
                          current.Add(vertexKey, arr)                    
                          false
                  else 
                      let dict = new SysDict<_, ResizeArray<_>>()
                      setU.[inputIndex].Add(int label, dict)
                      let arr = new ResizeArray<_>()
                      arr.Add extension
                      dict.Add(vertexKey, arr) 
                      false
              else 
                  let dict1 = new SysDict<_, _>()
                  setU.[inputIndex] <- dict1
                  let dict2 = new SysDict<_, ResizeArray<_>>()
                  dict1.Add(int label, dict2)
                  let arr = new ResizeArray<_>()
                  arr.Add extension
                  dict2.Add(vertexKey, arr)
                  false
              
          let addContext (inputVertex : int) (label : int<labelMeasure>) vertex extension len =
  
negative.code:                         then    
                              let curToken = input.Edges.[cE].Tokens.[cP] 
                              if curToken = curSymbol
                              then eatTerm ()
                          else   
                              let curEdge = 
                                  let oEdges = outEdges.[input.Edges.[cE].End]
  