anchor.diff:              let tokenData = match parserSource.TokenData with | None -> "" | Some f -> f e.Tag|> string
               outErrors.Add(tokenStr + tokenData, errdict.[e])
           outErrors
  -    let processVertex v = 
  +    let processVertex v =
           makeReductions v
   
           let newGssVs = new ResizeArray<_>(2)
           for gssVertex in v.unprocessedGssVertices do 
               newGssVs.AddRange(push v gssVertex)
  -        checkEdges v
  +        if not <| ResizeArray.isEmpty(v.unprocessedGssVertices)
  +        then
  +            checkEdges v
           v.unprocessedGssVertices.Clear()
           if newGssVs.Count > 0 
           then
  
positive.code:     for v in innerGraph.Vertices do
          outEdgesInnerGraph.[v.vNum] <- innerGraph.OutEdges v |> Array.ofSeq
      let gssVertexesToPrefixes = new Dictionary<_,_>()
      let vertexesToPrefixes = new Dictionary<_,_>()
      for v in innerGraph.Vertices do
          vertexesToPrefixes.Add(v, new ResizeArray<Prefix<'TokenType>>())
      let edgesToPrefixes = new Dictionary<_,ResizeArray<Prefix<'TokenType>>>()
      for v in innerGraph.Vertices do
          for e in outEdgesInnerGraph.[v.vNum] do
              edgesToPrefixes.Add(e, new ResizeArray<Prefix<'TokenType>>())
      let errorEdges = new Dictionary<QuickGraph.TaggedEdge<_,_>,_>()
      
      let drawDot (tokenToNumber : _ -> int) (tokens : BlockResizeArray<_>) (leftSide : int[])
  
negative.code:             graphV.passingReductions.Remove((v, e)) |> ignore
  
      let checkEdges (v:VInfo<_>) =
         for e in outEdgesInnerGraph.[v.vNum] do
              for npprefix in notPassedPrefixes.[e] do
                  if not <| passedPrefixes.[e].Contains(npprefix)
                  then
                      if not <| errorEdges.ContainsKey(e)
                      then
                          errorEdges.Add(e, new ResizeArray<Prefix<'TokenType>>())
                      addPrefix errorEdges.[e] npprefix
              passedPrefixes.[e].Clear()
              notPassedPrefixes.[e].Clear()
  
      let buildErrors (errdict:Dictionary<QuickGraph.TaggedEdge<_,_>,ResizeArray<Prefix<'TokenType>>>) =
          let outErrors = new Dictionary<string,ResizeArray<Prefix<'TokenType>>>()
  