anchor.diff:                      let newIndex = packEdgePos outEdge 0
                       pushContext newIndex nextState !currentGSSNode newLength)
               else//reached end of input.
  -                // put dummyIndex in stack
  +                //put dummyIndex in stack
                   let dummyIndex = packEdgePos dummyEdge curEdge
                   pushContext dummyIndex nextState !currentGSSNode newLength
   
  
positive.code:                 
          let cond, nextState = parser.StateAndTokenToNewState.TryGetValue dictionaryKey
          if cond
          then
              eatTerm nextState curEdge curPos
  
          for curNonterm, nextState in outEdges do
              if curNonterm = anyNonterm
  
negative.code: 
          if startV.P.Count > 0
          then startV.P |> ResizeArray.iter(fun (newIndex, l) -> addContext newIndex stateToContinue currentVertex (len + l))        
          else addContext index posInGrammar startV 0us
              
      /// 
      let pop () =
  