anchor.diff:                  then
                       let varName = tok |> tokToSourceString
   
  -                    if not <| List.exists (fun t -> t = varName) !defVars //it's error
  +                    //Is it error?
  +                    if not <| List.exists (fun t -> t = varName) !defVars
                       then
                           let tokData = parserSource.tokenData tok
  -                        //if it's new error
  +                        //is it new error?
                           if not <| List.exists (fun t -> parserSource.tokenData t = tokData) !errorList     
                           then errorList := tok :: !errorList 
   
  
positive.code:                         if node.children.Length <= 1 then ""
                          else ",style=\"filled\",fillcolor=red"
                      out.WriteLine (sprintf "%d [label=\"%s\"%s]" !count label color)
                      interNodeToNumber.Add (node, !count)
                      !count, true
              
              let nodeNumber, isNew = getNodeNumber interNode
  
negative.code:                     let blockString = blockToString block
  
                      out.WriteLine (sprintf "%d [label=\"%s\",shape=box]"  !count blockString)
                      blockToNumber.[block] <- !count
                      !count, true
  
              let nodeNumber, isNew = getBlockNumber block
  