anchor.diff:                              condition := false
                           | 
                               None _ -> 
  -                                containsError !currentVertexInInput !structures.CurrentLabel !currentGSSNode !structures.CurrentN
  -                                ()
  +                                containsError !currentVertexInInput !structures.CurrentLabel !currentGSSNode !structures.CurrentN !currentPath
  +                                
                       else 
                           let getIndex nTerm term = 
                               let mutable index = nTerm
  
positive.code:                         currentGSSNode
                          currentVertexInInput
                          pop
  
                      
          let control () =
               while not !stop do
  
negative.code:                     arr.DoForAll (fun tree  ->
                          let y = structures.GetNodeP findSppfNode findSppfPackedNode structures.Dummy label ast tree
                          let index = getRightExtension <| structures.GetTreeExtension y 
                          structures.AddContext setU index label vertex y !currentPath)
              v
                  
          let pop (u : Vertex) (i : int) (z : int<nodeMeasure>) =
  