anchor.diff:                      Nth = length(Cmds)-N+1,
                       case N == 1 of 
                           true ->
  -                            [lists:neth(Nth, Cmds)];
  +                            [lists:nth(Nth, Cmds)];
                           _ ->
                               {lists:nth(Nth, Cmds), 
                                {lazy_gen, fun()->
  
positive.code:                             {lists:nth(Nth, Cmds), 
                               {lazy_gen, fun()->
                                                  get_next_unfold_app_command(
                                                    {File1, {lazy_file_gen, NextFileGen}}, FA, MFAorPos, SearchPaths, N-1)
                                          end}}        
                      end
              end
  
negative.code:             get_next_unfold_app_command(
                {F, NextFileGen}, FA, MFAorPos, SearchPaths, -1)
      end.
  get_next_unfold_app_command({File, NextFileGen}, FA, 
                              MFAorPos, SearchPaths, N) ->
      FAs= get_fun_arity({File, NextFileGen}, FA, true),
      case FAs of
          []->[]; 
          [{F, A}] ->  
  