anchor.diff:  
   %% =====================================================================
   %% @spec pos_to_expr(Tree::syntaxTree(), Start::Pos, End::Pos) ->
  -%%                  {ok, syntaxTree()} | {error, none}
  +%%                  {ok, syntaxTree()} | {error, string()}
   %%
   %%       Pos={integer(), integer()}
   %% @doc Get the largest, left-most expression enclosed by the start and end locations.
  
positive.code:       {_Rq, false} -> until(F, T, Others)
      end.
  
  %% =====================================================================
  %% @spec stop_tdTP(Function, Tree::syntaxTree(), Others::[term()])->  syntaxTree()
  %%       Function = (syntaxTree(),{term()}) -> {syntaxTree(), bool()}
  
negative.code: %% @see pos_to_fun_def/2.
  
  -spec (pos_to_fun_name(Node::syntaxTree(), Pos::pos()) ->
                          {ok, {atom(), atom(), integer(), pos(), pos()}} | {error, string()}).
  pos_to_fun_name(Node, Pos) ->
      case once_tdTU(fun pos_to_fun_name_1/2, Node, Pos) of
        {_, false} -> {error, "You have not selected a function name!"};
        {R, true} -> {ok, R}
      end. 
  
  