anchor.diff:  
   
   %% =====================================================================
  -%% @spec is_expr(Node:: syntaxTree())-> bool()
  +%% @spec is_expr(Node:: syntaxTree())-> boolean()
   %% @doc Return true if an AST node represents an expression.
  --spec(is_expr(Node:: syntaxTree())-> bool()).
  +-spec(is_expr(Node:: syntaxTree())-> boolean()).
   is_expr(Node) ->
       As = refac_syntax:get_ann(Node),
       case lists:keysearch(category, 1, As) of
  
positive.code: 
  
  %% =====================================================================
  %% @spec bifs_side_effect_table()->[{{atom(), atom(), integer()}, bool()}]
  %% @doc The side effect table of BIFs.
  -spec(bifs_side_effect_table()->[{{atom(), atom(), integer()}, bool()}]).
  bifs_side_effect_table() ->
      [{{erlang, abs, 1}, false}, {{erlang, append_element, 2}, false}, {{erlang, atom_to_list, 1}, false},
       {{erlang, binary_to_list, 1}, false}, {{erlang, binary_to_list, 3}, false}, {{erlang, binary_to_term, 1}, false},
  
negative.code:     end.
  
  %% =====================================================================
  %% @spec once_tdTU(Function, Tree::syntaxTree(), Others::term())-> {term(), boolean()}
  %%       Function = (syntaxTree(), term()) -> {term(), boolean()}
  %%
  %% @doc Once-topdown type-unifying traversal of the abstract syntax tree with some
  %% information collected. This function does a pre-order traversal of the
  