anchor.diff:          _ ->
               [[E]]       % a single expression
       end.
  +
  +%% =====================================================================
  +%% @spec type(Node::syntaxTree()) -> atom()
  +%%
  +%% @doc The function is the same as erl_syntax:type/1. It returns the 
  +%% type tag of <code>Node</code>. If <code>Node</code>
  +%% does not represent a syntax tree, evaluation fails with reason
  +%% <code>badarg</code>. Node types currently defined are:
  +%% <p><center><table border="1">
  +%%  <tr>
  +%%   <td>application</td>
  +%%   <td>arity_qualifier</td>
  +%%   <td>atom</td>
  +%%   <td>attribute</td>
  +%%  </tr><tr>
  +%%   <td>binary</td>
  +%%   <td>binary_field</td>
  +%%   <td>block_expr</td>
  +%%   <td>case_expr</td>
  +%%  </tr><tr>
  +%%   <td>catch_expr</td>
  +%%   <td>char</td>
  +%%   <td>class_qualifier</td>
  +%%   <td>clause</td>
  +%%  </tr><tr>
  +%%   <td>comment</td>
  +%%   <td>cond_expr</td>
  +%%   <td>conjunction</td>
  +%%   <td>disjunction</td>
  +%%  </tr><tr>
  +%%   <td>eof_marker</td>
  +%%   <td>error_marker</td>
  +%%   <td>float</td>
  +%%   <td>form_list</td>
  +%%  </tr><tr>
  +%%   <td>fun_expr</td>
  +%%   <td>function</td>
  +%%   <td>generator</td>
  +%%   <td>if_expr</td>
  +%%  </tr><tr>
  +%%   <td>implicit_fun</td>
  +%%   <td>infix_expr</td>
  +%%   <td>integer</td>
  +%%   <td>list</td>
  +%%  </tr><tr>
  +%%   <td>list_comp</td>
  +%%   <td>macro</td>
  +%%   <td>match_expr</td>
  +%%   <td>module_qualifier</td>
  +%%  </tr><tr>
  +%%   <td>nil</td>
  +%%   <td>operator</td>
  +%%   <td>parentheses</td>
  +%%   <td>prefix_expr</td>
  +%%  </tr><tr>
  +%%   <td>qualified_name</td>
  +%%   <td>query_expr</td>
  +%%   <td>receive_expr</td>
  +%%   <td>record_access</td>
  +%%  </tr><tr>
  +%%   <td>record_expr</td>
  +%%   <td>record_field</td>
  +%%   <td>record_index_expr</td>
  +%%   <td>rule</td>
  +%%  </tr><tr>
  +%%   <td>size_qualifier</td>
  +%%   <td>string</td>
  +%%   <td>text</td>
  +%%   <td>try_expr</td>
  +%%  </tr><tr>
  +%%   <td>tuple</td>
  +%%   <td>underscore</td>
  +%%   <td>variable</td>
  +%%   <td>warning_marker</td>
  +%%  </tr>
  +%% </table></center></p>
  +type(Node) ->
  +    refac_syntax:type(Node).
  
positive.code:                           Acc
                    end
            end,
      ordsets:to_list(ast_traverse_api:fold(Fun,ordsets:new(),Node)).
   
  %%@doc Returns all the variable names that are declared within `Node', and 
  %%    also used by the code outside `Node'.
  
negative.code:                           Acc
                    end
            end,
      lists:reverse(ast_traverse_api:full_tdTU(Fun, [], AST)).
    
  
  get_expr_seqs(T) ->
  