anchor.diff:  	application ->
   	    Op = refac_syntax:application_operator(Node),
   	    Args = refac_syntax:application_arguments(Node),
  -	    Op1 = add_category(Op, C),
  -	    Op2 = update_ann(Op1, {category, application_op}),
  +            Op2 = update_ann(Op, {category, application_op}),
   	    Args1 = add_category(Args, C),
   	    Node1 = rewrite(Node, refac_syntax:application(Op2, Args1)),
   	    {update_ann(Node1, {category, C}), true};
  +        arity_qualifier ->
  +            Name = refac_syntax:arity_qualifier_body(Node),
  +            Arity = refac_syntax:arity_qualifier_argument(Node),
  +            Name1 = update_ann(Name, {category, name}),
  +            Arity1 = update_ann(Arity, {category, arity}),
  +            Node1 = rewrite(Node, refac_syntax:arity_qualifier(Name1, Arity1)),
  +            {update_ann(Node1, {category, C}), true};
   	match_expr ->
   	    P = refac_syntax:match_expr_pattern(Node),
   	    B = refac_syntax:match_expr_body(Node),
  
positive.code: 
  
  %% =====================================================================
  % @doc Attach syntax category information to AST nodes.
  %% =====================================================================
  %% -type (category():: pattern|expression|guard_expression|record_type|generator
  %%                    record_field| {macro_name, none|int(), pattern|expression}
  %%                    |operator
  %%-spec(add_category(Node::syntaxTree()) -> syntaxTree()).
  add_category(Node) ->
      add_category(Node, none).
  
negative.code: 	    Name1 = add_category(Name, {macro_name, NumOfArgs, C}),
  	    Args1 = case Args of
  			none -> none;
  			_ -> add_category(Args, C)  
  		    end,
              %% this is not the best solution!!!
              Args2 = [update_ann(A, {category, macro_arg})||A<-Args1],
  	    Node1 = rewrite(Node, refac_syntax:macro(Name1, Args2)),
  	    {update_ann(Node1, {category, C}), true};
  	record_access ->
  	   Argument = refac_syntax:record_access_argument(Node),
  