anchor.diff:  %% @see is_form/1
   %% @see rule/2
   
  --record(function, {name, clauses}).
  +-record(function, {name, clauses}). %% to be back compatible; will be 
  +                                    %% removed when wrangler no longer 
  +                                    %% uses the erl_syntax module.
  +
  +-record(func, {name, clauses}).
   
   %% type(Node) = function
   %% data(Node) = #function{name :: Name, clauses :: Clauses}
  
positive.code: function_clauses(Node) ->
      case unwrap(Node) of
        {function, _, _, _, Clauses} -> Clauses;
        Node1 -> (data(Node1))#function.clauses
      end.
  %%=============================================
  %% Added by HL;
  
negative.code: 	_  -> Node      
      end.
  
  
  syntax_tools_vsn() -> 
      Dir=code:lib_dir(syntax_tools),
      Prefix=lists:takewhile(fun(C)-> C/=$- end, lists:reverse(Dir)),
      lists:reverse(Prefix).
      
                                
  
  %%TODO:
  %% Add support for bc (binary comprehension?).
  %% eg. `<< <<X:1>> || X <- List >>'.
  