anchor.diff:          {value, {category, record_type}} -> 
   	    throw({error, "Record type cannot be replaced by a variable."});	 
           {value, {category, guard_expression}} -> 
  -	    throw({error, "Generalisation of a guard expression is not supported."});
  +	    throw({error, "Generalisation over a guard expression is not supported."});
   	{value, {category, application_op}} -> 
   	    GuardRanges=[refac_util:get_range(G) || 
   			    C <-Cs, 
  
positive.code: 	    {Start, End} = refac_util:get_range(Exp),
  	    case [{S,E}||{S, E}<- GuardRanges, S=<Start, End=<E] of
  		[] -> ok;
  		_ ->throw({error, "Generalisation of a function application "
  			   "in a guard expression is not supported."})
  	    end;
  	_ -> ok     
  
negative.code:     case Exp_Export_Vars of
  	[_|_] ->
  	    throw({error, "Wrangler does not support generalisation "
  		   "over an expression that exports variables(s)!"});
  	_ -> ok
      end,
      F= fun(Node, Acc) ->
  