anchor.diff:  	    end;
   	#k_map{es=Es} ->
   	    Keys = [begin
  -			#k_map_pair_assoc{key=#k_literal{val=Key}} = Pair,
  +			#k_map_pair_exact{key=#k_literal{val=Key}} = Pair,
   			Key
   		    end || Pair <- Es],
   	    %% multiple keys may have the same name
  
positive.code:     pat_list_vars(Es);
  pat_vars(#k_map{es=Es}) ->
      pat_list_vars(Es);
  pat_vars(#k_map_pair_assoc{val=V}) ->
      pat_vars(V).
  
  pat_list_vars(Ps) ->
  
negative.code: 				     [N|As];
  				 #k_map{es=Es} ->
  				     Vals = [V ||
  						#k_map_pair_exact{val=V} <- Es],
  				     Vals ++ As;
  				 _Other ->
  				     As
  