anchor.diff:  format_i_number(#{}) -> [].
   
   format_terminator(#b_br{anno=A,bool=#b_literal{val=true},succ=Lbl}, _) ->
  -    io_lib:format("  ~sbr label ~p\n", [format_i_number(A),Lbl]);
  +    io_lib:format("  ~sbr ~ts\n", [format_i_number(A),format_label(Lbl)]);
   format_terminator(#b_br{anno=A,bool=#b_literal{val=false},fail=Lbl}, _) ->
  -    io_lib:format("  ~sbr label ~p\n", [format_i_number(A),Lbl]);
  +    io_lib:format("  ~sbr ~ts\n", [format_i_number(A),format_label(Lbl)]);
   format_terminator(#b_br{anno=A,bool=Bool,succ=Succ,fail=Fail}, FuncAnno) ->
  -    io_lib:format("  ~sbr ~ts, label ~p, label ~p\n",
  -                  [format_i_number(A),format_arg(Bool, FuncAnno),Succ,Fail]);
  +    io_lib:format("  ~sbr ~ts, ~ts, ~ts\n",
  +                  [format_i_number(A),
  +                   format_arg(Bool, FuncAnno),
  +                   format_label(Succ),
  +                   format_label(Fail)]);
   format_terminator(#b_switch{anno=A,arg=Arg,fail=Fail,list=List}, FuncAnno) ->
  -    io_lib:format("  ~sswitch ~ts, label ~p, ~ts\n",
  -                  [format_i_number(A),format_arg(Arg, FuncAnno),Fail,
  -                   format_list(List,FuncAnno)]);
  +    io_lib:format("  ~sswitch ~ts, ~ts, ~ts\n",
  +                  [format_i_number(A),format_arg(Arg, FuncAnno),
  +                   format_label(Fail),
  +                   format_switch_list(List, FuncAnno)]);
   format_terminator(#b_ret{anno=A,arg=Arg}, FuncAnno) ->
       io_lib:format("  ~sret ~ts\n", [format_i_number(A),format_arg(Arg, FuncAnno)]).
   
  
positive.code: format_arg(#b_var{}=Arg, FuncAnno) ->
      format_var(Arg, FuncAnno);
  format_arg(#b_literal{val=Val}, _FuncAnno) ->
      io_lib:format("literal ~p", [Val]);
  format_arg(#b_remote{mod=Mod,name=Name,arity=Arity}, FuncAnno) ->
      io_lib:format("remote (~ts):(~ts)/~p",
                    [format_arg(Mod, FuncAnno),format_arg(Name, FuncAnno),Arity]);
  format_arg(#b_local{name=Name,arity=Arity}, FuncAnno) ->
      io_lib:format("local ~ts/~p", [format_arg(Name, FuncAnno),Arity]);
  format_arg({Value,Label}, FuncAnno) when is_integer(Label) ->
      io_lib:format("{ ~ts, ~p }", [format_arg(Value, FuncAnno),Label]);
  format_arg(Other, _) ->
      io_lib:format("*** ~p ***", [Other]).
  
  format_list(List, FuncAnno) ->
      Ss = [io_lib:format("{ ~ts, ~ts }", [format_arg(Val, FuncAnno),format_label(L)]) ||
               {Val,L} <- List],
      io_lib:format("[ ~ts ]", [lists:join(", ", Ss)]).
  
  format_label(L) ->
      ["label ",integer_to_list(L)].
  
  format_anno(#{n:=_}=Anno) ->
      format_anno(maps:remove(n, Anno));
  
negative.code:      io_lib:format("%% Counter = ~p\n", [Counter]),
       [format_anno(Key, Value) ||
           {Key,Value} <- lists:sort(maps:to_list(Anno))],
       io_lib:format("function `~p`:`~p`(~ts) {\n",
                     [M, F, format_args(Args, FuncAnno)]),
       [format_live_interval(Var, FuncAnno) || Var <- Args],
       format_blocks(ReachableBlocks, Blocks, FuncAnno),
       case Unreachable of
  