anchor.diff:              end
       end;
   to_expr([_|_]=List, L, _, St) ->
  -    case is_posint_list(List) of
  +    case lfe_lib:is_posint_list(List) of
           true -> {{string,L,List},St};
           false ->
               illegal_code_error(L, list)         %Not right!
  
positive.code:     {Em,St1} = to_expr(Map, L, Vt, St0),
      {Eks,St2} = to_exprs(Keys, L, Vt, St1),
      Fun = fun (K, {F,St}) ->
  		  to_remote_call({atom,L,maps}, {atom,L,remove}, [K,F], L, St)
  	  end,
      lists:foldl(Fun, {Em,St2}, Eks).
  
  %% to_map_pairs(Pairs, LineNumber, VarTable, State) -> {Fields,State}.
  
negative.code:     {Ep2,Pvs2,Vt2,St2} = to_pat(P2, L, Pvs1, Vt1, St1),
      {{match,L,Ep1,Ep2},Pvs2, Vt2,St2};
  to_pat([_|_]=List, L, Pvs, Vt, St) ->
      case lfe_lib:is_posint_list(List) of
          true -> {to_lit(List, L),Pvs,Vt,St};
          false -> illegal_code_error(L, string)
      end.
  