anchor.diff:      lfe_io:format1(<<"bad ~w guard form">>, [Form]);
   format_error({bad_pattern,Pat}) ->
       lfe_io:format1(<<"bad ~w pattern">>, [Pat]);
  -format_error({unbound_symb,S}) ->
  +format_error({unbound_symbol,S}) ->
       lfe_io:format1(<<"symbol ~w is unbound">>, [S]);
   format_error({undefined_function,{F,Ar}}) ->
       lfe_io:format1("function ~w/~w undefined", [F,Ar]);
   format_error({multi_var,S}) ->
       lfe_io:format1("variable ~w multiply defined", [S]);
  -%% Functions, imports and exports
  +%% Functions, imports, exports and aliases.
   format_error({redefine_function,{F,Ar}}) ->
       lfe_io:format1("function ~w/~w already defined", [F,Ar]);
   format_error({bad_fdef,F}) ->
  
positive.code:     %% case is_element(S, Bvs) or lfe_env:is_vbound(S, Env) of
      case ordsets:is_element(S, Bvs) or le_hasv(S, Env) of
          true -> St;
          false -> add_error(L, {unbound_symb,S}, St)
      end;
  pat_bit_size(_, _, _, _, _, L, St) -> illegal_bitsize_error(L, St).
  
  
negative.code:                   [F,Ar,M1,M2]);
  format_error({define_imported_function,{F,Ar}}) ->
      lfe_io:format1(<<"defining imported function ~w/~w">>, [F,Ar]);
  format_error({redefine_module_alias,A}) ->
      lfe_io:format1(<<"redefining ~w module alias">>, [A]);
  format_error({circular_module_alias,A}) ->
      lfe_io:format1(<<"circular module alias for ~w">>, [A]);
  %% Others
  format_error({illegal_literal,Lit}) ->
      lfe_io:format1(<<"illegal literal value ~w">>, [Lit]);
  