anchor.diff:  insert(zones, {_N, #zone{} = Zone})->
       Write = fun() -> mnesia:write(zones, Zone, write) end,
       ok = mnesia:activity(transaction, Write),
  +    ok;
  +insert(authorities, #authorities{} = Auth) ->
  +    Write = fun() -> mnesia:write(authorities, Auth, write) end,
  +    ok = mnesia:activity(transaction, Write),
       ok.
  -
   
   -spec delete_table(atom()) -> true | {aborted, any()}.
   delete_table(Table) ->
  
positive.code:             ok
      end.
  
  -spec insert(atom(), #zone{}) -> true | any().
  insert(zones, #zone{} = Zone)->
      Write = fun() -> mnesia:write(zones, Zone, write) end,
      ok = mnesia:activity(transaction, Write),
  
negative.code:     mnesia:activity(transaction, MatchObject).
  
  -spec foldl(fun(), list(), atom())  -> Acc :: term() | {error, Reason :: term()}.
  foldl(Iterator, _Acc, Table) ->
      Exec = fun() -> mnesia:foldl(Iterator, [], Table) end,
      case mnesia:is_transaction() of
      true ->
          Exec();
      false ->
          mnesia:activity(transaction, Exec)
      end.
  
  -spec empty_table(atom()) -> ok | {aborted, term()}.
  empty_table(Table) ->
  