anchor.diff:      notify_group(ScopeMon, MG, join, Group, [Pid]);
   join_local_update_ets(Scope, ScopeMon, MG, Group, Pids) ->
       case ets:lookup(Scope, Group) of
  -        [{Group, All, Local}] ->
  +        [{_Group, All, Local}] ->
               ets:insert(Scope, {Group, Pids ++ All, Pids ++ Local});
           [] ->
               ets:insert(Scope, {Group, Pids, Pids})
  
positive.code: 
  join_remote_update_ets(Scope, ScopeMon, MG, Group, Pid) when is_pid(Pid) ->
      case ets:lookup(Scope, Group) of
          [{Group, All, Local}] ->
              ets:insert(Scope, {Group, [Pid | All], Local});
          [] ->
              ets:insert(Scope, {Group, [Pid], []})
  
negative.code:         {Pids, NewRemoteGroups} ->
              sync_groups(Scope, ScopeMon, MG, NewRemoteGroups, Tail);
          {OldPids, NewRemoteGroups} ->
              [{_Group, AllOldPids, LocalPids}] = ets:lookup(Scope, Group),
              %% should be really rare...
              AllNewPids = Pids ++ AllOldPids -- OldPids,
              true = ets:insert(Scope, {Group, AllNewPids, LocalPids}),
  