anchor.diff:                    RestTreeAcc, SyncAccSend, SyncAccRcv,
                     MySyncAccDRK, MySyncAccDRLCount, OtherSyncAccDRLCount, AccCmp, AccSkip,
                     NextLvlNodesActIN, HashCmpI_IN, HashCmpL_IN) ->
  +    % either stop_leaf or stop_empty_leaf2
       case merkle_tree:is_leaf(Node) of
           true  ->
               case merkle_tree:is_empty(Node) of
  -                false ->
  +                false -> % stop_leaf
                       MaxItemsCount = erlang:min(Params#merkle_params.bucket_size,
                                                  MyMaxItemsCount),
                       SyncAccRcv1 =
                           [{MaxItemsCount, merkle_tree:get_bucket(Node), 1} | SyncAccRcv],
                       OtherSyncAccDRLCount1 = OtherSyncAccDRLCount,
                       HashCmpL_OUT = HashCmpL_IN + 1;
  -                true ->
  +                true -> % stop_empty_leaf2
  +                    % -> resolved directly at the other node, i.e. without a trivial sub process
                       SyncAccRcv1 = SyncAccRcv,
                       OtherSyncAccDRLCount1 = OtherSyncAccDRLCount + 1,
                       HashCmpL_OUT = HashCmpL_IN
               end;
  -        false ->
  +        false -> % stop_leaf
               {MyKVItems, LeafCount} = merkle_tree:get_items([Node]),
               SyncAccRcv1 =
                   [{MyMaxItemsCount, MyKVItems, LeafCount} | SyncAccRcv],
  
positive.code:                              MySyncAccDRK, MySyncAccDRLCount, OtherSyncAccDRLCount,
                               SyncIN, AccCmp + 1, AccSkip,
                               NextLvlNodesActOUT, HashCmpI_OUT, HashCmpL_IN);
         (not IsLeafNode) andalso IsLeafHash andalso Hash =/= none ->
             % inner node here, non-empty leaf there
             % don't compare hashes -> this is an exact process based on the tags
             {MyKVItems, LeafCount} = merkle_tree:get_items([Node]),
             Sync = {MyMaxItemsCount, MyKVItems, LeafCount},
             merkle_check_node(TK, TN, SigSizeI, SigSizeL,
  
negative.code:                              SyncIN, AccCmp + 1, AccSkip + Skipped,
                               NextLvlNodesActIN, HashCmpI_OUT, HashCmpL_OUT);
         (not IsLeafNode) andalso (not IsLeafHash) ->
             % both inner nodes
             Childs = merkle_tree:get_childs(Node),
             NextLvlNodesActOUT = NextLvlNodesActIN + Params#merkle_params.branch_factor,
             HashCmpI_OUT = HashCmpI_IN + 1,
  