diff --git a/tests/vault/gear/scheduler-stress-test.cpp b/tests/vault/gear/scheduler-stress-test.cpp
index e0faf6a09..00119394f 100644
--- a/tests/vault/gear/scheduler-stress-test.cpp
+++ b/tests/vault/gear/scheduler-stress-test.cpp
@@ -161,10 +161,13 @@ SHOW_EXPR(micros);
           CHECK (micros < 550);
           CHECK (micros > 450);
           
-          auto levelWeights = testLoad.allLevelWeights();
+          std::vector<TestChainLoad<>::Agg> levelWeights = testLoad.allNodes().processingLayer<TestChainLoad<>::WeightAggregator>().effuse();
 SHOW_EXPR(levelWeights.size())
           for (auto& w : levelWeights)
-            cout<<"level:"<<w.first<<" ∑="<<w.second<<endl;
+            {
+              auto& [level,nodes,weight] = w;
+              cout<<"level:"<<level<<" nodes:"<<nodes<<" ∑="<<weight<<endl;
+            }
           
           using Node = TestChainLoad<>::Node;
           auto nodeData = testLoad.allNodes()
@@ -172,27 +175,28 @@ SHOW_EXPR(levelWeights.size())
                                   .effuse();
           for (auto& n : nodeData)
             cout<<"level:"<<n.first<<" w="<<n.second<<endl;
+          auto getWeight = [&](uint level) { return std::get<2> (levelWeights[level]); };
           CHECK (nodeData[22].first == 16);
-          CHECK (nodeData[23].first == 17);  CHECK (nodeData[23].second == 3);  CHECK (levelWeights[17].second == 3);
+          CHECK (nodeData[23].first == 17);  CHECK (nodeData[23].second == 3);  CHECK (getWeight(17) == 3);
           
           CHECK (nodeData[24].first == 18);  CHECK (nodeData[24].second == 0);
           CHECK (nodeData[25].first == 18);  CHECK (nodeData[25].second == 0);
           CHECK (nodeData[26].first == 18);  CHECK (nodeData[26].second == 0);
           CHECK (nodeData[27].first == 18);  CHECK (nodeData[27].second == 0);
-          CHECK (nodeData[28].first == 18);  CHECK (nodeData[28].second == 0);  CHECK (levelWeights[18].second == 0);
+          CHECK (nodeData[28].first == 18);  CHECK (nodeData[28].second == 0);  CHECK (getWeight(18) == 0);
           
           CHECK (nodeData[29].first == 19);  CHECK (nodeData[29].second == 2);
           CHECK (nodeData[30].first == 19);  CHECK (nodeData[30].second == 2);
           CHECK (nodeData[31].first == 19);  CHECK (nodeData[31].second == 2);
           CHECK (nodeData[32].first == 19);  CHECK (nodeData[32].second == 2);
-          CHECK (nodeData[33].first == 19);  CHECK (nodeData[33].second == 2);  CHECK (levelWeights[19].second == 10);
+          CHECK (nodeData[33].first == 19);  CHECK (nodeData[33].second == 2);  CHECK (getWeight(19) == 10);
           
           CHECK (nodeData[34].first == 20);  CHECK (nodeData[34].second == 3);
-          CHECK (nodeData[35].first == 20);  CHECK (nodeData[35].second == 2);  CHECK (levelWeights[20].second == 5);
+          CHECK (nodeData[35].first == 20);  CHECK (nodeData[35].second == 2);  CHECK (getWeight(20) == 5);
           
           CHECK (nodeData[36].first == 21);  CHECK (nodeData[36].second == 1);
           CHECK (nodeData[37].first == 21);  CHECK (nodeData[37].second == 1);
-          CHECK (nodeData[38].first == 21);  CHECK (nodeData[38].second == 3);  CHECK (levelWeights[21].second == 5);
+          CHECK (nodeData[38].first == 21);  CHECK (nodeData[38].second == 3);  CHECK (getWeight(21) == 5);
         }
       
       
diff --git a/tests/vault/gear/test-chain-load.hpp b/tests/vault/gear/test-chain-load.hpp
index be90c638a..c43abf05e 100644
--- a/tests/vault/gear/test-chain-load.hpp
+++ b/tests/vault/gear/test-chain-load.hpp
@@ -748,23 +748,74 @@ namespace test {
         }
       
       
+      using Agg = std::tuple<size_t,size_t,size_t>;
+      
+      template<class IT>
+      class WeightAggregator
+        : public IT
+        {
+          std::optional<Agg> agg_{};
+          
+          IT&
+          srcIter()  const
+            {
+              return unConst(*this);
+            }
+          
+          static void
+          account (Agg& agg, IT const& item)
+            {
+              auto& [level,nodes,weight] = agg;
+              auto& n = *item;
+              level = n.level;
+              weight += n.weight;
+              ++nodes;
+            }
+          void
+          pullGroup()
+            {
+              size_t group = srcIter()->level;
+              agg_ = Agg{};
+              do{
+                  account (*agg_, srcIter());
+                  ++ srcIter();
+                }
+              while (srcIter() and group == srcIter()->level);
+            }
+        public:
+          WeightAggregator() =default;
+          WeightAggregator (IT&& src)
+            : IT{move (src)}
+            {
+              if (srcIter())
+                pullGroup();
+            }
+          bool
+          checkPoint()  const
+            {
+              return bool(agg_);
+            }
+          
+          Agg&
+          yield()  const
+            {
+              return *unConst(this)->agg_;
+            }
+          
+          void
+          iterNext()
+            {
+              if (srcIter())
+                pullGroup();
+              else
+                agg_ = std::nullopt;
+            }
+        };
       /** calculate node weights aggregated per level */
       auto
       allLevelWeights()
         {
-          std::vector<std::pair<size_t,size_t>> weightTab;
-          weightTab.reserve (topLevel()+1);
-          auto currLevel = [&]()-> decltype(auto) { return weightTab.back();           };
-          auto nextLevel = [&](size_t levelID)    { weightTab.emplace_back(levelID,0); };
-          nextLevel (0);
-          for (Node& n : allNodes())
-            {
-              if (n.level > currLevel().first)
-                nextLevel(n.level);
-               // aggregate weights within level
-              currLevel().second += n.weight;
-            }
-          return weightTab;
+//          return allNodes().processingLayer<WeightAggregator>();
         }
       
       
diff --git a/wiki/thinkPad.ichthyo.mm b/wiki/thinkPad.ichthyo.mm
index 48b709a25..2aad2cb4d 100644
--- a/wiki/thinkPad.ichthyo.mm
+++ b/wiki/thinkPad.ichthyo.mm
@@ -107404,8 +107404,8 @@ Date:&#160;&#160;&#160;Thu Apr 20 18:53:17 2023 +0200<br/>
 <icon BUILTIN="button_ok"/>
 </node>
 <node BACKGROUND_COLOR="#eef0c5" COLOR="#990000" CREATED="1702944889122" ID="ID_816186443" MODIFIED="1703807949690" TEXT="Berechnung der systematisch-erwartbaren Ausf&#xfc;hrungszeit">
-<linktarget COLOR="#5d567f" DESTINATION="ID_816186443" ENDARROW="Default" ENDINCLINATION="-25;77;" ID="Arrow_ID_280715198" SOURCE="ID_1983964457" STARTARROW="None" STARTINCLINATION="-621;-17;"/>
 <linktarget COLOR="#618eb4" DESTINATION="ID_816186443" ENDARROW="Default" ENDINCLINATION="-871;-40;" ID="Arrow_ID_888227312" SOURCE="ID_1434946452" STARTARROW="None" STARTINCLINATION="-203;20;"/>
+<linktarget COLOR="#5d567f" DESTINATION="ID_816186443" ENDARROW="Default" ENDINCLINATION="-25;77;" ID="Arrow_ID_280715198" SOURCE="ID_1983964457" STARTARROW="None" STARTINCLINATION="-621;-17;"/>
 <icon BUILTIN="pencil"/>
 <node CREATED="1702944906320" ID="ID_1870513553" MODIFIED="1702944934194" TEXT="per Chain-Load Graph-processing">
 <icon BUILTIN="info"/>
@@ -107487,6 +107487,50 @@ Date:&#160;&#160;&#160;Thu Apr 20 18:53:17 2023 +0200<br/>
 <node CREATED="1703806119013" ID="ID_848627487" MODIFIED="1703806130911" TEXT="For-Schleife mit schleppendem Aggregat"/>
 <node CREATED="1703807871832" ID="ID_414635297" MODIFIED="1703807880606" TEXT="Gewichte pro Level aufsummieren"/>
 </node>
+<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1703882997602" ID="ID_1587426873" MODIFIED="1703883014897" TEXT="nachfolgend w&#xe4;re aber eine Pipeline doch nicht schlecht">
+<icon BUILTIN="idea"/>
+<node BACKGROUND_COLOR="#f0d5c5" COLOR="#990033" CREATED="1703883016888" ID="ID_1740211471" MODIFIED="1703895721626" TEXT="also einen zweiten Anlauf versuchen">
+<icon BUILTIN="yes"/>
+<node CREATED="1703895722656" ID="ID_527352372" MODIFIED="1703895731221" TEXT="sschwere Geburt">
+<icon BUILTIN="smiley-angry"/>
+<node CREATED="1703895737462" ID="ID_998389333" MODIFIED="1703895770446" TEXT="ich bin an der Idee &#xbb;schleppende Iteration&#xab; h&#xe4;ngen geblieben"/>
+<node CREATED="1703895773857" ID="ID_91740622" MODIFIED="1703895796842" TEXT="dem entsprechend wolle ich das &#xbb;pull&#xab; immerfort lazy / on demand machen"/>
+</node>
+<node CREATED="1703895798194" ID="ID_21629149" MODIFIED="1703895969078" TEXT="entscheidende Einsichten">
+<icon BUILTIN="idea"/>
+<node CREATED="1703895835761" ID="ID_1930618506" MODIFIED="1703895838540" TEXT="man mu&#xdf; eine Gruppe voraus pullen"/>
+<node CREATED="1703895939371" ID="ID_1543713695" MODIFIED="1703895964277" TEXT="Invariante: steht hinter einem Gruppenwechsel"/>
+<node CREATED="1703895844842" ID="ID_1108667761" MODIFIED="1703895937211" TEXT="man braucht zwingend eine zus&#xe4;tzliche State-Variable wegen Iterationsende">
+<richcontent TYPE="NOTE"><html>
+  <head>
+    
+  </head>
+  <body>
+    <p>
+      weil die Invariante eben auch <i>erf&#252;llt</i>&#160;ist, wenn man hinter dem Ende steht; insofern ist die Auswertung ja tats&#228;chlich &#187;schleppend&#171;, d.h. man gibt immer die <i>vorhergehende</i>&#160;Gruppe aus
+    </p>
+  </body>
+</html>
+</richcontent>
+</node>
+</node>
+<node COLOR="#338800" CREATED="1703896048196" ID="ID_92615600" MODIFIED="1703898484617" TEXT="bestehende Funktionalit&#xe4;t damit reproduziert">
+<icon BUILTIN="button_ok"/>
+</node>
+</node>
+<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1703895976686" ID="ID_233747473" MODIFIED="1703895999350" TEXT="dann diese L&#xf6;sung extrahieren und verallgemeinern">
+<icon BUILTIN="flag-yellow"/>
+<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1703896008082" ID="ID_77845528" MODIFIED="1703896027228" TEXT="erst mal in TestChainLoad mit Lambdas konfigurieren">
+<icon BUILTIN="flag-yellow"/>
+</node>
+<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1703896028383" ID="ID_373477842" MODIFIED="1703896035228" TEXT="dann in den IterExplorer &#xfc;bernehmen">
+<icon BUILTIN="flag-yellow"/>
+</node>
+<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1703896035966" ID="ID_707528864" MODIFIED="1703896039984" TEXT="Test daf&#xfc;r schreiben">
+<icon BUILTIN="flag-yellow"/>
+</node>
+</node>
+</node>
 </node>
 </node>
 <node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1702944922179" ID="ID_424913055" MODIFIED="1702944931701" TEXT="Fall2: concurrent-X">