diff --git a/src/steam/fixture/segment.hpp b/src/steam/fixture/segment.hpp
index ac58c00d5..09d9fb70b 100644
--- a/src/steam/fixture/segment.hpp
+++ b/src/steam/fixture/segment.hpp
@@ -75,9 +75,15 @@ namespace fixture {
       // TODO: ownership??
       ///////////////////////////////////////////////////////////////////////////////////////////////////////TICKET #725 : placeholder code
     public:
-      Segment (TimeSpan covered =TimeSpan::ALL)
+      Segment (TimeSpan covered =TimeSpan::ALL
+              ,const engine::JobTicket* ticket =nullptr)
         : span_{covered}
-        , jobTicket_{&engine::JobTicket::NOP}
+        , jobTicket_{ticket? ticket : &engine::JobTicket::NOP}
+      { }
+      
+      Segment (Segment const& original, TimeSpan changed)
+        : span_{changed}
+        , jobTicket_{original.jobTicket_}
       { }
       
       // default copy acceptable
diff --git a/src/steam/fixture/segmentation.cpp b/src/steam/fixture/segmentation.cpp
index 6a853d558..472073daf 100644
--- a/src/steam/fixture/segmentation.cpp
+++ b/src/steam/fixture/segmentation.cpp
@@ -33,6 +33,9 @@
 #include "lib/time/timevalue.hpp"
 #include "lib/split-splice.hpp"
 
+using lib::time::Time;
+using lib::time::TimeSpan;
+
 
 namespace steam {
 namespace fixture {
@@ -73,14 +76,15 @@ namespace fixture {
   Segment const&
   Segmentation::splitSplice (OptTime start, OptTime after, const engine::JobTicket* jobTicket)
   {
+    ASSERT (!start or !after or start != after);
     using Iter = typename list<Segment>::iterator;
     
-    auto getStart = [](Iter elm)                                   -> Time { return elm->start(); };
-    auto getAfter = [](Iter elm)                                   -> Time { return elm->after(); };
-    auto createSeg= [](Iter pos, Time start, Time after)           -> Iter { UNIMPLEMENTED ("create new Segment"); };
-    auto emptySeg = [](Iter pos, Time start, Time after)           -> Iter { UNIMPLEMENTED ("create empty Segment");};
-    auto cloneSeg = [](Iter pos, Time start, Time after, Iter src) -> Iter { UNIMPLEMENTED ("clone Segment and modify time"); };
-    auto discard  = [](Iter pos, Iter after)                       -> Iter { UNIMPLEMENTED ("discard Segments"); };
+    auto getStart =  [](Iter elm)                                   -> Time { return elm->start(); };
+    auto getAfter =  [](Iter elm)                                   -> Time { return elm->after(); };
+    auto createSeg= [&](Iter pos, Time start, Time after)           -> Iter { return segments_.emplace (pos, TimeSpan{start, after}, jobTicket); };
+    auto emptySeg = [&](Iter pos, Time start, Time after)           -> Iter { return segments_.emplace (pos, TimeSpan{start, after}); };
+    auto cloneSeg = [&](Iter pos, Time start, Time after, Iter src) -> Iter { return segments_.emplace (pos, *src, TimeSpan{start, after}); };
+    auto discard  = [&](Iter pos, Iter after)                       -> Iter { return segments_.erase (pos,after); };
     
     
     lib::splitsplice::Algo splicer{ getStart
diff --git a/tests/core/steam/engine/mock-dispatcher.hpp b/tests/core/steam/engine/mock-dispatcher.hpp
index 411866d4a..bdb68cf5d 100644
--- a/tests/core/steam/engine/mock-dispatcher.hpp
+++ b/tests/core/steam/engine/mock-dispatcher.hpp
@@ -208,8 +208,8 @@ namespace test   {
           for (auto& spec : specs)
             {
               JobTicket* newTicket = nullptr;
-              auto seed = spec.retrieveAttribute<HashVal> ("mark");
-              tickets_.emplace_back (seed? *seed : HashVal(rand() % 1000));
+              auto seed = spec.retrieveAttribute<int> ("mark");
+              tickets_.emplace_back (seed? HashVal(*seed) : HashVal(rand() % 1000));
               newTicket = & tickets_.back();
               
               auto start = spec.retrieveAttribute<Time> ("start");
diff --git a/tests/core/steam/engine/mock-support-test.cpp b/tests/core/steam/engine/mock-support-test.cpp
index d676706af..128984ba3 100644
--- a/tests/core/steam/engine/mock-support-test.cpp
+++ b/tests/core/steam/engine/mock-support-test.cpp
@@ -149,9 +149,11 @@ namespace test  {
             CHECK (util::isSameObject (ticket, JobTicket::NOP));
           }
           {
-            MockSegmentation mockSeg{MakeRec().genNode()};
-            CHECK (1 == mockSeg.size());
-            JobTicket const& ticket = mockSeg[someTime].jobTicket();
+            MockSegmentation mockSegs{MakeRec().genNode()};
+            CHECK (1 == mockSegs.size());
+            CHECK (Time::MIN == mockSegs[someTime].start());
+            CHECK (Time::MAX == mockSegs[someTime].after());
+            JobTicket const& ticket = mockSegs[someTime].jobTicket();
             CHECK (not util::isSameObject (ticket, JobTicket::NOP));
             
             Job someJob = ticket.createJobFor(coord);
@@ -163,9 +165,41 @@ namespace test  {
             CHECK (RealClock::wasRecently (DummyJob::invocationTime (someJob)));
             CHECK (someTime == DummyJob::invocationNominalTime (someJob));
           }
+          {
+             // Marker to verify the job calls back into the right segment
+            int marker = rand() % 1000;
+            //  Build a Segmentation partitioned at 10s
+            MockSegmentation mockSegs{MakeRec()
+                                     .attrib ("start", Time{0,10}
+                                             ,"mark",  marker)
+                                     .genNode()};
+            CHECK (2 == mockSegs.size());
+            // since only start-time was given, the SplitSplice-Algo will attach
+            // the new Segment starting at 10s and expand towards +∞,
+            // while the left part of the axis is marked as NOP / empty
+            fixture::Segment const& seg1 = mockSegs[Time::ZERO];              // access anywhere < 10s
+            fixture::Segment const& seg2 = mockSegs[Time{0,20}];              // access anywhere >= 10s
+            CHECK (    util::isSameObject (seg1.jobTicket(), JobTicket::NOP));
+            CHECK (not util::isSameObject (seg2.jobTicket(), JobTicket::NOP));// this one is the active segment
+            
+            Job job = seg2.jobTicket().createJobFor(coord);
+            CHECK (not MockJobTicket::isAssociated (job, seg1.jobTicket()));
+            CHECK (    MockJobTicket::isAssociated (job, seg2.jobTicket()));
+            CHECK (marker == job.parameter.invoKey.part.a);
+            
+            job.triggerJob();
+            CHECK (DummyJob::was_invoked (job));
+            CHECK (RealClock::wasRecently (DummyJob::invocationTime (job)));
+            CHECK (marker == DummyJob::invocationAdditionalKey (job));        // DummyClosure is rigged such as to feed back the seed in `part.a`
+                                                                              // and thus we can prove this job really belongs to the marked segment
+            // create another job from the (empty) seg1
+            job = seg1.jobTicket().createJobFor (coord);
+            InvocationInstanceID empty; /////////////////////////////////////////////////////////////////////TICKET #1287 : temporary workaround until we get rid of the C base structs
+            CHECK (lumiera_invokey_eq (&job.parameter.invoKey, &empty));      // indiate that it's just a placeholder to mark a "NOP"-Job
+          }
           
           
-          TODO ("cover details of MockSegmentation");
+          TODO ("cover more details of MockSegmentation");
         }
     };
   
diff --git a/tests/core/vault/engine/dummy-job.cpp b/tests/core/vault/engine/dummy-job.cpp
index 22fa6f2d3..5b5cd2764 100644
--- a/tests/core/vault/engine/dummy-job.cpp
+++ b/tests/core/vault/engine/dummy-job.cpp
@@ -106,9 +106,9 @@ namespace engine {
         InvocationInstanceID
         buildInstanceID (HashVal seed)  const override
           {
-            InvocationInstanceID res;
-            res.part.a = seed;
-            return res;
+            InvocationInstanceID instance;
+            instance.part.a = seed;
+            return instance;
           }
         
         size_t
diff --git a/wiki/thinkPad.ichthyo.mm b/wiki/thinkPad.ichthyo.mm
index 2969c4bce..bcb738147 100644
--- a/wiki/thinkPad.ichthyo.mm
+++ b/wiki/thinkPad.ichthyo.mm
@@ -70145,8 +70145,8 @@
 </node>
 </node>
 </node>
-<node BACKGROUND_COLOR="#eef0c5" COLOR="#990000" CREATED="1682993086565" ID="ID_469257294" MODIFIED="1683076810216" TEXT="Implementierung">
-<icon BUILTIN="pencil"/>
+<node COLOR="#338800" CREATED="1682993086565" FOLDED="true" ID="ID_469257294" MODIFIED="1683250875747" TEXT="Implementierung">
+<icon BUILTIN="button_ok"/>
 <node COLOR="#435e98" CREATED="1683042576253" ID="ID_1878728765" MODIFIED="1683076796339" TEXT="Konzept">
 <icon BUILTIN="yes"/>
 <node COLOR="#435e98" CREATED="1683042638127" ID="ID_1570983964" MODIFIED="1683076788355" TEXT="Deskriptor SpliceAct">
@@ -70236,8 +70236,8 @@
 <icon BUILTIN="idea"/>
 </node>
 </node>
-<node BACKGROUND_COLOR="#eef0c5" COLOR="#990000" CREATED="1683046722945" ID="ID_113209914" MODIFIED="1683081268947" TEXT="Generalisierung">
-<icon BUILTIN="pencil"/>
+<node COLOR="#338800" CREATED="1683046722945" ID="ID_113209914" MODIFIED="1683245591577" TEXT="Generalisierung">
+<icon BUILTIN="button_ok"/>
 <node COLOR="#338800" CREATED="1683046728800" ID="ID_1510597200" MODIFIED="1683081137760" STYLE="fork" TEXT="pr&#xfc;fen ob machbar">
 <icon BUILTIN="help"/>
 </node>
@@ -70249,17 +70249,23 @@
 <node COLOR="#338800" CREATED="1683046786608" ID="ID_106487591" MODIFIED="1683081327011" TEXT="getEnd(elm)">
 <icon BUILTIN="button_ok"/>
 </node>
-<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1683081197660" ID="ID_357336924" MODIFIED="1683081311584" TEXT="createSeg(pos, start,after)">
-<icon BUILTIN="bell"/>
+<node COLOR="#338800" CREATED="1683081197660" ID="ID_357336924" MODIFIED="1683245525718" TEXT="createSeg(pos, start,after)">
+<icon BUILTIN="button_ok"/>
+<node COLOR="#435e98" CREATED="1683245530718" HGAP="29" ID="ID_1771563243" MODIFIED="1683245560983" TEXT="hierf&#xfc;r einfach das JobTicket per &#x3bb;-closure durchbeben" VSHIFT="3">
+<font NAME="SansSerif" SIZE="11"/>
 </node>
-<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1683081213154" ID="ID_180921781" MODIFIED="1683081311584" TEXT="emptySeg(pos, start,after)">
-<icon BUILTIN="bell"/>
 </node>
-<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1683081224201" ID="ID_886281397" MODIFIED="1683081311584" TEXT="cloneSeg(pos, start,after, src)">
-<icon BUILTIN="bell"/>
+<node COLOR="#338800" CREATED="1683081213154" ID="ID_180921781" MODIFIED="1683245525719" TEXT="emptySeg(pos, start,after)">
+<icon BUILTIN="button_ok"/>
 </node>
-<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1683081234023" ID="ID_263936802" MODIFIED="1683081311584" TEXT="discard(start,after)">
-<icon BUILTIN="bell"/>
+<node COLOR="#338800" CREATED="1683081224201" ID="ID_886281397" MODIFIED="1683245525718" TEXT="cloneSeg(pos, start,after, src)">
+<icon BUILTIN="button_ok"/>
+<node COLOR="#435e98" CREATED="1683245530718" HGAP="29" ID="ID_883714171" MODIFIED="1683245584960" TEXT="hierf&#xfc;r neue Segment-ctor Variante" VSHIFT="3">
+<font NAME="SansSerif" SIZE="11"/>
+</node>
+</node>
+<node COLOR="#338800" CREATED="1683081234023" ID="ID_263936802" MODIFIED="1683245525718" TEXT="discard(start,after)">
+<icon BUILTIN="button_ok"/>
 </node>
 </node>
 <node COLOR="#338800" CREATED="1683046873340" ID="ID_347563039" MODIFIED="1683081262904" TEXT="Template Parameter deduction einrichten">
@@ -70315,7 +70321,7 @@
 <icon BUILTIN="info"/>
 </node>
 <node CREATED="1682993108314" ID="ID_317827435" MODIFIED="1682993122827" TEXT="hinzu kommt die Variante, da&#xdf; leere Intervalle zusammengef&#xfc;hrt werden"/>
-<node COLOR="#338800" CREATED="1683046966788" ID="ID_1714211009" MODIFIED="1683208598606" TEXT="splitSplice-Algo isoliert testen">
+<node COLOR="#338800" CREATED="1683046966788" FOLDED="true" ID="ID_1714211009" MODIFIED="1683208598606" TEXT="splitSplice-Algo isoliert testen">
 <linktarget COLOR="#2ec3d8" DESTINATION="ID_1714211009" ENDARROW="Default" ENDINCLINATION="-141;9;" ID="Arrow_ID_816334190" SOURCE="ID_226373762" STARTARROW="None" STARTINCLINATION="-192;20;"/>
 <icon BUILTIN="button_ok"/>
 <node COLOR="#338800" CREATED="1683120139366" ID="ID_255513798" MODIFIED="1683120148509" TEXT="Test-Setup mit einfachen int-Intevallen">
@@ -70508,8 +70514,11 @@
 </node>
 </node>
 </node>
-<node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1683120235864" ID="ID_1312143276" MODIFIED="1683120244568" TEXT="Segmentation-Standardf&#xe4;lle">
-<icon BUILTIN="flag-yellow"/>
+<node BACKGROUND_COLOR="#eef0c5" COLOR="#990000" CREATED="1683120235864" ID="ID_1312143276" MODIFIED="1683250859522" TEXT="Segmentation-Standardf&#xe4;lle">
+<icon BUILTIN="pencil"/>
+<node COLOR="#338800" CREATED="1683250843877" ID="ID_608613083" MODIFIED="1683250856171" TEXT="einfache Segmentation mit einem Segment ab 10s">
+<icon BUILTIN="button_ok"/>
+</node>
 </node>
 <node BACKGROUND_COLOR="#eee5c3" COLOR="#990000" CREATED="1683047063010" ID="ID_1142231389" MODIFIED="1683047144754" TEXT="degenerierte F&#xe4;lle">
 <icon BUILTIN="flag-yellow"/>