diff --git a/src/proc/engine/job-planning.hpp b/src/proc/engine/job-planning.hpp
index 859258aab..abe77c9d8 100644
--- a/src/proc/engine/job-planning.hpp
+++ b/src/proc/engine/job-planning.hpp
@@ -114,10 +114,16 @@ namespace engine {
       
       /** integrate another chain of prerequisites into the current evaluation line.
        *  Further evaluation will start to visit prerequisites from the new starting point,
-       *  and return to the current evaluation chain later on exhaustion of the side chain. */
+       *  and return to the current evaluation chain later on exhaustion of the side chain.
+       *  Especially in case the current evaluation is empty or already exhausted, the
+       *  new starting point effectively replaces the current evaluation point */
       friend void
       integrate (JobPlanning const& newStartingPoint, JobPlanning& existingPlan)
       {
+        if (isnil (existingPlan.plannedOperations_))
+          { // current evaluation is exhausted: switch to new starting point
+            existingPlan.point_to_calculate_ = newStartingPoint.point_to_calculate_;
+          }
         existingPlan.plannedOperations_.push (newStartingPoint.plannedOperations_);
       }
       
diff --git a/src/proc/engine/job-ticket.hpp b/src/proc/engine/job-ticket.hpp
index a6e9e6e52..b38df691c 100644
--- a/src/proc/engine/job-ticket.hpp
+++ b/src/proc/engine/job-ticket.hpp
@@ -130,6 +130,7 @@ using util::isnil;
         }
       
       
+      ExplorationState startExploration()                      const;
       ExplorationState discoverPrerequisites (uint channelNr)  const;
       
       Job createJobFor (FrameCoord coordinates);
@@ -234,6 +235,17 @@ using util::isnil;
   
   
   
+  inline JobTicket::ExplorationState
+  JobTicket::startExploration()  const
+  {
+    UNIMPLEMENTED ("somehow build a self-referential pseudo-prerequisite, and seed an ExplorationState with that");
+    /////////////////////TODO problem is: we need an JobTicket::Prerequisite instance, where the descriptor points to "self" (this JobTicket)
+    /////////////////////TODO           : but this instance needs to reside somewhere at a safe location, since we want to embed an LinkedElements-iterator
+    /////////////////////TODO           : into the ExplorationState. And obviously we do not want that instance in each JobTicket, only in the top level ones
+  }
+  
+  
+  
   inline JobTicket::ExplorationState
   JobTicket::discoverPrerequisites (uint channelNr)  const
   {