diff --git a/src/proc/mobject/placement.cpp b/src/proc/mobject/placement.cpp
index fd2d02e9f..1b6e4c14d 100644
--- a/src/proc/mobject/placement.cpp
+++ b/src/proc/mobject/placement.cpp
@@ -69,6 +69,16 @@ namespace mobject {
   }
   
   
+  bool
+  isSameDef (PlacementMO const& pl1, PlacementMO const& pl2)
+  {
+    return pl1.getID() == pl2.getID()
+        || pl1.chain == pl2.chain
+        ;
+  }
+
+  
+  
 
 
 } // namespace mobject
diff --git a/src/proc/mobject/placement.hpp b/src/proc/mobject/placement.hpp
index 703ccc52a..1ebb966ac 100644
--- a/src/proc/mobject/placement.hpp
+++ b/src/proc/mobject/placement.hpp
@@ -240,14 +240,26 @@ namespace mobject {
     };
   
   
-  string
-  format_PlacementID (Placement<MObject> const&) ;
-  
-  
   /** @todo cleanup uses of ref-to-placement. See Ticket #115 */
   typedef Placement<MObject> PlacementMO; 
   typedef Placement<MObject> PMO; 
+  
+  
+  
+  /* == free functions == */
 
-
+  string
+  format_PlacementID (PlacementMO const&) ;
+  
+  
+  /** compare the properties of placement
+   *  @return \c true if all the LocatingPin entries
+   *          in both placements are semantically equivalent.
+   */
+  bool
+  isSameDef (PlacementMO const&, PlacementMO const&);
+  
+  
+  
 } // namespace mobject
 #endif
diff --git a/src/proc/mobject/session/locatingpin.cpp b/src/proc/mobject/session/locatingpin.cpp
index 9191c818f..f4e7ce954 100644
--- a/src/proc/mobject/session/locatingpin.cpp
+++ b/src/proc/mobject/session/locatingpin.cpp
@@ -146,8 +146,8 @@ namespace session {
   LocatingPin::Pipe
   LocatingPin::LocatingSolution::getPipe()
   {
-    UNIMPLEMENTED ("get effective Pipe of Solution");
-    return Pipe (); 
+    TODO ("implement Placement LocatingSolution");
+    return asset::Pipe::query ("pipe(master)");  // yet another idiotic dummy
   }
   
   
diff --git a/src/proc/mobject/session/locatingpin.hpp b/src/proc/mobject/session/locatingpin.hpp
index 99d2c92b1..50e0160e3 100644
--- a/src/proc/mobject/session/locatingpin.hpp
+++ b/src/proc/mobject/session/locatingpin.hpp
@@ -167,8 +167,20 @@ protected:
             bool still_to_solve (); 
             
           };
+        
+        friend bool operator== (LocatingPin const&, LocatingPin const&);
+        
       };
       
+    
+    /** check for equivalent definition of a complete locating chain */
+    
+    inline bool
+    operator== (LocatingPin const& pin1, LocatingPin const& pin2)
+    {
+//////////////////////////////////////////////////////////////////////////////////////////////////////TICKET #511  really implement equivalence relation!          
+      return pin1.resolve().first == pin2.resolve().first;
+    }