diff --git a/src/proc/control/command-argument-holder.hpp b/src/proc/control/command-argument-holder.hpp
index f707efe4a..c2bcbb0f7 100644
--- a/src/proc/control/command-argument-holder.hpp
+++ b/src/proc/control/command-argument-holder.hpp
@@ -140,6 +140,12 @@ namespace control {
           return arguments_->isValid();
         }
       
+      virtual bool isCaptured() const
+        {
+          return memento_->isValid();
+        }
+
+      
       
       /** assign a new parameter tuple to this */
       virtual void bindArguments (Arguments& args)
diff --git a/src/proc/control/command-closure.hpp b/src/proc/control/command-closure.hpp
index da173bb8d..73b94ceda 100644
--- a/src/proc/control/command-closure.hpp
+++ b/src/proc/control/command-closure.hpp
@@ -127,14 +127,11 @@ namespace control {
       virtual ~CmdClosure() {}
       
       virtual operator string() const                    =0;
-      
-      virtual bool isValid ()   const                    =0;
-      
-      virtual void bindArguments (Arguments&)            =0;
-      
-      virtual void invoke (CmdFunctor const&)            =0;
-      
-      virtual PClo createClone (TypedAllocationManager&) =0;
+      virtual bool isValid ()   const                    =0;      ///< does this closure hold a valid argument tuple?
+      virtual bool isCaptured () const                   =0;      ///< does this closure hold captured UNDO state?
+      virtual void bindArguments (Arguments&)            =0;      ///< store a set of parameter values within this closure
+      virtual void invoke (CmdFunctor const&)            =0;      ///< invoke functor using the stored parameter values
+      virtual PClo createClone (TypedAllocationManager&) =0;      ///< create clone allocation without disclosing concrete type
     };
   
   
@@ -271,7 +268,8 @@ namespace control {
         }
       
       
-      bool isValid ()  const { return true; }
+      bool isValid ()   const { return true; }
+      bool isCaptured() const { return false; }
       
       
       /// Supporting equality comparisons...
diff --git a/src/proc/control/command-impl.cpp b/src/proc/control/command-impl.cpp
index 79e5cfddd..b73573091 100644
--- a/src/proc/control/command-impl.cpp
+++ b/src/proc/control/command-impl.cpp
@@ -50,13 +50,6 @@ namespace control {
   /////////////////////////////////////////TODO: is this impl file actually necessary??
 
   
-  bool
-  CommandImpl::hasUndoState (CmdClosure const& closure)
-  {
-    UNIMPLEMENTED ("how the hell do we get at the memento-captured state???");
-//    REQUIRE (INSTANCEOF (ArgumentHolder, &closure));
-//    return static_cast<ArgumentHolder const&> (closure).canUndo();
-  }
   
   
   
diff --git a/src/proc/control/command-impl.hpp b/src/proc/control/command-impl.hpp
index 561a10331..92871a509 100644
--- a/src/proc/control/command-impl.hpp
+++ b/src/proc/control/command-impl.hpp
@@ -183,7 +183,7 @@ namespace control {
       bool
       canUndo()  const    ///< state check: has undo state been captured? 
         {
-          return isValid() && hasUndoState(*pClo_);
+          return isValid() && pClo_->isCaptured();
         }
       
       
@@ -191,8 +191,6 @@ namespace control {
       
     private:
       
-      static bool hasUndoState (CmdClosure const&);
-      
     };