diff --git a/src/common/util.hpp b/src/common/util.hpp
index 00c7bb638..402cbb435 100644
--- a/src/common/util.hpp
+++ b/src/common/util.hpp
@@ -31,10 +31,10 @@
 
 
 
-namespace util
-  {
+namespace util {
+  
   using std::string;
-
+  
   
   template <class NUM>
   inline int
@@ -43,7 +43,7 @@ namespace util
     return (n==0)? 0 :((n<0)? -1:+1 );
   }
   
-
+  
   /** a family of util functions providing a "no value whatsoever" test.
       Works on strings and all STL containers, includes NULL test for pointers */
   template <class CONT>
@@ -65,7 +65,7 @@ namespace util
   {
     return !pCStr || 0 == std::strlen(pCStr);
   }
-
+  
   
   /** cut a numeric value to be >=0 */
   template <typename NUM>
@@ -100,7 +100,7 @@ namespace util
   }
   
   /** shortcut for brute-force containment test
-   *  in any sequencial container */
+   *  in any sequential container */
   template <typename SEQ>
   inline bool 
   contains (SEQ& cont, typename SEQ::const_reference val)
@@ -112,7 +112,7 @@ namespace util
   }
   
   /** shortcut for removing all copies of an Element
-   *  in any sequencial collection */
+   *  in any sequential collection */
   template <typename SEQ>
   inline typename SEQ::iterator 
   removeall (SEQ& coll, typename SEQ::value_type& val)
@@ -187,7 +187,7 @@ namespace util
   
   /** produce an identifier based on the given string.
    *  remove non-standard-chars, reduce sequences of punctuation 
-   *  and whitespace to single underscores. The sanitized string
+   *  and whitespace to single underscores. The sanitised string
    *  will start with an alphanumeric character.
    * 
    * @par Example Conversions
@@ -215,7 +215,7 @@ namespace util
   {
     return org.c_str();
   }
-
+  
   
 } // namespace util
 
@@ -223,7 +223,7 @@ namespace util
 
  /* === some common macro definitions === */
 
-/** supress "warning: unused variable" on vars, which are
+/** suppress "warning: unused variable" on vars, which are
  *  introduced into a scope because of some sideeffect, i.e. Locking
  */
 #define SIDEEFFECT __attribute__ ((unused));
diff --git a/src/lumiera/subsys.hpp b/src/lumiera/subsys.hpp
index df7db5255..ad6b37534 100644
--- a/src/lumiera/subsys.hpp
+++ b/src/lumiera/subsys.hpp
@@ -48,6 +48,7 @@
 #include "lumiera/option.hpp"
 
 #include <boost/noncopyable.hpp>
+#include <boost/tr1/functional.hpp>
 //#include <boost/scoped_ptr.hpp>
 //#include <string>
 #include <vector>
@@ -59,6 +60,7 @@ namespace lumiera {
   using std::string;
 //  using boost::scoped_ptr;
   using boost::noncopyable;
+  using std::tr1::function;
   
   
   
@@ -71,7 +73,7 @@ namespace lumiera {
     : private noncopyable
     {
     public:
-      typedef void (SigTerm)(Error*); ///////////////////TODO better use Glib-- Signal type?
+      typedef function<void(Error*)> SigTerm;
       
       virtual ~Subsys();
       
@@ -81,20 +83,23 @@ namespace lumiera {
       Subsys& depends (Subsys& prereq);
       
       
-      /** a query to run on the application option state
-       *  to determine if this subsystem should be activated. */
+      /** query application option state to determine 
+       *  if this subsystem should be activated. */
       virtual bool shouldStart (lumiera::Option&)  =0;
       
       
       /** how to start up this subsystem. Failure to start up
        *  usually terminates the whole application. When this subsystem
        *  ceases to work, it must assure to activate the given signal.
-       *  @param termination to be signalled by the subsystem. 
+       *  @param options may be influencing the operation mode 
+       *  @param termination to be signalled by the subsystem.
+       *  @warning termination must be signalled reliably.  
        *  @return \c true if actually started. */
-      virtual bool start (lumiera::Option&, SigTerm termination)  =0;
+      virtual bool start (lumiera::Option&, SigTerm)  =0;
       
       
       /** initiate termination of this subsystem.
+       *  may be called repeatedly any time...
        *  @warning must not block nor throw. */
       virtual void triggerShutdown ()  throw() =0;
       
diff --git a/src/proc/mobject/session/defsregistry.hpp b/src/proc/mobject/session/defsregistry.hpp
index 75068ec92..2973b85e7 100644
--- a/src/proc/mobject/session/defsregistry.hpp
+++ b/src/proc/mobject/session/defsregistry.hpp
@@ -173,7 +173,7 @@ namespace mobject
         };
         
         
-      // static vars to organize one Table Slot per type....
+      // static vars to organise one Table Slot per type....
       template<class TAR>
       size_t Slot<TAR>::index (0);