diff --git a/src/common/query.hpp b/src/common/query.hpp
index e3bd1f537..0794bd4a0 100644
--- a/src/common/query.hpp
+++ b/src/common/query.hpp
@@ -218,12 +218,20 @@ namespace lumiera {
         }
       
       class Builder;
-
-      Query (QueryID qID)
-        : Goal (qID)
+      
+      explicit
+      Query (QueryID typeID)
+        : Goal (typeID)
         , def_(this->buildSyntacticRepresentation())
         { }
       
+      Query (QueryID typeID, string querySpec)
+        : Goal (defineQueryTypeID(typeID.kind))
+        , def_(querySpec)
+        { 
+          REQUIRE (this->getQID().type == typeID.type);
+        }
+      
       friend class Builder;
       
       
@@ -309,7 +317,17 @@ namespace lumiera {
       
       
     public:
+      /** when done with defining or reworking the query,
+       *  the result may be retrieved by type conversion */
+      operator Query<RES>()
+        {
+          return Query<RES>(typeID_, predicateForm_);
+        }
       
+      
+      /** @return a string representation usable for hashing
+       *  @note includes the type parameter of the underlying query
+       */
       string
       asKey()  const
         {
@@ -319,15 +337,34 @@ namespace lumiera {
         }
       
       
+      /** extract an ID term defined as (single) parameter for the given predicate.
+       *  E.g. when using the query "foo(a), bar(b)", \c extractID("bar") returns "b"
+       * @param predicate symbol of the predicate to investigate
+       * @warning preliminary implementation
+       */
       string
       extractID (Symbol predicate)  const
         {
           return lib::query::extractID (predicate, this->predicateForm_);
         }
       
+      
+      /** remove the first term from this query definition,
+       *  which matches the given predicate symbol
+       * @warning preliminary implementation
+       */
+      Builder&
+      removeTerm (Symbol termPredicate)
+        {
+          lib::query::removeTerm(termPredicate, this->predicateForm_);
+          return *this;
+        }
+      
     };
   
   
+  
+  
   template<class RES>
   typename Query<RES>::Builder
   Query<RES>::rebuild()  const
diff --git a/src/proc/asset/pipe.cpp b/src/proc/asset/pipe.cpp
index d1e49c2c1..3ddf6b04b 100644
--- a/src/proc/asset/pipe.cpp
+++ b/src/proc/asset/pipe.cpp
@@ -60,7 +60,7 @@ namespace asset {
   PPipe 
   Pipe::query (Query<Pipe> const& properties)
   { 
-    UNIMPLEMENTED ("maybe provide a direct way to query, based on a predicate string?");//////////////////////////////////TODO
+    //////////////////////////////////////////////////TODO maybe provide a direct way to query, based on a predicate string?
     return Struct::retrieve (properties); 
   }
   
diff --git a/src/proc/asset/struct-factory-impl.hpp b/src/proc/asset/struct-factory-impl.hpp
index b828413c4..2c22b976f 100644
--- a/src/proc/asset/struct-factory-impl.hpp
+++ b/src/proc/asset/struct-factory-impl.hpp
@@ -67,6 +67,7 @@ namespace asset {
   using boost::format;
   
   using lib::Symbol;
+  using util::uNum;
   using util::isnil;
   using util::contains;
   using lumiera::Query;
@@ -88,11 +89,6 @@ namespace asset {
     Symbol genericIdSymbol ("id");
     Symbol seqNrPredicate  ("ord");
     
-    inline uint
-    asNumber (string const& spec)
-    {
-      return abs(std::atoi (spec.c_str()));
-    }        // returns 0 in case of unparseable number
   }
   
   
@@ -130,7 +126,7 @@ namespace asset {
           
           // does the query actually demand the Nth instance/element?
           string seqID = query.extractID (seqNrPredicate);
-          if (!isnil (seqID) && 1 < asNumber(seqID))
+          if (!isnil (seqID) && 1 < uNum(seqID))
             nameID += "."+seqID;
           
           Category cat (STRUCT, StructTraits<STRU>::catFolder());
diff --git a/src/proc/mobject/output-designation.cpp b/src/proc/mobject/output-designation.cpp
index f4f813fe7..582ce02df 100644
--- a/src/proc/mobject/output-designation.cpp
+++ b/src/proc/mobject/output-designation.cpp
@@ -46,6 +46,7 @@
 #include "proc/mobject/output-designation.hpp"
 #include "proc/mobject/output-mapping.hpp"
 #include "proc/config-resolver.hpp"
+#include "lib/util.hpp"
 
 #include <boost/functional/hash.hpp>
 #include <cstdlib>
@@ -56,6 +57,7 @@ using lib::query::removeTerm;
 using lib::query::extractID;
 using proc::ConfigResolver;
 using lib::HashVal;
+using util::uNum;
 
 namespace proc {
 namespace mobject {
@@ -182,18 +184,15 @@ namespace mobject {
     uint
     is_defaults_query_with_channel (Query<asset::Pipe> const& query4pipe)
     {
-      string seqNr = "TODO";//extractID (SEQNR_PREDICATE, query4pipe);////////////////////////////////////////////////////////////////////////////////////////////TODO
-      UNIMPLEMENTED ("Query remolding");////////////////////////////////////////////////////////////////////////////////////////////TODO
-      return abs(std::atoi (seqNr.c_str()));  // also 0 in case of an invalid number
+      string seqNr = query4pipe.extractID (SEQNR_PREDICATE);
+      return uNum (seqNr);  // defaults to 0 in case of an invalid number
     }
     
     Query<asset::Pipe>
     build_corresponding_sourceQuery (Query<asset::Pipe> const& query4pipe)
     {
-      Query<asset::Pipe> srcQuery = query4pipe;
-//    removeTerm (SEQNR_PREDICATE, srcQuery);////////////////////////////////////////////////////////////////////////////////////////////TODO
-      UNIMPLEMENTED ("Query remolding");////////////////////////////////////////////////////////////////////////////////////////////TODO
-      return srcQuery;
+      return query4pipe.rebuild()
+                       .removeTerm (SEQNR_PREDICATE);
     }
   }