Index: TODO
===================================================================
diff -u -r3d4cb79342d1f74cdcc39d6d8b87e9c475f2706a -re756bf87414d3f6376327b3a126e5e8ae619302d
--- TODO	(.../TODO)	(revision 3d4cb79342d1f74cdcc39d6d8b87e9c475f2706a)
+++ TODO	(.../TODO)	(revision e756bf87414d3f6376327b3a126e5e8ae619302d)
@@ -2103,6 +2103,9 @@
 - deactivated automatic namespace path copying for child-objects
 - extended regression test
 
+- added deletion functionality to nsf::mixin
+- moved handling of methodNames of c-cmds to ResolveMethodName()
+- extended regression test
 
 TODO:
 - info method definition for attributes?
Index: generic/nsf.c
===================================================================
diff -u -r8c7cda91db207490f2d401595cec6cf784460bb6 -re756bf87414d3f6376327b3a126e5e8ae619302d
--- generic/nsf.c	(.../nsf.c)	(revision 8c7cda91db207490f2d401595cec6cf784460bb6)
+++ generic/nsf.c	(.../nsf.c)	(revision e756bf87414d3f6376327b3a126e5e8ae619302d)
@@ -1365,10 +1365,11 @@
     referencedObject = GetRegObject(interp, cmd, methodName, methodName1, fromClassNS);
     *regObject = referencedObject;
     *defObject = referencedObject;
+    *methodName1 = Tcl_GetCommandName(interp, cmd);
     if (referencedObject == NULL) {
       /* 
        * The cmd was not registered on an object or class, but we
-       * still report back the cmd (might be e.g. a primitive cmd.
+       * still report back the cmd (might be e.g. a primitive cmd).
        */
     }
   } else {
@@ -12263,6 +12264,9 @@
 static int
 ListCmdParams(Tcl_Interp *interp, Tcl_Command cmd, CONST char *methodName, int withVarnames) {
   Proc *procPtr = GetTclProcFromCommand(cmd);
+
+  assert(methodName);
+
   if (procPtr) {
     NsfParamDefs *paramDefs = procPtr ? ParamDefsGet((Tcl_Command)procPtr->cmdPtr) : NULL;
     Tcl_Obj *list;
@@ -12360,16 +12364,7 @@
 	Tcl_DStringAppend(dsPtr, cmdPtr->nsPtr->fullName, -1);
       }
       Tcl_DStringAppend(dsPtr, "::", 2);
-           
-      if (methodName != NULL) {
-	  Tcl_DStringAppend(dsPtr, methodName, -1);
-      } else {
-	  /* 
-	     This branch is enter for C-implemented commands,
-	     such as ::nsf::xotclnext
-          */
-	  Tcl_DStringAppend(dsPtr, Tcl_GetCommandName(interp,cmd), -1);
-      }
+      Tcl_DStringAppend(dsPtr, methodName, -1);
       
       /*fprintf(stderr,"Looking up ::nsf::parametersyntax(%s) ...\n",Tcl_DStringValue(dsPtr));*/
       parameterSyntaxObj = Tcl_GetVar2Ex(interp, "::nsf::parametersyntax", 
@@ -12467,6 +12462,8 @@
 	   CONST char *methodName, Tcl_Command cmd,
            int subcmd, int withPer_object) {
 
+  assert(methodName);
+
   /*fprintf(stderr, "ListMethod %s %s cmd %p subcmd %d per-object %d\n",
     ObjectName(regObject), methodName, cmd, subcmd, withPer_object);*/
 
@@ -14586,8 +14583,8 @@
   NsfClassOpt *clopt = NULL, *nclopt = NULL;
   int i;
 
-  /* fprintf(stderr, "NsfRelationCmd %s rel=%d val='%s'\n",
-     ObjectName(object), relationtype, valueObj ? ObjStr(valueObj) : "NULL");*/
+  /*fprintf(stderr, "NsfRelationCmd %s rel=%d val='%s'\n",
+    ObjectName(object), relationtype, valueObj ? ObjStr(valueObj) : "NULL");*/
 
   if (relationtype == RelationtypeClass_mixinIdx ||
       relationtype == RelationtypeClass_filterIdx) {
@@ -16867,8 +16864,8 @@
   cmd = ResolveMethodName(interp, object->nsPtr, methodNameObj,
 			  dsPtr, &regObject, &defObject, &methodName1, &fromClassNS);
   /*fprintf(stderr,
-	  "NsfObjInfoMethodMethod method %s object %p regObject %p defObject %p fromClass %d\n",
-	  ObjStr(methodNameObj), object,regObject,defObject,fromClassNS);*/
+	  "NsfObjInfoMethodMethod method %s / %s object %p regObject %p defObject %p fromClass %d\n",
+	  ObjStr(methodNameObj), methodName1, object,regObject,defObject,fromClassNS);*/
   result = ListMethod(interp,
 		      regObject ? regObject : object,
 		      defObject ? defObject : object,
@@ -17121,8 +17118,8 @@
   cmd = ResolveMethodName(interp, class->nsPtr, methodNameObj,
 			  dsPtr, &regObject, &defObject, &methodName1, &fromClassNS);
   /*fprintf(stderr,
-	  "NsfClassInfoMethodMethod object %p regObject %p defObject %p fromClass %d cmd %p\n",
-	  &class->object,regObject,defObject,fromClassNS, cmd);*/
+	  "NsfClassInfoMethodMethod object %p regObject %p defObject %p fromClass %d cmd %p method %s\n",
+	  &class->object,regObject,defObject,fromClassNS, cmd, methodName1);*/
   result = ListMethod(interp,
 		      regObject ? regObject : &class->object,
 		      defObject ? defObject : &class->object,
Index: generic/nsf.tcl
===================================================================
diff -u -r8c7cda91db207490f2d401595cec6cf784460bb6 -re756bf87414d3f6376327b3a126e5e8ae619302d
--- generic/nsf.tcl	(.../nsf.tcl)	(revision 8c7cda91db207490f2d401595cec6cf784460bb6)
+++ generic/nsf.tcl	(.../nsf.tcl)	(revision e756bf87414d3f6376327b3a126e5e8ae619302d)
@@ -40,7 +40,10 @@
   #
   # ::nsf::mixin 
   #
-  # provide a similar interface as for ::nsf::method, ::nsf::alias, ...
+  # Provide a similar interface as for ::nsf::method, ::nsf::alias,
+  # etc..  Semantically, ::nsf::mxiin behaves like a "mixin add", but
+  # can be used as well for deleting the mixin list (empty last
+  # argument).
   #
 
   set ::nsf::parametersyntax(::nsf::mixin) "object ?-per-object? classes"
@@ -52,9 +55,14 @@
     } else {
       set rel "class-mixin"
     }
-    set oldSetting [::nsf::relation $object $rel]
-    # use uplevel to avoid namespace surprises
-    uplevel [list ::nsf::relation $object $rel [linsert $oldSetting end $args]]
+    puts stderr LL=[llength $args]-$args
+    if {[lindex $args 0] ne ""} {
+      set oldSetting [::nsf::relation $object $rel]
+      # use uplevel to avoid namespace surprises
+      uplevel [list ::nsf::relation $object $rel [linsert $oldSetting 0 $args]]
+    } else {
+      uplevel [list ::nsf::relation $object $rel ""]
+    }
   }
 
   #
Index: generic/predefined.h
===================================================================
diff -u -r8c7cda91db207490f2d401595cec6cf784460bb6 -re756bf87414d3f6376327b3a126e5e8ae619302d
--- generic/predefined.h	(.../predefined.h)	(revision 8c7cda91db207490f2d401595cec6cf784460bb6)
+++ generic/predefined.h	(.../predefined.h)	(revision e756bf87414d3f6376327b3a126e5e8ae619302d)
@@ -21,8 +21,11 @@
 "set rel \"object-mixin\"\n"
 "set args [lrange $args 1 end]} else {\n"
 "set rel \"class-mixin\"}\n"
+"puts stderr LL=[llength $args]-$args\n"
+"if {[lindex $args 0] ne \"\"} {\n"
 "set oldSetting [::nsf::relation $object $rel]\n"
-"uplevel [list ::nsf::relation $object $rel [linsert $oldSetting end $args]]}\n"
+"uplevel [list ::nsf::relation $object $rel [linsert $oldSetting 0 $args]]} else {\n"
+"uplevel [list ::nsf::relation $object $rel \"\"]}}\n"
 "::nsf::provide_method autoname {::nsf::alias autoname ::nsf::methods::object::autoname}\n"
 "::nsf::provide_method exists   {::nsf::alias  exists ::nsf::methods::object::exists}\n"
 "proc ::nsf::exithandler {args} {\n"
Index: tests/info-method.test
===================================================================
diff -u -rb8b81d5258a35f294599bb755a0cc15cf363972b -re756bf87414d3f6376327b3a126e5e8ae619302d
--- tests/info-method.test	(.../info-method.test)	(revision b8b81d5258a35f294599bb755a0cc15cf363972b)
+++ tests/info-method.test	(.../info-method.test)	(revision e756bf87414d3f6376327b3a126e5e8ae619302d)
@@ -406,4 +406,7 @@
   ? {::nx::Object info method parametersyntax method} "name arguments ?-returns value? body ?-precondition value? ?-postcondition value?"
   # a forwarder to ::nsf::relation; definition comes via ::nsf::parametersyntax
   ? {::nx::Object info method parametersyntax mixin} "?classes?|?add class?|?delete class?"
+
+  ? {::nx::Object info method parametersyntax ::nx::next} "?arguments?"
+  ? {::nx::Object info method parametersyntax ::nsf::xotclnext} "?--noArgs? ?arg ...?"
 }
\ No newline at end of file
Index: tests/interceptor-slot.test
===================================================================
diff -u -r84c5ee62a46e8fab7b9cc481c87290d387baced9 -re756bf87414d3f6376327b3a126e5e8ae619302d
--- tests/interceptor-slot.test	(.../interceptor-slot.test)	(revision 84c5ee62a46e8fab7b9cc481c87290d387baced9)
+++ tests/interceptor-slot.test	(.../interceptor-slot.test)	(revision e756bf87414d3f6376327b3a126e5e8ae619302d)
@@ -22,7 +22,21 @@
 C mixin delete M2
 ? {c1 info precedence} "::M ::C ::nx::Object"
 C mixin delete M
+? {C info mixin classes} ""
+C mixin ::M
+C mixin {}
+? {C info mixin classes} ""
 
+#
+# test nsf::mixin interface
+#
+::nsf::mixin C ::M
+? {C info mixin classes} "::M"
+::nsf::mixin C ::M2
+? {C info mixin classes} "::M2 ::M"
+::nsf::mixin C ""
+? {C info mixin classes} ""
+
 # per-object mixins
 ? {c1 info precedence} "::C ::nx::Object"
 c1 mixin add M