Index: TODO
===================================================================
diff -u -rede10bf0265c3943458771665317aa0c12971900 -r2cca652c92b1933dd1b27f002a4c4886730f34f1
--- TODO	(.../TODO)	(revision ede10bf0265c3943458771665317aa0c12971900)
+++ TODO	(.../TODO)	(revision 2cca652c92b1933dd1b27f002a4c4886730f34f1)
@@ -4039,6 +4039,13 @@
 - handle cyclical superclassclass dependencies during object system finalize
 - extend regression test
 
+nx.tcl:
+- set multiplicty for mixins and filters by default from 1..n to 0..n
+  to avoid error messages, when e.g. empty mixin lists are configured.
+  Setting emtpy mixin-lists is strictly speaking not necessary,
+  but this eases the code in cases the lists are sometimes empty.
+
+
 ========================================================================
 TODO:
 
Index: library/nx/nx.tcl
===================================================================
diff -u -r489b8b8e5f1ce1522121dcee270f18396c380071 -r2cca652c92b1933dd1b27f002a4c4886730f34f1
--- library/nx/nx.tcl	(.../nx.tcl)	(revision 489b8b8e5f1ce1522121dcee270f18396c380071)
+++ library/nx/nx.tcl	(.../nx.tcl)	(revision 2cca652c92b1933dd1b27f002a4c4886730f34f1)
@@ -1322,7 +1322,7 @@
 
   createBootstrapVariableSlots ::nx::RelationSlot {
     {accessor true}
-    {multiplicity 1..n}
+    {multiplicity 0..n}
   }
 
   RelationSlot protected method init {} {
Index: tests/info-method.test
===================================================================
diff -u -r9124d823b4eb4a8b5969b9fa1b6eab7252ba83b4 -r2cca652c92b1933dd1b27f002a4c4886730f34f1
--- tests/info-method.test	(.../info-method.test)	(revision 9124d823b4eb4a8b5969b9fa1b6eab7252ba83b4)
+++ tests/info-method.test	(.../info-method.test)	(revision 2cca652c92b1933dd1b27f002a4c4886730f34f1)
@@ -696,7 +696,7 @@
   ? {C info parameter syntax} "?-a value? ?-b value? ?-volatile? ?-properties value? ?-noinit? ?-mixin mixinreg ...? ?-class class? ?-filter filterreg ...? ?__initcmd?"
   ? {C info parameter syntax a} "?-a value?"
 
-  ? {C info parameter definition} "-a {-b 1} -volatile:alias,noarg -properties:alias,method=::nx::internal::addProperties -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:mixinreg,alias,1..n -class:class,alias,method=::nsf::methods::object::class -filter:filterreg,alias,1..n __initcmd:initcmd,optional,noleadingdash"
+  ? {C info parameter definition} "-a {-b 1} -volatile:alias,noarg -properties:alias,method=::nx::internal::addProperties -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:mixinreg,alias,0..n -class:class,alias,method=::nsf::methods::object::class -filter:filterreg,alias,0..n __initcmd:initcmd,optional,noleadingdash"
 
   ? {C info parameter list} "-a -b -volatile -properties -noinit -mixin -class -filter __initcmd"
   ? {C info parameter names} "a b volatile properties noinit mixin class filter __initcmd"
Index: tests/parameters.test
===================================================================
diff -u -r489b8b8e5f1ce1522121dcee270f18396c380071 -r2cca652c92b1933dd1b27f002a4c4886730f34f1
--- tests/parameters.test	(.../parameters.test)	(revision 489b8b8e5f1ce1522121dcee270f18396c380071)
+++ tests/parameters.test	(.../parameters.test)	(revision 2cca652c92b1933dd1b27f002a4c4886730f34f1)
@@ -274,7 +274,7 @@
   C create c1
  
   ? {C eval :objectparameter} \
-      "-a -b:boolean {-c 1} -volatile:alias,noarg -properties:alias,method=::nx::internal::addProperties -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:mixinreg,alias,1..n -class:class,alias,method=::nsf::methods::object::class -filter:filterreg,alias,1..n __initcmd:initcmd,optional,noleadingdash"
+      "-a -b:boolean {-c 1} -volatile:alias,noarg -properties:alias,method=::nx::internal::addProperties -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:mixinreg,alias,0..n -class:class,alias,method=::nsf::methods::object::class -filter:filterreg,alias,0..n __initcmd:initcmd,optional,noleadingdash"
 
   ? {c1 eval :objectparameter} \
       "::c1: unable to dispatch method 'objectparameter'"
@@ -305,7 +305,7 @@
       "::D::slot::d ::C::slot::a ::C::slot::b ::C::slot::c"
   
   ? {D eval :objectparameter} \
-      "-d:required -a -b:boolean {-c 1} -volatile:alias,noarg -properties:alias,method=::nx::internal::addProperties -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:mixinreg,alias,1..n -class:class,alias,method=::nsf::methods::object::class -filter:filterreg,alias,1..n __initcmd:initcmd,optional,noleadingdash"
+      "-d:required -a -b:boolean {-c 1} -volatile:alias,noarg -properties:alias,method=::nx::internal::addProperties -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:mixinreg,alias,0..n -class:class,alias,method=::nsf::methods::object::class -filter:filterreg,alias,0..n __initcmd:initcmd,optional,noleadingdash"
 }
 
 #######################################################
@@ -334,29 +334,29 @@
   D mixin M
 
   ? {D eval :objectparameter} \
-      "-b -m1 -m2 -d:required -a {-c 1} -volatile:alias,noarg -properties:alias,method=::nx::internal::addProperties -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:mixinreg,alias,1..n -class:class,alias,method=::nsf::methods::object::class -filter:filterreg,alias,1..n __initcmd:initcmd,optional,noleadingdash" \
+      "-b -m1 -m2 -d:required -a {-c 1} -volatile:alias,noarg -properties:alias,method=::nx::internal::addProperties -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:mixinreg,alias,0..n -class:class,alias,method=::nsf::methods::object::class -filter:filterreg,alias,0..n __initcmd:initcmd,optional,noleadingdash" \
     "mixin added"
 
   M mixin M2
 
   ? {D eval :objectparameter} \
-      "-b2 -b -m1 -m2 -d:required -a {-c 1} -volatile:alias,noarg -properties:alias,method=::nx::internal::addProperties -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:mixinreg,alias,1..n -class:class,alias,method=::nsf::methods::object::class -filter:filterreg,alias,1..n __initcmd:initcmd,optional,noleadingdash" \
+      "-b2 -b -m1 -m2 -d:required -a {-c 1} -volatile:alias,noarg -properties:alias,method=::nx::internal::addProperties -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:mixinreg,alias,0..n -class:class,alias,method=::nsf::methods::object::class -filter:filterreg,alias,0..n __initcmd:initcmd,optional,noleadingdash" \
     "transitive mixin added"
   D mixin ""
   #we should have again the old interface
 
   ? {D eval :objectparameter} \
-      "-d:required -a -b:boolean {-c 1} -volatile:alias,noarg -properties:alias,method=::nx::internal::addProperties -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:mixinreg,alias,1..n -class:class,alias,method=::nsf::methods::object::class -filter:filterreg,alias,1..n __initcmd:initcmd,optional,noleadingdash"
+      "-d:required -a -b:boolean {-c 1} -volatile:alias,noarg -properties:alias,method=::nx::internal::addProperties -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:mixinreg,alias,0..n -class:class,alias,method=::nsf::methods::object::class -filter:filterreg,alias,0..n __initcmd:initcmd,optional,noleadingdash"
 
   C mixin M
   ? {D eval :objectparameter} \
-      "-b2 -b -m1 -m2 -d:required -a {-c 1} -volatile:alias,noarg -properties:alias,method=::nx::internal::addProperties -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:mixinreg,alias,1..n -class:class,alias,method=::nsf::methods::object::class -filter:filterreg,alias,1..n __initcmd:initcmd,optional,noleadingdash" \
+      "-b2 -b -m1 -m2 -d:required -a {-c 1} -volatile:alias,noarg -properties:alias,method=::nx::internal::addProperties -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:mixinreg,alias,0..n -class:class,alias,method=::nsf::methods::object::class -filter:filterreg,alias,0..n __initcmd:initcmd,optional,noleadingdash" \
     "mixin added"
   C mixin ""
   #we should have again the old interface
   
   ? {D eval :objectparameter} \
-      "-d:required -a -b:boolean {-c 1} -volatile:alias,noarg -properties:alias,method=::nx::internal::addProperties -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:mixinreg,alias,1..n -class:class,alias,method=::nsf::methods::object::class -filter:filterreg,alias,1..n __initcmd:initcmd,optional,noleadingdash" 
+      "-d:required -a -b:boolean {-c 1} -volatile:alias,noarg -properties:alias,method=::nx::internal::addProperties -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:mixinreg,alias,0..n -class:class,alias,method=::nsf::methods::object::class -filter:filterreg,alias,0..n __initcmd:initcmd,optional,noleadingdash" 
 }
 
 #######################################################
@@ -1845,7 +1845,7 @@
 
   ? {C info slot objects -closure} "::C::slot::a1 ::nx::Object::slot::volatile ::nx::Object::slot::properties ::nx::Object::slot::noinit ::nx::Object::slot::mixin ::nx::Object::slot::__initcmd ::nx::Object::slot::class ::nx::Object::slot::filter"
 
-  ? {C eval :objectparameter} "-a1 -volatile:alias,noarg -properties:alias,method=::nx::internal::addProperties -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:mixinreg,alias,1..n -class:class,alias,method=::nsf::methods::object::class -filter:filterreg,alias,1..n __initcmd:initcmd,optional,noleadingdash"
+  ? {C eval :objectparameter} "-a1 -volatile:alias,noarg -properties:alias,method=::nx::internal::addProperties -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:mixinreg,alias,0..n -class:class,alias,method=::nsf::methods::object::class -filter:filterreg,alias,0..n __initcmd:initcmd,optional,noleadingdash"
 
   #
   # invalidate object parameter and expect that the per-class mixin
@@ -1859,7 +1859,7 @@
 
   ? {C info slot objects -closure} "::C::slot::a1 ::nx::Object::slot::volatile ::nx::Object::slot::properties ::nx::Object::slot::noinit ::nx::Object::slot::mixin ::nx::Object::slot::__initcmd ::nx::Object::slot::class ::nx::Object::slot::filter"
 
-  ? {C eval :objectparameter} "-a1 -volatile:alias,noarg -properties:alias,method=::nx::internal::addProperties -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:mixinreg,alias,1..n -class:class,alias,method=::nsf::methods::object::class -filter:filterreg,alias,1..n __initcmd:initcmd,optional,noleadingdash"
+  ? {C eval :objectparameter} "-a1 -volatile:alias,noarg -properties:alias,method=::nx::internal::addProperties -noinit:alias,method=::nsf::methods::object::noinit,noarg -mixin:mixinreg,alias,0..n -class:class,alias,method=::nsf::methods::object::class -filter:filterreg,alias,0..n __initcmd:initcmd,optional,noleadingdash"
 
   # should not require b1
   ? {C create c2} ::c2