Index: TODO
===================================================================
diff -u -N -re0419345b49587b5738f87c6d828dfc5ae4b3276 -r3be87f20ac5f89fac33e2db3b95e80c9adfc92d9
--- TODO	(.../TODO)	(revision e0419345b49587b5738f87c6d828dfc5ae4b3276)
+++ TODO	(.../TODO)	(revision 3be87f20ac5f89fac33e2db3b95e80c9adfc92d9)
@@ -4574,25 +4574,24 @@
   instead of 
      o1 info lookup configure syntax
 
-- traits: added ability to trun on verbosity for traits
+- traits: added ability to turn on verbosity for traits
   by using
      nx::configure trait-verbosity on|off
 
 nx.tcl:
 - renamed variable option "-config" to "-configurable"
   to make its intention clearer
 
+- changed multiplicity of mixin, object-mixin, filter, object-filter 
+  from 1..n to 0..n; rationale: when one has a list of eg. mixins,
+  which should be passed, one has to test for the length before
+  passing it, otherwise the empty list would generate an error.
+  Allowing 0..n makes the usage simpler and the program shorter.
 
+
 ========================================================================
 TODO:
 
-- reconsider
-  #? {c1 cget -mixin} ""
-  ? {c1 cget -object-mixin} ""
-
-- reconsider lower multiplicity on 
-  -object-mixin, -mixin...
-
 - handling of "required" in reconfigure (see 
   parameter-object-mixin-dependency in parameters.test)
 - handling of recreate (see regression test for class-level properties)