Index: library/lib/nx-traits.tcl
===================================================================
diff -u -r8c8980c36802cc5e71f8a1713945e7655a5a480a -rd31c271afb2488abafa0642b07538a3e62106130
--- library/lib/nx-traits.tcl	(.../nx-traits.tcl)	(revision 8c8980c36802cc5e71f8a1713945e7655a5a480a)
+++ library/lib/nx-traits.tcl	(.../nx-traits.tcl)	(revision d31c271afb2488abafa0642b07538a3e62106130)
@@ -1,5 +1,5 @@
 package require nx
-package provide nx::trait 0.2
+package provide nx::trait 0.3
 
 # @package nx::trait
 # 
@@ -39,6 +39,32 @@
 #
 namespace eval ::nx::trait {}
 
+#
+# nx::trait::provide and nx::trait::require implement the basic
+# loading mechanism for traits
+#
+nsf::proc nx::trait::provide {traitName script} {
+  set ::nsf::traitIndex($traitName) [list script $script]
+}
+
+nsf::proc nx::trait::require {traitName} {
+  if {[::nsf::object::exists $traitName]} {return}
+  set key ::nsf::traitIndex($traitName)
+  if {[info exists $key]} {
+    array set "" [set $key]
+    if {$(script) ne ""} {
+      eval $(script)
+
+    }
+  }
+  if {[::nsf::object::exists $traitName]} {return}
+  error "cannot require trait $traitName, trait unknown"
+}
+
+#
+# The function nx::trait::add adds the methods defined in the
+# specified trait to the obj/class provided as first argument.
+#
 nsf::proc nx::trait::add {obj -per-object:switch traitName {nameMap ""}} {
   array set map $nameMap
   foreach m [$traitName info methods -callprotection all] {
@@ -54,6 +80,10 @@
   }
 }
 
+#
+# The function nx::trait::checkObject checks, whether the target
+# object has the method defined that the trait requires.
+#
 nsf::proc nx::trait::checkObject {obj traitName} {
   foreach m [$traitName requiredMethods] {
     #puts "$m ok? [$obj info methods -closure $m]"
@@ -62,6 +92,11 @@
     }
   }
 }
+
+#
+# The function nx::trait::checkClass checks, whether the target
+# class has the method defined that the trait requires.
+#
 nsf::proc nx::trait::checkClass {obj traitName} {
   foreach m [$traitName requiredMethods] {
     #puts "$m ok? [$obj info methods -closure $m]"
@@ -71,31 +106,43 @@
   }
 }
 
+#
+# The require methods for traits extend the predefined ensemble with
+# trait-specific subcommands.
+#
 nx::Class public method "require trait" {traitName {nameMap ""}} {
   # adding a trait to a class
+  nx::trait::require $traitName
   nx::trait::checkClass [self] $traitName
   nx::trait::add [self] $traitName $nameMap  
 }
 
 nx::Class public method "require class trait" {traitName {nameMap ""}} {
   # adding a trait to the class object
+  nx::trait::require $traitName
   nx::trait::checkObject [self] $traitName
   nx::trait::add [self] -per-object $traitName $nameMap  
 }
 
 nx::Object public method "require trait" {traitName {nameMap ""}} {
   # adding a trait to an object
+  nx::trait::require $traitName
   nx::traitCheckObject [self] $traitName
   nx::traitAdd [self] -per-object $traitName $nameMap
 }
 
+#
+# The class "nx::Trait" provides the basic properties and methods needed for
+# the trait management.
+#
 nx::Class create nx::Trait {
-
+  :property {package}
   :property {requiredMethods:0..n,incremental ""}
   :property {requiredVariables:0..n,incremental ""}
 
   :public method "require trait" {traitName {nameMap ""}} {
     # adding a trait to a trait
+    nx::trait::require $traitName
     nx::trait::add [self] -per-object $traitName $nameMap
     set finalReqMethods {}
     foreach m [lsort -unique [concat ${:requiredMethods} [$traitName requiredMethods]]] {