Index: generic/nsf.c
===================================================================
diff -u -r9124d823b4eb4a8b5969b9fa1b6eab7252ba83b4 -r364a9eda329acd7d20173a4165d71394d3061aae
--- generic/nsf.c	(.../nsf.c)	(revision 9124d823b4eb4a8b5969b9fa1b6eab7252ba83b4)
+++ generic/nsf.c	(.../nsf.c)	(revision 364a9eda329acd7d20173a4165d71394d3061aae)
@@ -16412,11 +16412,12 @@
   *outObjPtr = objPtr;
 
   /*
-   * If argument checking is turned off, and we do not have an converter, do
-   * nothing.
+   * Omit argument checking, provided that ...
+   * ... argument checking is turned off *and* no converter is specified, or
+   * ... the ruling parameter option is 'initcmd'
    */
-  if (unlikely(doCheck == 0) && (pPtr->flags & (NSF_ARG_IS_CONVERTER|NSF_ARG_INITCMD)) == 0) {
-    /*fprintf(stderr, "*** omit  argument check for arg %s flags %.6x\n", pPtr->name, pPtr->flags);*/
+  if ((unlikely(doCheck == 0) && (pPtr->flags & (NSF_ARG_IS_CONVERTER)) == 0) || (pPtr->flags & (NSF_ARG_INITCMD))) {
+    /* fprintf(stderr, "*** omit  argument check for arg %s flags %.6x\n", pPtr->name, pPtr->flags); */
     *clientData = ObjStr(objPtr);
     return TCL_OK;
   }
Index: library/nx/nx.tcl
===================================================================
diff -u -r5ce68a42506fcc981cea2431afa1b09b476e667a -r364a9eda329acd7d20173a4165d71394d3061aae
--- library/nx/nx.tcl	(.../nx.tcl)	(revision 5ce68a42506fcc981cea2431afa1b09b476e667a)
+++ library/nx/nx.tcl	(.../nx.tcl)	(revision 364a9eda329acd7d20173a4165d71394d3061aae)
@@ -1243,8 +1243,11 @@
       set options [:getParameterOptions -withMultiplicity true -forObjectParameter true]
       if {[info exists :initcmd]} {
 	lappend options initcmd
-	set :parameterSpec [list [:namedParameterSpec $prefix ${:name} $options] ${:initcmd}]
-	
+	if {[info exists :default]} {
+	  append initcmd "::nsf::var::set \[::nsf::self\] ${:name} ${:default};\n"
+	}
+	append initcmd ${:initcmd}
+	set :parameterSpec [list [:namedParameterSpec $prefix ${:name} $options] $initcmd]
       } elseif {[info exists :default]} {
 	# deactivated for now: || [string first {$} ${:default}] > -1
 	if {[string match {*\[*\]*} ${:default}]} {
@@ -1540,7 +1543,6 @@
     {accessor true}
     {type}
     {settername}
-
     valuecmd
     defaultcmd
     valuechangedcmd
Index: library/xotcl/library/xotcl2.tcl
===================================================================
diff -u -ra57782b043b4b1b9b81b0c7534365d36b01457ac -r364a9eda329acd7d20173a4165d71394d3061aae
--- library/xotcl/library/xotcl2.tcl	(.../xotcl2.tcl)	(revision a57782b043b4b1b9b81b0c7534365d36b01457ac)
+++ library/xotcl/library/xotcl2.tcl	(.../xotcl2.tcl)	(revision 364a9eda329acd7d20173a4165d71394d3061aae)
@@ -919,15 +919,38 @@
       if {[info exists :parameter]} {my ::nsf::classes::xotcl::Class::parameter ${:parameter}}
       next
     }
-    # provide minimal compatibility
+
     :public forward instproc %self public method
     :public forward proc %self public class method
+
     #
     # As NX/XOTcl hybrids, all slot kinds would not inherit the
     # unknown behaviour of ::xotcl::Class. Therefore, we provide it
     # explicitly to slots for backward compatibility ...
     #
     :public alias unknown ::nsf::classes::xotcl::Class::unknown
+    :public method objectparameter {} {
+      set parameterdefinitions [list]
+      set slots [nsf::directdispatch [self] \
+		     ::nsf::methods::class::info::slotobjects \
+		     -closure -type ::nx::Slot]
+      foreach slot $slots {
+	#
+	# Skip any positional object parameters (i.e., __initcmd)
+	# which are not backward compatible with the XOTcl slots
+	# interface ...
+	#
+	if {[$slot eval {
+	  expr {[info exists :positional] && ${:positional}}
+	}]} continue;
+	lappend parameterdefinitions [$slot getParameterSpec]
+      }
+      #
+      # Add the XOTcl-specific handling of residual varargs
+      #
+      lappend parameterdefinitions args:alias,method=residualargs,args
+      return $parameterdefinitions
+    }
   }
 
   #
@@ -944,9 +967,13 @@
 	return [$object eval [list :isMultivalued]]
       }
     }
+    # provide minimal compatibility
+    :public forward proc %self public method
     :public method exists {var} {::nsf::var::exists [self] $var}
     :public method istype {class} [::nx::Object info method body ::nsf::classes::xotcl::Object::istype]
     :public alias set -frame object ::set
+    :public alias residualargs ::nsf::methods::object::residualargs
+    :public alias instvar  ::nsf::methods::object::instvar
   }
 
   #
Index: library/xotcl/tests/slottest.xotcl
===================================================================
diff -u -r65e384fc5b5fa044c63075f03756da88d316249f -r364a9eda329acd7d20173a4165d71394d3061aae
--- library/xotcl/tests/slottest.xotcl	(.../slottest.xotcl)	(revision 65e384fc5b5fa044c63075f03756da88d316249f)
+++ library/xotcl/tests/slottest.xotcl	(.../slottest.xotcl)	(revision 364a9eda329acd7d20173a4165d71394d3061aae)
@@ -452,16 +452,14 @@
 ? {p2 salary} 1009
 
 Person slots {
-  Attribute create sex -type "sex" -convert true {
-    :public method type=sex {name value} {
+  Attribute create sex -type "sex" -convert true -proc type=sex {name value} {
       #puts stderr "[self] slot specific converter"
       switch -glob $value {
         m* {return m}
         f* {return f}
         default {error "expected sex but got $value"}
       }
     }
-  }
 }
 Person p3 -sex male
 ? {p3 sex} m
@@ -522,13 +520,11 @@
 nx::Test case assign-via-slots
 
 Class create A -slots {
-  Attribute create foo -default 1 {
-    :public method assign {domain var value} {
-      if {$value < 0 || $value > 99} {
-        error "$value is not in the range of 0 .. 99"
-      }
-      $domain set $var $value
+  Attribute create foo -default 1 -proc  assign {domain var value} {
+    if {$value < 0 || $value > 99} {
+      error "$value is not in the range of 0 .. 99"
     }
+    $domain set $var $value
   }
 }
 
@@ -618,6 +614,25 @@
 ? {catch {p2 name add BOOM!}} 1
 ? {p2 name} "John Doe"
 
+#
+# 3) -proc inline statements upon Attribute creation
+#    (as found in the tutorial)
+#
+
+Class create AA -slots {
+    Attribute foo -default 1 -proc assign {domain var value} {
+	if {$value < 0 || $value > 99} {
+	    error "$value is not in the range of 0 .. 99"
+	}  
+	$domain set $var $value
+    }
+}
+
+AA create aa1
+? {aa1 foo 10} 10
+? {aa1 foo} 10
+? {catch {aa1 foo -1}} 1
+
 exit
 
   #puts [Person array get __defaults]
Index: tests/parameters.test
===================================================================
diff -u -r770232a210b63fdafc5e5e4a2caf45fa5097c6fe -r364a9eda329acd7d20173a4165d71394d3061aae
--- tests/parameters.test	(.../parameters.test)	(revision 770232a210b63fdafc5e5e4a2caf45fa5097c6fe)
+++ tests/parameters.test	(.../parameters.test)	(revision 364a9eda329acd7d20173a4165d71394d3061aae)
@@ -1337,6 +1337,141 @@
   ? {d1 c 5} 999
 }
 
+nx::Test case slot-trace-interaction {
+  #
+  # 1) Verify the controlled interactions between trace types
+  #
+  # per-object:
+  #
+
+  package req nx::serializer
+
+  Object create o 
+
+  ? {o eval {info exists :a}} 0
+  ? {o property {a 0} {
+    set :defaultcmd {set _ 4}
+  }} "defaultcmd can't be used together with default value"
+
+  ? {o eval {info exists :a}} 0
+
+  ? {o eval {info exists :b}} 0
+  ? {o property {b 0} {
+    set :valuecmd {set _ 44}
+  }} "valuecmd can't be used together with default value"
+  ? {o eval {info exists :b}} 0
+
+  ? {o eval {info exists :c}} 0
+  ? {o property c {
+    set :defaultcmd {set _ 4}
+    set :valuecmd {set _ 44}
+  }} "valuecmd can't be used together with defaultcmd"
+  ? {o eval {info exists :c}} 0
+  
+  #
+  # valuechangedcmd + default value are allowed
+  #
+
+  ? {o eval {info exists :a}} 0
+  o property {a 0} {
+    set :valuechangedcmd {::nsf::var::set $obj $var [expr [list [::nsf::var::set $obj $var] + 1]]}
+  }
+  ? {o eval {info exists :a}} 1
+
+  ? {o a} 1
+  ? {o a 1} 2
+  ? {o a} 2
+  ? {o a 2} 3
+
+  # per-class:
+
+  Class create Klass
+  
+  ? {Klass property {a 0} {
+    set :defaultcmd {set _ 4}
+  }} "defaultcmd can't be used together with default value"
+
+  ? {Klass property {b 0} {
+    set :valuecmd {set _ 44}
+  }} "valuecmd can't be used together with default value"
+
+  ? {Klass property c {
+    set :defaultcmd {set _ 4}
+    set :valuecmd {set _ 44}
+  }} "valuecmd can't be used together with defaultcmd"
+
+  Klass property {a 0} {
+    set :valuechangedcmd {::nsf::var::set $obj $var [expr [list [::nsf::var::set $obj $var] + 1]]}
+  }
+
+  #
+  # TODO: Right now, the per-object traces *do* fire upon setting the
+  # default value; the per-class traces won't ... this should be
+  # symmetric, either way ...
+  #
+  
+  Klass create k
+  ? {k eval {info exists :a}} 1
+  ? {k a} 0; # should be 1, reflecting the corresponding per-object case above
+  ? {k a 1} 2
+  ? {k a} 2
+  ? {k a 2} 3
+
+  #
+  # 2) Have initcmd scripts escaped from C-level argument checking (in
+  # the per-class check)
+  #
+  # a) against scalar checkers (as a simplistic case)
+
+  Klass property b:boolean {
+    set :valuechangedcmd {set _ tr1e}
+  }
+ 
+  ? {catch {Klass create kk}} 0
+  
+  #
+  # b) Structured trace scripts, containing lists. Check for
+  # brace balancedness ...
+  # 
+  # Background: Script blocks passed as initcmds should not be
+  # subjected to *any* argument checking. This was not guaranteed,
+  # previously. As a result, for example, upon multivalued argument
+  # checking (e.g., 0..n) the argument (i.e., the initcmd block) was
+  # tentatively expanded into a Tcl list. This failed for initcmd
+  # scripts which do not qualify as valid list structures (a condition
+  # not to be enforced).
+  #
+  # Below, we introduce three tests capturing the unwanted
+  # interaction, now fixed. Note: This issue only affects
+  # class-wide initcmds, as in the per-object case, the initcmds are
+  # evaluated right away and not fiddled through the parameter handling
+  # infrastructure.
+  ::nx::Class create CC {
+    :property a:0..n {
+      set :defaultcmd {
+  	if 1 {
+  	  set _ 4
+  	}
+      } 
+    }
+    
+    :property b:0..n {set :valuecmd {if 1 {set _ 44}} }
+    :property c:0..n {
+      set :valuechangedcmd {
+	if 1 {
+	  ::nsf::var::set $obj $var 999
+	}
+      }
+    }
+    :create ::cc
+  }
+
+  ? {cc a} 4
+  ? {cc b} 44
+  ? {cc c 5} 999
+  
+}
+
 ::nsf::configure checkarguments off
 nx::Test case check-arguments-nocheck {