Index: generic/predefined.xotcl
===================================================================
diff -u -r1e72a93dd117734d0ab49c7ea7aa87f69f9a00b5 -r05f4b42f7615ea410b7ac33093f5b8382ce7e8c5
--- generic/predefined.xotcl	(.../predefined.xotcl)	(revision 1e72a93dd117734d0ab49c7ea7aa87f69f9a00b5)
+++ generic/predefined.xotcl	(.../predefined.xotcl)	(revision 05f4b42f7615ea410b7ac33093f5b8382ce7e8c5)
@@ -413,14 +413,14 @@
   }
   
   #
-  # create class and object for parameter slots
-  ::xotcl::MetaSlot create ::xotcl::ParameterSlot
-  foreach cmd [info command ::xotcl::cmd::ParameterSlot::*] {
-    ::xotcl::alias ::xotcl::ParameterSlot [namespace tail $cmd] $cmd
+  # create class and object for method parameter slots
+  ::xotcl::MetaSlot create ::xotcl::MethodParameterSlot
+  foreach cmd [info command ::xotcl::cmd::MethodParameterSlot::*] {
+    ::xotcl::alias ::xotcl::MethodParameterSlot [namespace tail $cmd] $cmd
   }
   
   # create an object for dispatching
-  ::xotcl::ParameterSlot create ::xotcl::parameterSlot
+  ::xotcl::MethodParameterSlot create ::xotcl::methodParameterSlot
   
   
   # use low level interface for defining slot values. Normally, this is
@@ -542,25 +542,24 @@
   }
   
   ############################################
-  #  InfoSlot
+  #  RelationSlot
   ############################################
-  ::xotcl::MetaSlot create ::xotcl::InfoSlot
-  createBootstrapAttributeSlots ::xotcl::InfoSlot {
+  ::xotcl::MetaSlot create ::xotcl::RelationSlot
+  createBootstrapAttributeSlots ::xotcl::RelationSlot {
     {multivalued true}
+    {type relation}
     {elementtype ::xotcl2::Class}
   }
-  ::xotcl::relation ::xotcl::InfoSlot superclass ::xotcl::Slot
-  ::xotcl::InfoSlot public method get {obj prop} {
-    $obj info $prop
-  }
-  ::xotcl::InfoSlot public method add {obj prop value {pos 0}} {
-    if {![set :multivalued]} {
-      error "Property $prop of ${:domain}->$obj ist not multivalued"
+  ::xotcl::relation ::xotcl::RelationSlot superclass ::xotcl::Slot
+  ::xotcl::alias ::xotcl::RelationSlot assign ::xotcl::relation
+
+  ::xotcl::RelationSlot protected method init {} {
+    if {${:type} ne "relation"} {
+      error "RelationSlot requires type == \"relation\""
     }
-    #puts stderr "adding infoslot: $obj $prop [linsert [$obj info $prop] $pos $value]"
-    $obj $prop [linsert [$obj info $prop] $pos $value]
+    next
   }
-  ::xotcl::InfoSlot protected method delete_value {obj prop old value} {
+  ::xotcl::RelationSlot protected method delete_value {obj prop old value} {
     if {[string first * $value] > -1 || [string first \[ $value] > -1} {
       # string contains meta characters
       if {${:elementtype} ne "" && ![string match ::* $value]} {
@@ -587,69 +586,55 @@
     }
   }
   
-  ::xotcl::InfoSlot public method delete {-nocomplain:switch obj prop value} {
-    #puts stderr infoslot-delete-[self args]
+  ::xotcl::RelationSlot public method delete {-nocomplain:switch obj prop value} {
+    #puts stderr RelationSlot-delete-[self args]
     $obj $prop [:delete_value $obj $prop [$obj info $prop] $value]
   }
   
-  ############################################
-  # InterceptorSlot
-  ############################################
-  ::xotcl::MetaSlot alloc ::xotcl::InterceptorSlot
-  
-  ::xotcl::relation ::xotcl::InterceptorSlot superclass ::xotcl::InfoSlot
-  ::xotcl::alias ::xotcl::InterceptorSlot set ::xotcl::relation ;# for backwards compatibility
-  ::xotcl::alias ::xotcl::InterceptorSlot assign ::xotcl::relation
-  
-  ::xotcl::InterceptorSlot public method get {obj prop} {
+  ::xotcl::RelationSlot public method get {obj prop} {
     ::xotcl::relation $obj $prop
   }
-  ::xotcl::InterceptorSlot public method add {obj prop value {pos 0}} {
+  ::xotcl::RelationSlot public method add {obj prop value {pos 0}} {
     if {![set :multivalued]} {
       error "Property $prop of ${:domain}->$obj ist not multivalued"
     }
     set oldSetting [::xotcl::relation $obj $prop]
     # use uplevel to avoid namespace surprises
     uplevel [list ::xotcl::relation $obj $prop [linsert $oldSetting $pos $value]]
   }
-  ::xotcl::InterceptorSlot public method delete {-nocomplain:switch obj prop value} {
+  ::xotcl::RelationSlot public method delete {-nocomplain:switch obj prop value} {
     uplevel [list ::xotcl::relation $obj $prop [:delete_value $obj $prop [::xotcl::relation $obj $prop] $value]]
   }
   
+  
   ############################################
   # system slots
   ############################################
   proc ::xotcl::register_system_slots {os} {
     ${os}::Object alloc ${os}::Class::slot
     ${os}::Object alloc ${os}::Object::slot
     
-    ::xotcl::InfoSlot create ${os}::Class::slot::superclass -type relation
+    ::xotcl::RelationSlot create ${os}::Class::slot::superclass
     ::xotcl::alias           ${os}::Class::slot::superclass assign ::xotcl::relation
-    ::xotcl::InfoSlot create ${os}::Object::slot::class -type relation
+    ::xotcl::RelationSlot create ${os}::Object::slot::class -multivalued false
     ::xotcl::alias           ${os}::Object::slot::class assign ::xotcl::relation
     
-    ::xotcl::InterceptorSlot create ${os}::Object::slot::mixin \
-        -type relation -methodname object-mixin
+    ::xotcl::RelationSlot create ${os}::Object::slot::mixin \
+        -methodname object-mixin
     
-    ::xotcl::InterceptorSlot create ${os}::Object::slot::filter \
-        -elementtype "" -type relation
+    ::xotcl::RelationSlot create ${os}::Object::slot::filter \
+        -elementtype ""
     
-    ::xotcl::InterceptorSlot create ${os}::Class::slot::mixin \
-        -type relation -methodname class-mixin
-    ::xotcl::InterceptorSlot create ${os}::Class::slot::filter \
-        -type relation -methodname filter-mixin
+    ::xotcl::RelationSlot create ${os}::Class::slot::mixin \
+        -methodname class-mixin
+    ::xotcl::RelationSlot create ${os}::Class::slot::filter \
+        -methodname filter-mixin
     
     # create tho conveniance slots to allow configuration of 
     # object-slots for classes via object-mixin
-    ::xotcl::InterceptorSlot create ${os}::Class::slot::object-mixin \
-        -type relation
-    ::xotcl::InterceptorSlot create ${os}::Class::slot::object-filter \
-        -elementtype "" -type relation
-    
-    # We could define a mixin on class, the calls always class-mixin.
-    # therfore, 
-    #::xotcl::InterceptorSlot create ${os}::Class::slot::mixin \
-        #    -type relation -methodname class-mixin
+    ::xotcl::RelationSlot create ${os}::Class::slot::object-mixin 
+    ::xotcl::RelationSlot create ${os}::Class::slot::object-filter \
+        -elementtype ""
   }
   ::xotcl::register_system_slots ::xotcl2