Index: generic/gentclAPI.decls
===================================================================
diff -u -r901ceb8f58714e31d28ed3277923fc69c085d252 -r464811a4aaa475de10e834b0a009521446163fc0
--- generic/gentclAPI.decls	(.../gentclAPI.decls)	(revision 901ceb8f58714e31d28ed3277923fc69c085d252)
+++ generic/gentclAPI.decls	(.../gentclAPI.decls)	(revision 464811a4aaa475de10e834b0a009521446163fc0)
@@ -83,7 +83,7 @@
 }
 xotclCmd is XOTclIsCmd {
   {-argName "object" -required 1 -type tclobj}
-  {-argName "objectkind" -type "type|object|class|baseclass|metaclass|mixin"}
+  {-argName "objectkind" -type "type|object|class|baseclass|metaclass|hasmixin"}
   {-argName "value" -required 0 -type tclobj}
 }
 xotclCmd method XOTclMethodCmd {
Index: generic/predefined.h
===================================================================
diff -u -r901ceb8f58714e31d28ed3277923fc69c085d252 -r464811a4aaa475de10e834b0a009521446163fc0
--- generic/predefined.h	(.../predefined.h)	(revision 901ceb8f58714e31d28ed3277923fc69c085d252)
+++ generic/predefined.h	(.../predefined.h)	(revision 464811a4aaa475de10e834b0a009521446163fc0)
@@ -438,8 +438,8 @@
 "::xotcl::Attribute createFromParameterSyntax [self] {*}$arg}\n"
 "::xotcl::setinstvar [::xotcl::self]::slot __parameter $arglist}\n"
 "proc createBootstrapAttributeSlots {} {}\n"
-"::xotcl::Slot method type=mixin {name value arg} {\n"
-"if {![::xotcl::is $value mixin $arg]} {\n"
+"::xotcl::Slot method type=hasmixin {name value arg} {\n"
+"if {![::xotcl::is $value hasmixin $arg]} {\n"
 "error \"Value '$value' of $name has not mixin $arg\"}\n"
 "return $value}\n"
 "::xotcl::Slot method type=baseclass {name value} {\n"
Index: generic/predefined.xotcl
===================================================================
diff -u -r901ceb8f58714e31d28ed3277923fc69c085d252 -r464811a4aaa475de10e834b0a009521446163fc0
--- generic/predefined.xotcl	(.../predefined.xotcl)	(revision 901ceb8f58714e31d28ed3277923fc69c085d252)
+++ generic/predefined.xotcl	(.../predefined.xotcl)	(revision 464811a4aaa475de10e834b0a009521446163fc0)
@@ -853,13 +853,13 @@
   #   ::xotcl::is <obj> class
   #   ::xotcl::is <obj> baseclass
   #   ::xotcl::is <obj> metaclass
-  #   ::xotcl::is <obj> mixin <class>
+  #   ::xotcl::is <obj> hasmixin <class>
   #
   # Map these to type checkers. "object" and "class"
   # are already predefined, define the rest.
  
-  ::xotcl::Slot method type=mixin {name value arg} {
-    if {![::xotcl::is $value mixin $arg]} {
+  ::xotcl::Slot method type=hasmixin {name value arg} {
+    if {![::xotcl::is $value hasmixin $arg]} {
       error "Value '$value' of $name has not mixin $arg"
     }
     return $value
Index: generic/tclAPI.h
===================================================================
diff -u -r901ceb8f58714e31d28ed3277923fc69c085d252 -r464811a4aaa475de10e834b0a009521446163fc0
--- generic/tclAPI.h	(.../tclAPI.h)	(revision 901ceb8f58714e31d28ed3277923fc69c085d252)
+++ generic/tclAPI.h	(.../tclAPI.h)	(revision 464811a4aaa475de10e834b0a009521446163fc0)
@@ -68,13 +68,13 @@
 static int convertToObjectkind(Tcl_Interp *interp, Tcl_Obj *objPtr, XOTclParam CONST *pPtr, 
 			    ClientData *clientData, Tcl_Obj **outObjPtr) {
   int index, result;
-  static CONST char *opts[] = {"type", "object", "class", "baseclass", "metaclass", "mixin", NULL};
+  static CONST char *opts[] = {"type", "object", "class", "baseclass", "metaclass", "hasmixin", NULL};
   result = Tcl_GetIndexFromObj(interp, objPtr, opts, "objectkind", 0, &index);
   *clientData = (ClientData) INT2PTR(index + 1);
   *outObjPtr = objPtr;
   return result;
 }
-enum ObjectkindIdx {ObjectkindNULL, ObjectkindTypeIdx, ObjectkindObjectIdx, ObjectkindClassIdx, ObjectkindBaseclassIdx, ObjectkindMetaclassIdx, ObjectkindMixinIdx};
+enum ObjectkindIdx {ObjectkindNULL, ObjectkindTypeIdx, ObjectkindObjectIdx, ObjectkindClassIdx, ObjectkindBaseclassIdx, ObjectkindMetaclassIdx, ObjectkindHasmixinIdx};
   
 static int convertToMethodproperty(Tcl_Interp *interp, Tcl_Obj *objPtr, XOTclParam CONST *pPtr, 
 			    ClientData *clientData, Tcl_Obj **outObjPtr) {
Index: generic/xotcl.c
===================================================================
diff -u -r901ceb8f58714e31d28ed3277923fc69c085d252 -r464811a4aaa475de10e834b0a009521446163fc0
--- generic/xotcl.c	(.../xotcl.c)	(revision 901ceb8f58714e31d28ed3277923fc69c085d252)
+++ generic/xotcl.c	(.../xotcl.c)	(revision 464811a4aaa475de10e834b0a009521446163fc0)
@@ -11341,7 +11341,7 @@
 /*
 xotclCmd is XOTclIsCmd {
   {-argName "object" -required 1 -type tclobj}
-  {-argName "objectkind" -type "type|object|class|baseclass|metaclass|mixin"}
+  {-argName "objectkind" -type "type|object|class|baseclass|metaclass|hasmixin"}
   {-argName "value" -required 0 -type tclobj}
 }
 */
@@ -11382,8 +11382,8 @@
       && IsBaseClass((XOTclClass*)object);
     break;
 
-  case ObjectkindMixinIdx:
-    if (value == NULL) return XOTclObjErrArgCnt(interp, NULL, NULL, "<object> mixin <class>");
+  case ObjectkindHasmixinIdx:
+    if (value == NULL) return XOTclObjErrArgCnt(interp, NULL, NULL, "<object> hasmixin <class>");
     success = (GetObjectFromObj(interp, obj, &object) == TCL_OK)
       && (GetClassFromObj(interp, value, &cl, 0) == TCL_OK)
       && hasMixin(interp, object, cl);
Index: library/lib/xotcl1.xotcl
===================================================================
diff -u -r901ceb8f58714e31d28ed3277923fc69c085d252 -r464811a4aaa475de10e834b0a009521446163fc0
--- library/lib/xotcl1.xotcl	(.../xotcl1.xotcl)	(revision 901ceb8f58714e31d28ed3277923fc69c085d252)
+++ library/lib/xotcl1.xotcl	(.../xotcl1.xotcl)	(revision 464811a4aaa475de10e834b0a009521446163fc0)
@@ -383,7 +383,7 @@
   Object instproc isobject    {{object:substdefault "[self]"}} {::xotcl::is $object object}
   Object instproc isclass     {{class:substdefault  "[self]"}} {::xotcl::is $class class}
   Object instproc ismetaclass {{class:substdefault  "[self]"}} {::xotcl::is $class metaclass}
-  Object instproc ismixin     {class}  {::xotcl::is [self] mixin $class}
+  Object instproc ismixin     {class}  {::xotcl::is [self] hasmixin $class}
   Object instproc istype      {class}  {::xotcl::is [self] type $class}
 
   ::xotcl::alias Object contains ::xotcl::classes::xotcl2::Object::contains
@@ -478,7 +478,7 @@
 
   # support for XOTcl 1.* specific convenience routines
   Object instproc hasclass cl {
-    if {[::xotcl::is [self] mixin $cl]} {return 1}
+    if {[::xotcl::is [self] hasmixin $cl]} {return 1}
     ::xotcl::is [self] type $cl
   }
   Object instproc filtersearch {filter} {
Index: tests/parameters.xotcl
===================================================================
diff -u -r901ceb8f58714e31d28ed3277923fc69c085d252 -r464811a4aaa475de10e834b0a009521446163fc0
--- tests/parameters.xotcl	(.../parameters.xotcl)	(revision 901ceb8f58714e31d28ed3277923fc69c085d252)
+++ tests/parameters.xotcl	(.../parameters.xotcl)	(revision 464811a4aaa475de10e834b0a009521446163fc0)
@@ -506,15 +506,15 @@
 C create c1 -mixin M
 Object create o
 
-D method foo-base   {x:baseclass} {return $x}
-D method foo-class  {x:class} {return $x}
-D method foo-object {x:object} {return $x}
-D method foo-meta   {x:metaclass} {return $x}
-D method foo-mixin  {x:mixin,arg=::M} {return $x}
-D method foo-type   {x:object,type=::C} {return $x}
+D method foo-base     {x:baseclass} {return $x}
+D method foo-class    {x:class} {return $x}
+D method foo-object   {x:object} {return $x}
+D method foo-meta     {x:metaclass} {return $x}
+D method foo-hasmixin {x:hasmixin,arg=::M} {return $x}
+D method foo-type     {x:object,type=::C} {return $x}
 
 ? {D info method parameter foo-base} "x:baseclass"
-? {D info method parameter foo-mixin} "x:mixin,arg=::M"
+? {D info method parameter foo-hasmixin} "x:hasmixin,arg=::M"
 ? {D info method parameter foo-type} "x:object,type=::C"
 
 ? {d1 foo-base ::xotcl2::Object} "::xotcl2::Object"
@@ -535,8 +535,8 @@
     "Value '::xotcl2::Object' of x is not a metaclass" \
     "not a base class"
 
-? {d1 foo-mixin c1} "c1"
-? {d1 foo-mixin o} \
+? {d1 foo-hasmixin c1} "c1"
+? {d1 foo-hasmixin o} \
     "Value 'o' of x has not mixin ::M" \
     "does not have mixin M"
 
@@ -622,7 +622,7 @@
   d:object,type=::C
   d1:object,type=C
   m:metaclass
-  mix:mixin,arg=M
+  mix:hasmixin,arg=M
   b:baseclass
   u:upper
   us:upper,multivalued
@@ -642,7 +642,7 @@
 ? {parameterFromSlot ParamTest c1} "c1:class,type=::MC,slot=::ParamTest::slot::c1"
 ? {parameterFromSlot ParamTest d} "d:object,type=::C,slot=::ParamTest::slot::d"
 ? {parameterFromSlot ParamTest d1} "d1:object,type=::C,slot=::ParamTest::slot::d1"
-? {parameterFromSlot ParamTest mix} "mix:mixin,arg=M,slot=::ParamTest::slot::mix"
+? {parameterFromSlot ParamTest mix} "mix:hasmixin,arg=M,slot=::ParamTest::slot::mix"
 ? {parameterFromSlot ParamTest x} "x:object,multivalued,slot=::ParamTest::slot::x o"
 ? {parameterFromSlot ParamTest u} "u:upper,slot=::ParamTest::slot::u"
 ? {parameterFromSlot ParamTest us} "us:upper,multivalued,slot=::ParamTest::slot::us"
@@ -682,9 +682,8 @@
 ? {ParamTest create p -us {A B}} ::p
 ? {p us add C end} "A B C"
 
-# TODO: naming "type" and "mixin" not perfect.
+# TODO: naming "type" not perfect.
 #       maybe "type" => "hastype"
-#       maybe "mixin" => "hasmixin"
 #       => effects as well ::xotcl::is
 #
 # TODO (optimization): optimizer can improve parameter checking: