diff --git a/lib/interpreter/interpreter.rb b/lib/interpreter/interpreter.rb
index b476fe42..a6ea9ae6 100644
--- a/lib/interpreter/interpreter.rb
+++ b/lib/interpreter/interpreter.rb
@@ -205,7 +205,7 @@ module Interpreter
       else
         raise "unimplemented  '#{@instruction.operator}' #{@instruction}"
       end
-      puts "#{@instruction} == #{result}   (#{left}|#{right})"
+      #puts "#{@instruction} == #{result}   (#{left}|#{right})"
       right = set_register(@instruction.left , result)
       true
     end
diff --git a/lib/parfait/frame.rb b/lib/parfait/frame.rb
index ef501cc6..ed522dac 100644
--- a/lib/parfait/frame.rb
+++ b/lib/parfait/frame.rb
@@ -20,7 +20,7 @@ module Parfait
     attribute :next_frame
 
     def self.offset
-      1 + Space.object_space.get_class_by_name(:Frame).object_layout.object_instance_length
+      1 + Space.object_space.get_class_by_name(:Frame).object_layout.instance_length
     end
 
   end
diff --git a/lib/parfait/message.rb b/lib/parfait/message.rb
index d33067a7..ee4d547b 100644
--- a/lib/parfait/message.rb
+++ b/lib/parfait/message.rb
@@ -30,7 +30,7 @@ module Parfait
     end
 
     def self.offset
-      1 + Space.object_space.get_class_by_name(:Message).object_layout.object_instance_length
+      1 + Space.object_space.get_class_by_name(:Message).object_layout.instance_length
     end
   end
 end
diff --git a/lib/parfait/object.rb b/lib/parfait/object.rb
index 6001953d..b42f4e2f 100644
--- a/lib/parfait/object.rb
+++ b/lib/parfait/object.rb
@@ -73,7 +73,7 @@ module Parfait
     end
 
     def get_instance_variables
-      get_layout().object_instance_names
+      get_layout().instance_names
     end
 
     def get_instance_variable name
diff --git a/lib/register/collector.rb b/lib/register/collector.rb
index a52cd72b..88bfafa1 100644
--- a/lib/register/collector.rb
+++ b/lib/register/collector.rb
@@ -23,7 +23,7 @@ module Register
       layout = object.get_layout
       keep(layout  , depth + 1)
       return if object.is_a? Symbol
-      layout.object_instance_names.each do |name|
+      layout.instance_names.each do |name|
         #puts "Keep #{name} for #{object.class}"
         inst = object.get_instance_variable name
         keep(inst , depth + 1)
diff --git a/test/parfait/test_attributes.rb b/test/parfait/test_attributes.rb
index cd24ce20..764f6461 100644
--- a/test/parfait/test_attributes.rb
+++ b/test/parfait/test_attributes.rb
@@ -12,11 +12,11 @@ class TestAttributes < MiniTest::Test
   end
   def test_message_layout_first
     @layout.object_class = :next_message
-    assert_equal :layout , @layout.object_instance_names.first
+    assert_equal :layout , @layout.instance_names.first
     assert_equal :next_message , @layout.object_class
   end
   def test_message_name_nil
-    last = @layout.object_instance_names.last
+    last = @layout.instance_names.last
     assert_equal :name , last
     assert_equal nil , @mess.name
   end
diff --git a/test/parfait/test_layout.rb b/test/parfait/test_layout.rb
index 6df8a575..7726db34 100644
--- a/test/parfait/test_layout.rb
+++ b/test/parfait/test_layout.rb
@@ -24,10 +24,6 @@ class TestLayout < MiniTest::Test
     assert_equal @mess.get_layout , @mess.internal_object_get(0) , "mess"
   end
 
-  def test_forbidden_index_of
-    assert_raises(RuntimeError) { @mess.get_layout.index_of(:name)}
-  end
-
   def test_inspect
     assert @mess.get_layout.inspect.start_with?("Layout")
   end
@@ -37,12 +33,12 @@ class TestLayout < MiniTest::Test
   end
 
   def test_length
-    assert_equal 8 , @mess.get_layout.object_instance_length , @mess.get_layout.inspect
+    assert_equal 8 , @mess.get_layout.instance_length , @mess.get_layout.inspect
   end
 
   def test_no_index_below_1
     layout = @mess.get_layout
-    names = layout.object_instance_names
+    names = layout.instance_names
     assert_equal 8 , names.get_length , names.inspect
     names.each do |n|
       assert layout.variable_index(n) >= 1
@@ -54,7 +50,7 @@ class TestLayout < MiniTest::Test
     assert_equal Parfait::Class , oc.class
     layout = oc.object_layout
     assert_equal Parfait::Layout , layout.class
-    assert_equal 1 , layout.object_instance_names.get_length
+    assert_equal 1 , layout.instance_names.get_length
     assert_equal layout.first , :layout
   end
 
diff --git a/test/parfait/test_object.rb b/test/parfait/test_object.rb
index cf14be76..13293a41 100644
--- a/test/parfait/test_object.rb
+++ b/test/parfait/test_object.rb
@@ -7,7 +7,7 @@ class TestObject < MiniTest::Test
   end
 
   def test_object_create
-    assert_equal 1 ,  @object.get_layout.object_instance_length
+    assert_equal 1 ,  @object.get_layout.instance_length
   end
 
   def test_empty_object_doesnt_return