diff --git a/include/xo/expression2/DLambdaExpr.hpp b/include/xo/expression2/DLambdaExpr.hpp
index 2a0cc2c3..b21a37ce 100644
--- a/include/xo/expression2/DLambdaExpr.hpp
+++ b/include/xo/expression2/DLambdaExpr.hpp
@@ -20,6 +20,7 @@ namespace xo {
          **/
         class DLambdaExpr {
         public:
+            using ACollector = xo::mm::ACollector;
             using AAllocator = xo::mm::AAllocator;
             using TypeDescr = xo::reflect::TypeDescr;
             using ppindentinfo = xo::print::ppindentinfo;
@@ -78,6 +79,14 @@ namespace xo {
             TypeDescr valuetype() const noexcept;
             void assign_valuetype(TypeDescr td) noexcept;
 
+            ///@}
+            /** @defgroup scm-lambdaexpr-gcobject-facet **/
+            ///@{
+
+            std::size_t shallow_size() const noexcept;
+            DLambdaExpr * shallow_copy(obj<AAllocator> mm) const noexcept;
+            std::size_t forward_children(obj<ACollector> gc) noexcept;
+
             ///@}
             /** @defgroup scm-lambdaexpr-printable-facet **/
             ///@{
@@ -95,7 +104,7 @@ namespace xo {
             /** name for this lambda (generated if necessary) **/
             const DUniqueString * name_ = nullptr;
 
-#ifdef NOT_YET
+#ifdef NOT_YET // when enabled, need to visit forward_children()
             /** e.g.
              *    i64(f64,string)
              *  for function of two arguments with types (f64, string) respectively,
diff --git a/include/xo/expression2/IfElseExpr.hpp b/include/xo/expression2/IfElseExpr.hpp
new file mode 100644
index 00000000..901062b2
--- /dev/null
+++ b/include/xo/expression2/IfElseExpr.hpp
@@ -0,0 +1,13 @@
+/** @file IfElseExpr.hpp
+ *
+ *  @author Roland Conybeare, Feb 2026
+ **/
+
+#pragma once
+
+#include "DIfElseExpr.hpp"
+#include "detail/IExpression_DIfElseExpr.hpp"
+#include "detail/IGCObject_DIfElseExpr.hpp"
+#include "detail/IPrintable_DIfElseExpr.hpp"
+
+/* end IfElseExpr.hpp */
diff --git a/include/xo/expression2/UniqueString.hpp b/include/xo/expression2/UniqueString.hpp
new file mode 100644
index 00000000..90cd1cd2
--- /dev/null
+++ b/include/xo/expression2/UniqueString.hpp
@@ -0,0 +1,12 @@
+/** @file UniqueString.hpp
+ *
+ *  @author Roland Conybeare, Feb 2026
+ **/
+
+#pragma once
+
+#include "DUniqueString.hpp"
+#include "detail/IGCObject_DUniqueString.hpp"
+#include "detail/IPrintable_DUniqueString.hpp"
+
+/* end UniqueString.hpp */
diff --git a/src/expression2/CMakeLists.txt b/src/expression2/CMakeLists.txt
index 45b5a06e..749910e4 100644
--- a/src/expression2/CMakeLists.txt
+++ b/src/expression2/CMakeLists.txt
@@ -10,15 +10,13 @@ set(SELF_SRCS
     DVariable.cpp
     DVarRef.cpp
     DDefineExpr.cpp
-    DLambdaExpr.cpp
     DApplyExpr.cpp
-    DIfElseExpr.cpp
-    DSequenceExpr.cpp
 
     TypeRef.cpp
     Binding.cpp
 
     IExpression_Any.cpp
+    ISymbolTable_Any.cpp
 
     IExpression_DConstant.cpp
     IGCObject_DConstant.cpp
@@ -39,25 +37,28 @@ set(SELF_SRCS
     IGCObject_DApplyExpr.cpp
     IPrintable_DApplyExpr.cpp
 
+    DLambdaExpr.cpp
     IExpression_DLambdaExpr.cpp
+    IGCObject_DLambdaExpr.cpp
     IPrintable_DLambdaExpr.cpp
 
+    DIfElseExpr.cpp
     IExpression_DIfElseExpr.cpp
     IGCObject_DIfElseExpr.cpp
     IPrintable_DIfElseExpr.cpp
 
+    DSequenceExpr.cpp
     IExpression_DSequenceExpr.cpp
     IGCObject_DSequenceExpr.cpp
     IPrintable_DSequenceExpr.cpp
 
     DLocalSymtab.cpp
-    DGlobalSymtab.cpp
-
-    ISymbolTable_Any.cpp
-
     ISymbolTable_DLocalSymtab.cpp
+    IGCObject_DLocalSymtab.cpp
     IPrintable_DLocalSymtab.cpp
 
+    DGlobalSymtab.cpp
+
     StringTable.cpp
 
     DUniqueString.cpp
diff --git a/src/expression2/DIfElseExpr.cpp b/src/expression2/DIfElseExpr.cpp
index 631be466..6a0b053c 100644
--- a/src/expression2/DIfElseExpr.cpp
+++ b/src/expression2/DIfElseExpr.cpp
@@ -80,32 +80,6 @@ namespace xo {
             typeref_.resolve(td);
         }
 
-        bool
-        DIfElseExpr::pretty(const ppindentinfo & ppii) const
-        {
-            auto test
-                = FacetRegistry::instance().try_variant<APrintable,
-                                                        AExpression>(test_);
-            auto when_true
-                = FacetRegistry::instance().try_variant<APrintable,
-                                                        AExpression>(when_true_);
-            auto when_false
-                = FacetRegistry::instance().try_variant<APrintable,
-                                                        AExpression>(when_false_);
-
-            bool test_present = test;
-            bool when_true_present = when_true;
-            bool when_false_present = when_false;
-
-            return ppii.pps()->pretty_struct
-                       (ppii,
-                        "DIfElseExpr",
-                        refrtag("typeref", typeref_),
-                        refrtag("test", test, test_present),
-                        refrtag("when_true", when_true, when_true_present),
-                        refrtag("when_false", when_false, when_false_present));
-        }
-
         // GCObject facet
 
         std::size_t
@@ -145,6 +119,34 @@ namespace xo {
             return shallow_size();
         }
 
+        // ----- printable facet -----
+
+        bool
+        DIfElseExpr::pretty(const ppindentinfo & ppii) const
+        {
+            auto test
+                = FacetRegistry::instance().try_variant<APrintable,
+                                                        AExpression>(test_);
+            auto when_true
+                = FacetRegistry::instance().try_variant<APrintable,
+                                                        AExpression>(when_true_);
+            auto when_false
+                = FacetRegistry::instance().try_variant<APrintable,
+                                                        AExpression>(when_false_);
+
+            bool test_present = test;
+            bool when_true_present = when_true;
+            bool when_false_present = when_false;
+
+            return ppii.pps()->pretty_struct
+                       (ppii,
+                        "DIfElseExpr",
+                        refrtag("typeref", typeref_),
+                        refrtag("test", test, test_present),
+                        refrtag("when_true", when_true, when_true_present),
+                        refrtag("when_false", when_false, when_false_present));
+        }
+
         // ----------------------------------------------------------------
 
 #ifdef NOPE
diff --git a/src/expression2/DLambdaExpr.cpp b/src/expression2/DLambdaExpr.cpp
index 080e49b5..56d55c03 100644
--- a/src/expression2/DLambdaExpr.cpp
+++ b/src/expression2/DLambdaExpr.cpp
@@ -3,16 +3,16 @@
  *  @author Roland Conybeare, Jan 2026
  **/
 
-#include "DLambdaExpr.hpp"
-#include "detail/IExpression_DLambdaExpr.hpp"
-#include "DLocalSymtab.hpp"
-#include "symtab/IPrintable_DLocalSymtab.hpp"
+#include "LambdaExpr.hpp"
+#include "LocalSymtab.hpp"
+#include "UniqueString.hpp"
 #include <xo/alloc2/Allocator.hpp>
 #include <xo/printable2/Printable.hpp>
 #include <xo/facet/FacetRegistry.hpp>
 #include <xo/reflectutil/typeseq.hpp>
 
 namespace xo {
+    using xo::mm::AGCObject;
     using xo::print::APrintable;
     using xo::facet::FacetRegistry;
     using xo::reflect::TypeDescr;
@@ -134,6 +134,49 @@ namespace xo {
             typeref_.resolve(td);
         }
 
+        std::size_t
+        DLambdaExpr::shallow_size() const noexcept {
+            return sizeof(DLambdaExpr);
+        }
+
+        DLambdaExpr *
+        DLambdaExpr::shallow_copy(obj<AAllocator> mm) const noexcept {
+            DLambdaExpr * copy = (DLambdaExpr *)mm.alloc_copy((std::byte *)this);
+
+            if (copy) {
+                *copy = *this;
+            }
+
+            return copy;
+        }
+
+        std::size_t
+        DLambdaExpr::forward_children(obj<ACollector> gc) noexcept {
+            {
+                auto iface = xo::facet::impl_for<AGCObject,DUniqueString>();
+                gc.forward_inplace(&iface, (void **)(&name_));
+            }
+
+            // type_name_str_
+
+            {
+                auto iface = xo::facet::impl_for<AGCObject,DLocalSymtab>();
+                gc.forward_inplace(&iface, (void **)(&local_symtab_));
+            }
+
+            {
+                auto iface = body_expr_.to_facet<AGCObject>().iface();
+                gc.forward_inplace(iface, (void **)(&body_expr_));
+            }
+
+            // xxx free_var_set
+            // xxx captured_var_set
+            // xxx layer_var_map
+            // xxx nested_lambda_map
+
+            return shallow_size();
+        }
+
         bool
         DLambdaExpr::pretty(const ppindentinfo & ppii) const
         {
diff --git a/src/expression2/DLocalSymtab.cpp b/src/expression2/DLocalSymtab.cpp
index 85631d34..cf9c8459 100644
--- a/src/expression2/DLocalSymtab.cpp
+++ b/src/expression2/DLocalSymtab.cpp
@@ -3,13 +3,14 @@
  *  @author Roland Conybeare, Jan 2026
  **/
 
-#include "DLocalSymtab.hpp"
+#include "LocalSymtab.hpp"
+#include "Variable.hpp"
 #include "DUniqueString.hpp"
-#include <xo/expression2/detail/IPrintable_DVariable.hpp>
 #include <xo/printable2/Printable.hpp>
 #include <xo/indentlog/scope.hpp>
 
 namespace xo {
+    using xo::mm::AGCObject;
     using xo::print::APrintable;
     using xo::facet::typeseq;
     using xo::print::ppstate;
@@ -77,6 +78,50 @@ namespace xo {
             return Binding();
         }
 
+        // ----- gcobject facet -----
+
+        std::size_t
+        DLocalSymtab::shallow_size() const noexcept
+        {
+            return (sizeof(DLocalSymtab) + (capacity_ * sizeof(Slot)));
+        }
+
+        DLocalSymtab *
+        DLocalSymtab::shallow_copy(obj<AAllocator> mm) const noexcept
+        {
+            DLocalSymtab * copy = (DLocalSymtab *)mm.alloc_copy((std::byte *)this);
+
+            if (copy) {
+                *copy = *this;
+
+                ::memcpy((void*)&(copy->slots_[0]),
+                         (void*)&(slots_[0]),
+                         capacity_ * sizeof(Slot));
+            }
+
+            return copy;
+        }
+
+        std::size_t
+        DLocalSymtab::forward_children(obj<ACollector> gc) noexcept
+        {
+            {
+                auto iface
+                    = xo::facet::impl_for<AGCObject,DLocalSymtab>();
+                gc.forward_inplace(&iface, (void **)(&parent_));
+            }
+
+            auto iface
+                = xo::facet::impl_for<AGCObject,DVariable>();
+            for (size_type i = 0; i < size_; ++i) {
+                gc.forward_inplace(&iface, (void **)(&(slots_[i].var_)));
+            }
+
+            return shallow_size();
+        }
+
+        // ----- printable facet -----
+
         bool
         DLocalSymtab::pretty(const ppindentinfo & ppii) const
         {
diff --git a/src/expression2/expression2_register_facets.cpp b/src/expression2/expression2_register_facets.cpp
index 67944a08..16bfac2a 100644
--- a/src/expression2/expression2_register_facets.cpp
+++ b/src/expression2/expression2_register_facets.cpp
@@ -17,28 +17,16 @@
 #include <xo/expression2/detail/IPrintable_DVariable.hpp>
 
 #include <xo/expression2/VarRef.hpp>
-
-#include <xo/expression2/detail/IExpression_DConstant.hpp>
-#include <xo/expression2/detail/IGCObject_DConstant.hpp>
-#include <xo/expression2/detail/IPrintable_DConstant.hpp>
-
+#include <xo/expression2/Constant.hpp>
 #include <xo/expression2/ApplyExpr.hpp>
-
-#include <xo/expression2/detail/IExpression_DLambdaExpr.hpp>
-//#include <xo/expression2/detail/IGCObject_DLambdaExpr.hpp>
-#include <xo/expression2/detail/IPrintable_DLambdaExpr.hpp>
-
-#include <xo/expression2/detail/IExpression_DIfElseExpr.hpp>
-#include <xo/expression2/detail/IGCObject_DIfElseExpr.hpp>
-#include <xo/expression2/detail/IPrintable_DIfElseExpr.hpp>
+#include <xo/expression2/LambdaExpr.hpp>
+#include <xo/expression2/IfElseExpr.hpp>
 
 #include <xo/expression2/detail/IExpression_DSequenceExpr.hpp>
 #include <xo/expression2/detail/IGCObject_DSequenceExpr.hpp>
 #include <xo/expression2/detail/IPrintable_DSequenceExpr.hpp>
 
-#include <xo/expression2/symtab/ISymbolTable_DLocalSymtab.hpp>
-//#include <xo/expression2/detail/IGCObject_DLocalSymtab.hpp>
-#include <xo/expression2/symtab/IPrintable_DLocalSymtab.hpp>
+#include <xo/expression2/LocalSymtab.hpp>
 
 #include <xo/gc/detail/AGCObject.hpp>
 #include <xo/printable2/detail/APrintable.hpp>
@@ -70,6 +58,10 @@ namespace xo {
             // +- IfElseExpr
             // \- SequenceExpr
 
+            // SymbolTable
+            // +- LocalSymtab
+            // \- GlobalSymtab
+
             FacetRegistry::register_impl<AExpression, DConstant>();
             FacetRegistry::register_impl<AGCObject, DConstant>();
             FacetRegistry::register_impl<APrintable, DConstant>();
@@ -91,7 +83,7 @@ namespace xo {
             FacetRegistry::register_impl<APrintable, DApplyExpr>();
 
             FacetRegistry::register_impl<AExpression, DLambdaExpr>();
-            //FacetRegistry::register_impl<AGCObject, DLambdaExpr>();
+            FacetRegistry::register_impl<AGCObject, DLambdaExpr>();
             FacetRegistry::register_impl<APrintable, DLambdaExpr>();
 
             FacetRegistry::register_impl<AExpression, DIfElseExpr>();
@@ -103,7 +95,7 @@ namespace xo {
             FacetRegistry::register_impl<APrintable, DSequenceExpr>();
 
             FacetRegistry::register_impl<ASymbolTable, DLocalSymtab>();
-            //FacetRegistry::register_impl<AGCObject, DLocalSymtab>();
+            FacetRegistry::register_impl<AGCObject, DLocalSymtab>();
             FacetRegistry::register_impl<APrintable, DLocalSymtab>();
 
             log && log(xtag("DUniqueString.tseq", typeseq::id<DUniqueString>()));