diff --git a/include/xo/expression2/define/IGCObject_DDefineExpr.hpp b/include/xo/expression2/define/IGCObject_DDefineExpr.hpp
index c07c8e4e..e98403fe 100644
--- a/include/xo/expression2/define/IGCObject_DDefineExpr.hpp
+++ b/include/xo/expression2/define/IGCObject_DDefineExpr.hpp
@@ -43,7 +43,6 @@ namespace xo {
             ///@{
             using size_type = xo::mm::AGCObject::size_type;
             using AAllocator = xo::mm::AGCObject::AAllocator;
-            using ACollector = xo::mm::AGCObject::ACollector;
             using AGCObjectVisitor = xo::mm::AGCObject::AGCObjectVisitor;
             using VisitReason = xo::mm::AGCObject::VisitReason;
             using Copaque = xo::mm::AGCObject::Copaque;
diff --git a/include/xo/expression2/detail/IExpression_Xfer.hpp b/include/xo/expression2/detail/IExpression_Xfer.hpp
index 095e21ed..c1e78815 100644
--- a/include/xo/expression2/detail/IExpression_Xfer.hpp
+++ b/include/xo/expression2/detail/IExpression_Xfer.hpp
@@ -9,10 +9,18 @@
  *       [iface_facet_any.hpp.j2]
  *  3. idl for facet methods
  *       [idl/Expression.json5]
+ *
+ *  variables:
+ *    {facet_hpp_fname} -> Expression.hpp
+ *    {impl_hpp_subdir} -> detail
+ *    {facet_ns1} -> xo
+ *    {facet_detail_subdir} -> detail
+ *    {abstract_facet_fname} -> AExpression.hpp
  **/
 
 #pragma once
 
+#include "AExpression.hpp"
 #include "TypeRef.hpp"
 #include "exprtype.hpp"
 #include <xo/reflect/TypeDescr.hpp>
diff --git a/include/xo/expression2/detail/IGCObject_DApplyExpr.hpp b/include/xo/expression2/detail/IGCObject_DApplyExpr.hpp
index a1a2fac4..9ce7cdda 100644
--- a/include/xo/expression2/detail/IGCObject_DApplyExpr.hpp
+++ b/include/xo/expression2/detail/IGCObject_DApplyExpr.hpp
@@ -43,7 +43,6 @@ namespace xo {
             ///@{
             using size_type = xo::mm::AGCObject::size_type;
             using AAllocator = xo::mm::AGCObject::AAllocator;
-            using ACollector = xo::mm::AGCObject::ACollector;
             using AGCObjectVisitor = xo::mm::AGCObject::AGCObjectVisitor;
             using VisitReason = xo::mm::AGCObject::VisitReason;
             using Copaque = xo::mm::AGCObject::Copaque;
diff --git a/include/xo/expression2/detail/IGCObject_DConstant.hpp b/include/xo/expression2/detail/IGCObject_DConstant.hpp
index 82783948..f5c9de84 100644
--- a/include/xo/expression2/detail/IGCObject_DConstant.hpp
+++ b/include/xo/expression2/detail/IGCObject_DConstant.hpp
@@ -43,7 +43,6 @@ namespace xo {
             ///@{
             using size_type = xo::mm::AGCObject::size_type;
             using AAllocator = xo::mm::AGCObject::AAllocator;
-            using ACollector = xo::mm::AGCObject::ACollector;
             using AGCObjectVisitor = xo::mm::AGCObject::AGCObjectVisitor;
             using VisitReason = xo::mm::AGCObject::VisitReason;
             using Copaque = xo::mm::AGCObject::Copaque;
diff --git a/include/xo/expression2/detail/IGCObject_DIfElseExpr.hpp b/include/xo/expression2/detail/IGCObject_DIfElseExpr.hpp
index 3156fe58..ad5862a2 100644
--- a/include/xo/expression2/detail/IGCObject_DIfElseExpr.hpp
+++ b/include/xo/expression2/detail/IGCObject_DIfElseExpr.hpp
@@ -43,7 +43,6 @@ namespace xo {
             ///@{
             using size_type = xo::mm::AGCObject::size_type;
             using AAllocator = xo::mm::AGCObject::AAllocator;
-            using ACollector = xo::mm::AGCObject::ACollector;
             using AGCObjectVisitor = xo::mm::AGCObject::AGCObjectVisitor;
             using VisitReason = xo::mm::AGCObject::VisitReason;
             using Copaque = xo::mm::AGCObject::Copaque;
diff --git a/include/xo/expression2/detail/IGCObject_DLambdaExpr.hpp b/include/xo/expression2/detail/IGCObject_DLambdaExpr.hpp
index ec4faded..71b37d58 100644
--- a/include/xo/expression2/detail/IGCObject_DLambdaExpr.hpp
+++ b/include/xo/expression2/detail/IGCObject_DLambdaExpr.hpp
@@ -43,7 +43,6 @@ namespace xo {
             ///@{
             using size_type = xo::mm::AGCObject::size_type;
             using AAllocator = xo::mm::AGCObject::AAllocator;
-            using ACollector = xo::mm::AGCObject::ACollector;
             using AGCObjectVisitor = xo::mm::AGCObject::AGCObjectVisitor;
             using VisitReason = xo::mm::AGCObject::VisitReason;
             using Copaque = xo::mm::AGCObject::Copaque;
diff --git a/include/xo/expression2/detail/IGCObject_DSequenceExpr.hpp b/include/xo/expression2/detail/IGCObject_DSequenceExpr.hpp
index 1b927e01..d11f6341 100644
--- a/include/xo/expression2/detail/IGCObject_DSequenceExpr.hpp
+++ b/include/xo/expression2/detail/IGCObject_DSequenceExpr.hpp
@@ -43,7 +43,6 @@ namespace xo {
             ///@{
             using size_type = xo::mm::AGCObject::size_type;
             using AAllocator = xo::mm::AGCObject::AAllocator;
-            using ACollector = xo::mm::AGCObject::ACollector;
             using AGCObjectVisitor = xo::mm::AGCObject::AGCObjectVisitor;
             using VisitReason = xo::mm::AGCObject::VisitReason;
             using Copaque = xo::mm::AGCObject::Copaque;
diff --git a/include/xo/expression2/detail/IGCObject_DVarRef.hpp b/include/xo/expression2/detail/IGCObject_DVarRef.hpp
index 085999f9..9b3172d8 100644
--- a/include/xo/expression2/detail/IGCObject_DVarRef.hpp
+++ b/include/xo/expression2/detail/IGCObject_DVarRef.hpp
@@ -43,7 +43,6 @@ namespace xo {
             ///@{
             using size_type = xo::mm::AGCObject::size_type;
             using AAllocator = xo::mm::AGCObject::AAllocator;
-            using ACollector = xo::mm::AGCObject::ACollector;
             using AGCObjectVisitor = xo::mm::AGCObject::AGCObjectVisitor;
             using VisitReason = xo::mm::AGCObject::VisitReason;
             using Copaque = xo::mm::AGCObject::Copaque;
diff --git a/include/xo/expression2/symtab/IGCObject_DGlobalSymtab.hpp b/include/xo/expression2/symtab/IGCObject_DGlobalSymtab.hpp
index ee24adfb..0731ab56 100644
--- a/include/xo/expression2/symtab/IGCObject_DGlobalSymtab.hpp
+++ b/include/xo/expression2/symtab/IGCObject_DGlobalSymtab.hpp
@@ -43,7 +43,6 @@ namespace xo {
             ///@{
             using size_type = xo::mm::AGCObject::size_type;
             using AAllocator = xo::mm::AGCObject::AAllocator;
-            using ACollector = xo::mm::AGCObject::ACollector;
             using AGCObjectVisitor = xo::mm::AGCObject::AGCObjectVisitor;
             using VisitReason = xo::mm::AGCObject::VisitReason;
             using Copaque = xo::mm::AGCObject::Copaque;
diff --git a/include/xo/expression2/symtab/IGCObject_DLocalSymtab.hpp b/include/xo/expression2/symtab/IGCObject_DLocalSymtab.hpp
index cbd98904..92226d63 100644
--- a/include/xo/expression2/symtab/IGCObject_DLocalSymtab.hpp
+++ b/include/xo/expression2/symtab/IGCObject_DLocalSymtab.hpp
@@ -43,7 +43,6 @@ namespace xo {
             ///@{
             using size_type = xo::mm::AGCObject::size_type;
             using AAllocator = xo::mm::AGCObject::AAllocator;
-            using ACollector = xo::mm::AGCObject::ACollector;
             using AGCObjectVisitor = xo::mm::AGCObject::AGCObjectVisitor;
             using VisitReason = xo::mm::AGCObject::VisitReason;
             using Copaque = xo::mm::AGCObject::Copaque;
diff --git a/include/xo/expression2/symtab/ISymbolTable_Xfer.hpp b/include/xo/expression2/symtab/ISymbolTable_Xfer.hpp
index db81237f..03b32ada 100644
--- a/include/xo/expression2/symtab/ISymbolTable_Xfer.hpp
+++ b/include/xo/expression2/symtab/ISymbolTable_Xfer.hpp
@@ -9,10 +9,18 @@
  *       [iface_facet_any.hpp.j2]
  *  3. idl for facet methods
  *       [idl/SymbolTable.json5]
+ *
+ *  variables:
+ *    {facet_hpp_fname} -> SymbolTable.hpp
+ *    {impl_hpp_subdir} -> symtab
+ *    {facet_ns1} -> xo
+ *    {facet_detail_subdir} -> symtab
+ *    {abstract_facet_fname} -> ASymbolTable.hpp
  **/
 
 #pragma once
 
+#include "ASymbolTable.hpp"
 #include "Binding.hpp"
 #include "DUniqueString.hpp"
 
diff --git a/include/xo/expression2/typename/IGCObject_DTypename.hpp b/include/xo/expression2/typename/IGCObject_DTypename.hpp
index cdd91734..14c0f336 100644
--- a/include/xo/expression2/typename/IGCObject_DTypename.hpp
+++ b/include/xo/expression2/typename/IGCObject_DTypename.hpp
@@ -41,7 +41,6 @@ namespace xo {
             ///@{
             using size_type = xo::mm::AGCObject::size_type;
             using AAllocator = xo::mm::AGCObject::AAllocator;
-            using ACollector = xo::mm::AGCObject::ACollector;
             using AGCObjectVisitor = xo::mm::AGCObject::AGCObjectVisitor;
             using VisitReason = xo::mm::AGCObject::VisitReason;
             using Copaque = xo::mm::AGCObject::Copaque;
diff --git a/include/xo/expression2/variable/IGCObject_DVariable.hpp b/include/xo/expression2/variable/IGCObject_DVariable.hpp
index 9e173090..fbb60525 100644
--- a/include/xo/expression2/variable/IGCObject_DVariable.hpp
+++ b/include/xo/expression2/variable/IGCObject_DVariable.hpp
@@ -43,7 +43,6 @@ namespace xo {
             ///@{
             using size_type = xo::mm::AGCObject::size_type;
             using AAllocator = xo::mm::AGCObject::AAllocator;
-            using ACollector = xo::mm::AGCObject::ACollector;
             using AGCObjectVisitor = xo::mm::AGCObject::AGCObjectVisitor;
             using VisitReason = xo::mm::AGCObject::VisitReason;
             using Copaque = xo::mm::AGCObject::Copaque;