diff --git a/gtsam_unstable/nonlinear/Expression-inl.h b/gtsam_unstable/nonlinear/Expression-inl.h
index 63b159e05..9f5a3ab90 100644
--- a/gtsam_unstable/nonlinear/Expression-inl.h
+++ b/gtsam_unstable/nonlinear/Expression-inl.h
@@ -19,17 +19,16 @@
 
 #pragma once
 
+#include <gtsam_unstable/nonlinear/Callrecord.h>
 #include <gtsam/nonlinear/Values.h>
-#include <gtsam/base/Matrix.h>
 #include <gtsam/base/Testable.h>
 #include <gtsam/base/Manifold.h>
-#include <gtsam/base/VerticalBlockMatrix.h>
 
 #include <boost/foreach.hpp>
 #include <boost/tuple/tuple.hpp>
 #include <boost/bind.hpp>
 
-// template meta-programming headers
+// template meta-programming headers, TODO not all needed?
 #include <boost/mpl/vector.hpp>
 #include <boost/mpl/plus.hpp>
 #include <boost/mpl/front.hpp>
@@ -40,8 +39,10 @@
 #include <boost/mpl/transform.hpp>
 #include <boost/mpl/at.hpp>
 namespace MPL = boost::mpl::placeholders;
+//
+//#include <new> // for placement new
+#include <map>
 
-#include <new> // for placement new
 class ExpressionFactorBinaryTest;
 // Forward declare for testing
 
@@ -71,121 +72,6 @@ public:
   }
 };
 
-//-----------------------------------------------------------------------------
-/**
- * MaxVirtualStaticRows defines how many separate virtual reverseAD with specific
- * static rows (1..MaxVirtualStaticRows) methods will be part of the CallRecord interface.
- */
-const int MaxVirtualStaticRows = 4;
-
-namespace internal {
-/**
- * ConvertToDynamicIf converts to a dense matrix with dynamic rows iff ConvertToDynamicRows (colums stay as they are) otherwise
- * it just passes dense Eigen matrices through.
- */
-template <bool ConvertToDynamicRows>
-struct ConvertToDynamicRowsIf {
-  template <typename Derived>
-  static Eigen::Matrix<double, Eigen::Dynamic, Derived::ColsAtCompileTime> convert(const Eigen::MatrixBase<Derived> & x){
-    return x;
-  }
-};
-template <>
-struct ConvertToDynamicRowsIf<false> {
-  template <int Rows, int Cols>
-  static const Eigen::Matrix<double, Rows, Cols> & convert(const Eigen::Matrix<double, Rows, Cols> & x){
-    return x;
-  }
-};
-
-/**
- * Recursive definition of an interface having several purely
- * virtual _reverseAD(const Eigen::Matrix<double, Rows, Cols> &, JacobianMap&)
- * with Rows in 1..MaxSupportedStaticRows
- */
-template<int MaxSupportedStaticRows, int Cols>
-struct ReverseADInterface : public ReverseADInterface < MaxSupportedStaticRows - 1, Cols> {
- protected:
-  using ReverseADInterface < MaxSupportedStaticRows - 1, Cols>::_reverseAD;
-  virtual void _reverseAD(const Eigen::Matrix<double, MaxSupportedStaticRows, Cols> & dFdT, JacobianMap& jacobians) const = 0;
-};
-
-template<int Cols>
-struct ReverseADInterface<0, Cols> {
- protected:
-  void _reverseAD(){} //dummy to allow the using directive in the template without failing for MaxSupportedStaticRows == 1.
-};
-}
-
-/**
- * The CallRecord class stores the Jacobians of applying a function
- * with respect to each of its arguments. It also stores an executation trace
- * (defined below) for each of its arguments.
- *
- * It is implemented in the function-style ExpressionNode's nested Record class below.
- */
-template<int Cols>
-struct CallRecord : private internal::ReverseADInterface<MaxVirtualStaticRows, Cols> {
-  inline void print(const std::string& indent) const {
-    _print(indent);
-  }
-  inline void startReverseAD(JacobianMap& jacobians) const {
-    _startReverseAD(jacobians);
-  }
-  template <int Rows>
-  inline void reverseAD(const Eigen::Matrix<double, Rows, Cols> & dFdT, JacobianMap& jacobians) const{
-    _reverseAD(internal::ConvertToDynamicRowsIf<(Rows > MaxVirtualStaticRows)>::convert(dFdT), jacobians);
-  }
-  virtual ~CallRecord() {
-  }
- private:
-  using internal::ReverseADInterface<MaxVirtualStaticRows, Cols>::_reverseAD;
-  virtual void _print(const std::string& indent) const = 0;
-  virtual void _startReverseAD(JacobianMap& jacobians) const = 0;
-  virtual void _reverseAD(const Eigen::Matrix<double, Eigen::Dynamic, Cols> & dFdT, JacobianMap& jacobians) const = 0;
-  virtual void _reverseAD(const Matrix & dFdT, JacobianMap& jacobians) const = 0;
-};
-
-namespace internal {
-/**
- * ReverseADImplementor is a utility class used by CallRecordImplementor to implementing the recursive CallRecord interface.
- */
-template <typename Derived, int MaxSupportedStaticRows, int Cols>
-struct ReverseADImplementor : ReverseADImplementor<Derived, MaxSupportedStaticRows - 1, Cols> {
- protected:
-  virtual void _reverseAD(const Eigen::Matrix<double, MaxSupportedStaticRows, Cols> & dFdT, JacobianMap& jacobians) const {
-    static_cast<const Derived *>(this)->reverseAD(dFdT, jacobians);
-  }
-};
-template<typename Derived, int Cols>
-struct ReverseADImplementor<Derived, 0, Cols> : CallRecord<Cols> {
-};
-
-/**
- * The CallRecordImplementor implements the CallRecord interface for a Derived class by
- * delegating to its corresponding (templated) non-virtual methods.
- */
-template<typename Derived, int Cols>
-struct CallRecordImplementor : public ReverseADImplementor<Derived, MaxVirtualStaticRows, Cols> {
- private:
-  const Derived & derived() const {
-    return static_cast<const Derived&>(*this);
-  }
-  virtual void _print(const std::string& indent) const {
-    derived().print(indent);
-  }
-  virtual void _startReverseAD(JacobianMap& jacobians) const {
-    derived().startReverseAD(jacobians);
-  }
-  virtual void _reverseAD(const Eigen::Matrix<double, Eigen::Dynamic, Cols> & dFdT, JacobianMap& jacobians) const {
-    derived().reverseAD(dFdT, jacobians);
-  }
-  virtual void _reverseAD(const Matrix & dFdT, JacobianMap& jacobians) const {
-    derived().reverseAD(dFdT, jacobians);
-  }
-};
-}
-
 //-----------------------------------------------------------------------------
 /// Handle Leaf Case: reverseAD ends here, by writing a matrix into Jacobians
 template<int ROWS, int COLS>