diff --git a/gtsam/base/Matrix.cpp b/gtsam/base/Matrix.cpp
index 5b8a021..abc6574 100644
--- a/gtsam/base/Matrix.cpp
+++ b/gtsam/base/Matrix.cpp
@@ -127,16 +127,6 @@ bool linear_dependent(const Matrix& A, const Matrix& B, double tol) {
   }
 }
 
-/* ************************************************************************* */
-Vector operator^(const Matrix& A, const Vector & v) {
-  if (A.rows()!=v.size()) throw std::invalid_argument(
-      boost::str(boost::format("Matrix operator^ : A.m(%d)!=v.size(%d)") % A.rows() % v.size()));
-//  Vector vt = v.transpose();
-//  Vector vtA = vt * A;
-//  return vtA.transpose();
-  return A.transpose() * v;
-}
-
 const Eigen::IOFormat& matlabFormat() {
   static const Eigen::IOFormat matlab(
     Eigen::StreamPrecision, // precision
diff --git a/gtsam/base/Matrix.h b/gtsam/base/Matrix.h
index cfedf6d..05e3d0d 100644
--- a/gtsam/base/Matrix.h
+++ b/gtsam/base/Matrix.h
@@ -54,7 +54,7 @@ using Matrix7##N = Eigen::Matrix<double, 7, N>;  \
 using Matrix8##N = Eigen::Matrix<double, 8, N>;  \
 using Matrix9##N = Eigen::Matrix<double, 9, N>;  \
 static const Eigen::MatrixBase<Matrix##N>::IdentityReturnType I_##N##x##N = Matrix##N::Identity(); \
-static const Eigen::MatrixBase<Matrix##N>::ConstantReturnType Z_##N##x##N = Matrix##N::Zero();
+static const Eigen::MatrixBase<Matrix##N>::ZeroReturnType Z_##N##x##N = Matrix##N::Zero();
 
 GTSAM_MAKE_MATRIX_DEFS(1)
 GTSAM_MAKE_MATRIX_DEFS(2)
@@ -133,12 +133,6 @@ GTSAM_EXPORT bool linear_independent(const Matrix& A, const Matrix& B, double to
  */
 GTSAM_EXPORT bool linear_dependent(const Matrix& A, const Matrix& B, double tol = 1e-9);
 
-/**
- * overload ^ for trans(A)*v
- * We transpose the vectors for speed.
- */
-GTSAM_EXPORT Vector operator^(const Matrix& A, const Vector & v);
-
 /** products using old-style format to improve compatibility */
 template<class MATRIX>
 inline MATRIX prod(const MATRIX& A, const MATRIX&B) {
diff --git a/gtsam/base/Vector.h b/gtsam/base/Vector.h
index f7923ff..99573a5 100644
--- a/gtsam/base/Vector.h
+++ b/gtsam/base/Vector.h
@@ -27,6 +27,7 @@
 
 #include <gtsam/global_includes.h>
 #include <Eigen/Core>
+#include <cassert>
 #include <iosfwd>
 #include <list>
 
@@ -42,14 +43,14 @@ typedef Eigen::Matrix<double, 1, 1> Vector1;
 typedef Eigen::Vector2d Vector2;
 typedef Eigen::Vector3d Vector3;
 
-static const Eigen::MatrixBase<Vector2>::ConstantReturnType Z_2x1 = Vector2::Zero();
-static const Eigen::MatrixBase<Vector3>::ConstantReturnType Z_3x1 = Vector3::Zero();
+static const Eigen::MatrixBase<Vector2>::ZeroReturnType Z_2x1 = Vector2::Zero();
+static const Eigen::MatrixBase<Vector3>::ZeroReturnType Z_3x1 = Vector3::Zero();
 
 // Create handy typedefs and constants for vectors with N>3
 // VectorN and Z_Nx1, for N=1..9
 #define GTSAM_MAKE_VECTOR_DEFS(N)                \
   using Vector##N = Eigen::Matrix<double, N, 1>; \
-  static const Eigen::MatrixBase<Vector##N>::ConstantReturnType Z_##N##x1 = Vector##N::Zero();
+  static const Eigen::MatrixBase<Vector##N>::ZeroReturnType Z_##N##x1 = Vector##N::Zero();
 
 GTSAM_MAKE_VECTOR_DEFS(4)
 GTSAM_MAKE_VECTOR_DEFS(5)