diff --git a/gtsam_unstable/nonlinear/Expression-inl.h b/gtsam_unstable/nonlinear/Expression-inl.h
index cd4bc68a7..308f03297 100644
--- a/gtsam_unstable/nonlinear/Expression-inl.h
+++ b/gtsam_unstable/nonlinear/Expression-inl.h
@@ -20,6 +20,7 @@
 #pragma once
 
 #include <gtsam/nonlinear/Values.h>
+#include <gtsam/base/Matrix.h>
 #include <boost/foreach.hpp>
 
 namespace gtsam {
diff --git a/gtsam_unstable/nonlinear/tests/testBADFactor.cpp b/gtsam_unstable/nonlinear/tests/testBADFactor.cpp
index b4960afcd..6cadc4f63 100644
--- a/gtsam_unstable/nonlinear/tests/testBADFactor.cpp
+++ b/gtsam_unstable/nonlinear/tests/testBADFactor.cpp
@@ -17,10 +17,11 @@
  * @brief unit tests for Block Automatic Differentiation
  */
 
+#include <gtsam_unstable/slam/expressions.h>
+#include <gtsam_unstable/nonlinear/BADFactor.h>
 #include <gtsam/slam/GeneralSFMFactor.h>
 #include <gtsam/geometry/Pose3.h>
 #include <gtsam/geometry/Cal3_S2.h>
-#include <gtsam_unstable/nonlinear/BADFactor.h>
 #include <gtsam/base/Testable.h>
 
 #include <CppUnitLite/TestHarness.h>
@@ -28,31 +29,6 @@
 using namespace std;
 using namespace gtsam;
 
-/* ************************************************************************* */
-// Proposed naming convention
-/* ************************************************************************* */
-typedef Expression<Point2> Point2_;
-typedef Expression<Point3> Point3_;
-typedef Expression<Rot3> Rot3_;
-typedef Expression<Pose3> Pose3_;
-typedef Expression<Cal3_S2> Cal3_S2_;
-
-/* ************************************************************************* */
-// Functions that allow creating concise expressions
-/* ************************************************************************* */
-Point3_ transform_to(const Pose3_& x, const Point3_& p) {
-  return Point3_(x, &Pose3::transform_to, p);
-}
-
-Point2_ project(const Point3_& p_cam) {
-  return Point2_(PinholeCamera<Cal3_S2>::project_to_camera, p_cam);
-}
-
-template<class CAL>
-Point2_ uncalibrate(const Expression<CAL>& K, const Point2_& xy_hat) {
-  return Point2_(K, &CAL::uncalibrate, xy_hat);
-}
-
 /* ************************************************************************* */
 
 TEST(BADFactor, test) {
diff --git a/gtsam_unstable/slam/expressions.h b/gtsam_unstable/slam/expressions.h
new file mode 100644
index 000000000..406456f50
--- /dev/null
+++ b/gtsam_unstable/slam/expressions.h
@@ -0,0 +1,36 @@
+/**
+ * @file expressions.h
+ * @brief Common expressions for solving geometry/slam/sfm problems
+ * @date Oct 1, 2014
+ * @author Frank Dellaert
+ */
+
+#pragma once
+
+#include <gtsam_unstable/nonlinear/Expression.h>
+#include <gtsam/geometry/Cal3_S2.h>
+#include <gtsam/geometry/PinholeCamera.h>
+
+namespace gtsam {
+
+typedef Expression<Point2> Point2_;
+typedef Expression<Point3> Point3_;
+typedef Expression<Rot3> Rot3_;
+typedef Expression<Pose3> Pose3_;
+typedef Expression<Cal3_S2> Cal3_S2_;
+
+Point3_ transform_to(const Pose3_& x, const Point3_& p) {
+  return Point3_(x, &Pose3::transform_to, p);
+}
+
+Point2_ project(const Point3_& p_cam) {
+  return Point2_(PinholeCamera<Cal3_S2>::project_to_camera, p_cam);
+}
+
+template<class CAL>
+Point2_ uncalibrate(const Expression<CAL>& K, const Point2_& xy_hat) {
+  return Point2_(K, &CAL::uncalibrate, xy_hat);
+}
+
+} // \namespace gtsam
+