diff --git a/gtsam/inference/Permutation.cpp b/gtsam/inference/Permutation.cpp
index f94b4e116..883041b86 100644
--- a/gtsam/inference/Permutation.cpp
+++ b/gtsam/inference/Permutation.cpp
@@ -200,6 +200,13 @@ namespace internal {
       return it->second;
   }
 
+  /* ************************************************************************* */
+  void Reduction::print(const std::string& s) const {
+    cout << s << " reduction:" << endl;
+    BOOST_FOREACH(const value_type& p, *this)
+      cout << "  " << p.first << " : " << p.second << endl;
+  }
+
   /* ************************************************************************* */
   Permutation createReducingPermutation(const std::set<Index>& indices) {
     Permutation p(indices.size());
@@ -210,6 +217,7 @@ namespace internal {
     }
     return p;
   }
-}
+} // \namespace internal
 
-}
+/* ************************************************************************* */
+} // \namespace gtsam
diff --git a/gtsam/inference/Permutation.h b/gtsam/inference/Permutation.h
index 45fd4b377..6014d704e 100644
--- a/gtsam/inference/Permutation.h
+++ b/gtsam/inference/Permutation.h
@@ -189,11 +189,15 @@ namespace internal {
   // An internal class used for storing and applying a permutation from a map
   class Reduction : public gtsam::FastMap<Index,Index> {
   public:
+    typedef gtsam::FastMap<Index,Index> Base;
+
     static Reduction CreateAsInverse(const Permutation& p);
     void applyInverse(std::vector<Index>& js) const;
     Permutation inverse() const;
     Index& operator[](const Index& j);
     const Index& operator[](const Index& j) const;
+
+    void print(const std::string& s="") const;
   };
 
   // Reduce the variable indices so that those in the set are mapped to start at zero