diff --git a/examples/Pose2SLAMExample.cpp b/examples/Pose2SLAMExample.cpp
index 44cbd29a4..776665cbf 100644
--- a/examples/Pose2SLAMExample.cpp
+++ b/examples/Pose2SLAMExample.cpp
@@ -71,7 +71,7 @@ int main(int argc, char** argv) {
 
 	/* 4.2.1 Alternatively, you can go through the process step by step
 	 * Choose an ordering */
-	Ordering::shared_ptr ordering = graph->orderingCOLAMD(*initialEstimate).first;
+	Ordering::shared_ptr ordering = graph->orderingCOLAMD(*initialEstimate);
 
   /* 4.2.2 set up solver and optimize */
 	Optimizer::shared_solver solver(new Optimizer::solver(ordering));
diff --git a/inference/EliminationTree-inl.h b/inference/EliminationTree-inl.h
new file mode 100644
index 000000000..e9f7a4dc7
--- /dev/null
+++ b/inference/EliminationTree-inl.h
@@ -0,0 +1,159 @@
+/**
+ * @file    EliminationTree.cpp
+ * @brief   
+ * @author  Frank Dellaert
+ * @created Oct 13, 2010
+ */
+
+#include <gtsam/inference/EliminationTree.h>
+#include <gtsam/inference/VariableSlots-inl.h>
+
+#include <boost/foreach.hpp>
+#include <boost/lambda/lambda.hpp>
+#include <iostream>
+#include <set>
+#include <vector>
+
+using namespace std;
+
+namespace gtsam {
+
+/* ************************************************************************* */
+template<class FACTORGRAPH>
+typename EliminationTree<FACTORGRAPH>::EliminationResult
+EliminationTree<FACTORGRAPH>::eliminate_() const {
+
+  typename FACTORGRAPH::bayesnet_type bayesNet;
+
+  set<Index, std::less<Index>, boost::fast_pool_allocator<Index> > separator;
+
+  // Create the list of factors to be eliminated
+  FACTORGRAPH factors;
+  factors.reserve(this->factors_.size() + this->subTrees_.size());
+
+  // add all factors associated with root
+  factors.push_back(this->factors_.begin(), this->factors_.end());
+
+  // for all children, eliminate into Bayes net and add the eliminated factors
+  BOOST_FOREACH(const shared_ptr& child, subTrees_) {
+    EliminationResult result = child->eliminate_();
+    bayesNet.push_back(result.first);
+    factors.push_back(result.second);
+  }
+
+  // eliminate the joint factor and add the conditional to the bayes net
+  typename FACTORGRAPH::sharedFactor jointFactor(FACTORGRAPH::factor_type::Combine(factors, VariableSlots(factors)));
+  bayesNet.push_back(jointFactor->eliminateFirst());
+
+  return EliminationResult(bayesNet, jointFactor);
+}
+
+/* ************************************************************************* */
+template<class FACTORGRAPH>
+vector<Index> EliminationTree<FACTORGRAPH>::ComputeParents(const VariableIndex<>& structure) {
+
+  // Number of factors and variables
+  const size_t m = structure.nFactors();
+  const size_t n = structure.size();
+
+  static const Index none = numeric_limits<Index>::max();
+
+  // Allocate result parent vector and vector of last factor columns
+  vector<Index> parents(n, none);
+  vector<Index> prevCol(m, none);
+
+  // for column j \in 1 to n do
+  for (Index j = 0; j < n; j++) {
+    // for row i \in Struct[A*j] do
+    BOOST_FOREACH(typename VariableIndex<>::mapped_factor_type i_pos, structure[j]) {
+      const size_t i = i_pos.factorIndex;
+      if (prevCol[i] != none) {
+        Index k = prevCol[i];
+        // find root r of the current tree that contains k
+        Index r = k;
+        while (parents[r] != none)
+          r = parents[r];
+        if (r != j) parents[r] = j;
+      }
+      prevCol[i] = j;
+    }
+  }
+
+  return parents;
+}
+
+/* ************************************************************************* */
+template<class FACTORGRAPH>
+typename EliminationTree<FACTORGRAPH>::shared_ptr
+EliminationTree<FACTORGRAPH>::Create(const FACTORGRAPH& factorGraph) {
+
+  // Create column structure
+  VariableIndex<> varIndex(factorGraph);
+
+  // Compute the tree structure
+  vector<Index> parents(ComputeParents(varIndex));
+
+  // Number of variables
+  const size_t n = varIndex.size();
+
+  static const Index none = numeric_limits<Index>::max();
+
+  // Create tree structure
+  vector<shared_ptr> trees(n);
+  for (Index k = 1; k <= n; k++) {
+    Index j = n - k;
+    trees[j].reset(new EliminationTree(j));
+    if (parents[j] != none)
+      trees[parents[j]]->add(trees[j]);
+  }
+
+  // Hang factors in right places
+  BOOST_FOREACH(const sharedFactor& factor, factorGraph) {
+    Index j = factor->front();
+    trees[j]->add(factor);
+  }
+
+  // Assert that all other nodes have parents, i.e. that this is not a forest.
+#ifndef NDEBUG
+  for(typename vector<shared_ptr>::const_iterator tree=trees.begin(); tree!=trees.end()-1; ++tree)
+    assert((*tree) != shared_ptr());
+#endif
+
+  return trees.back();
+}
+
+/* ************************************************************************* */
+template<class FACTORGRAPH>
+void EliminationTree<FACTORGRAPH>::print(const std::string& name) const {
+  cout << name << " (" << key_ << ")" << endl;
+  BOOST_FOREACH(const sharedFactor& factor, factors_) {
+    factor->print(name + "  "); }
+  BOOST_FOREACH(const shared_ptr& child, subTrees_) {
+    child->print(name + "  "); }
+}
+
+/* ************************************************************************* */
+template<class FACTORGRAPH>
+bool EliminationTree<FACTORGRAPH>::equals(const EliminationTree<FACTORGRAPH>& expected, double tol) const {
+  if(this->key_ == expected.key_ && this->factors_ == expected.factors_
+      && this->subTrees_.size() == expected.subTrees_.size()) {
+    typename SubTrees::const_iterator this_subtree = this->subTrees_.begin();
+    typename SubTrees::const_iterator expected_subtree = expected.subTrees_.begin();
+    while(this_subtree != this->subTrees_.end())
+      if( ! (*(this_subtree++))->equals(**(expected_subtree++), tol))
+        return false;
+    return true;
+  } else
+    return false;
+}
+
+/* ************************************************************************* */
+template<class FACTORGRAPH>
+typename FACTORGRAPH::bayesnet_type::shared_ptr EliminationTree<FACTORGRAPH>::eliminate() const {
+
+  // call recursive routine
+  EliminationResult result = eliminate_();
+  return typename FACTORGRAPH::bayesnet_type::shared_ptr(new typename FACTORGRAPH::bayesnet_type(result.first));
+}
+
+}
diff --git a/inference/EliminationTree.h b/inference/EliminationTree.h
new file mode 100644
index 000000000..f2478bd2e
--- /dev/null
+++ b/inference/EliminationTree.h
@@ -0,0 +1,81 @@
+/**
+ * @file    EliminationTree.h
+ * @brief   
+ * @author  Frank Dellaert
+ * @created Oct 13, 2010
+ */
+#pragma once
+
+#include <list>
+#include <string>
+#include <utility>
+#include <boost/pool/pool_alloc.hpp>
+
+#include <gtsam/inference/VariableIndex.h>
+
+class EliminationTreeTester; // for unit tests, see testEliminationTree
+
+namespace gtsam {
+
+/**
+ * An elimination tree is a tree of factors
+ */
+template<class FACTORGRAPH>
+class EliminationTree: public Testable<EliminationTree<FACTORGRAPH> > {
+
+public:
+
+  typedef boost::shared_ptr<typename FACTORGRAPH::factor_type> sharedFactor;
+  typedef boost::shared_ptr<EliminationTree<FACTORGRAPH> > shared_ptr;
+  typedef FACTORGRAPH FactorGraph;
+
+private:
+
+  typedef std::list<sharedFactor, boost::fast_pool_allocator<sharedFactor> > Factors;
+  typedef std::list<shared_ptr, boost::fast_pool_allocator<shared_ptr> > SubTrees;
+
+  Index key_; /** index associated with root */
+  Factors factors_; /** factors associated with root */
+  SubTrees subTrees_; /** sub-trees */
+
+  typedef std::pair<typename FACTORGRAPH::bayesnet_type, typename FACTORGRAPH::sharedFactor> EliminationResult;
+
+  /** default constructor, private, as you should use Create below */
+  EliminationTree(Index key = 0) : key_(key) {}
+
+  /** add a factor, for Create use only */
+  void add(const sharedFactor& factor) { factors_.push_back(factor); }
+
+  /** add a subtree, for Create use only */
+  void add(const shared_ptr& child) { subTrees_.push_back(child); }
+
+  /**
+   * Static internal function to build a vector of parent pointers using the
+   * algorithm of Gilbert et al., 2001, BIT.
+   */
+  static std::vector<Index> ComputeParents(const VariableIndex<>& structure);
+
+  /**
+   * Recursive routine that eliminates the factors arranged in an elimination tree
+   */
+  EliminationResult eliminate_() const;
+
+  // Allow access to constructor and add methods for testing purposes
+  friend class ::EliminationTreeTester;
+
+public:
+
+  /** Named constructor to build the elimination tree of a factor graph */
+  static shared_ptr Create(const FACTORGRAPH& factorGraph);
+
+  /** Print the tree to cout */
+  void print(const std::string& name = "EliminationTree: ") const;
+
+  /** Test whether the tree is equal to another */
+  bool equals(const EliminationTree& other, double tol = 1e-9) const;
+
+  /** Eliminate the factors to a Bayes Net */
+  typename FACTORGRAPH::bayesnet_type::shared_ptr eliminate() const;
+};
+
+}
diff --git a/inference/FactorGraph.h b/inference/FactorGraph.h
index 8043ab5ea..d898d0755 100644
--- a/inference/FactorGraph.h
+++ b/inference/FactorGraph.h
@@ -85,6 +85,10 @@ namespace gtsam {
 		/** push back many factors */
 		void push_back(const FactorGraph<Factor>& factors);
 
+		/** push back many factors with an iterator */
+		template<typename Iterator>
+		void push_back(Iterator firstFactor, Iterator lastFactor);
+
 		/** ------------------ Querying Factor Graphs ---------------------------- */
 
 		/** print out graph */
@@ -249,6 +253,14 @@ namespace gtsam {
 #endif
   }
 
+  /* ************************************************************************* */
+  template<class Factor>
+  template<typename Iterator>
+  void FactorGraph<Factor>::push_back(Iterator firstFactor, Iterator lastFactor) {
+    Iterator factor = firstFactor;
+    while(factor != lastFactor)
+      this->push_back(*(factor++));
+  }
 
 } // namespace gtsam
 
diff --git a/inference/Makefile.am b/inference/Makefile.am
index 440b7284a..e8d9530c7 100644
--- a/inference/Makefile.am
+++ b/inference/Makefile.am
@@ -30,7 +30,7 @@ headers += VariableIndex.h
 headers += FactorGraph.h FactorGraph-inl.h
 headers += ClusterTree.h ClusterTree-inl.h
 headers += JunctionTree.h JunctionTree-inl.h
-#headers += EliminationTree.h EliminationTree-inl.h
+headers += EliminationTree.h EliminationTree-inl.h
 headers += BayesNet.h BayesNet-inl.h
 headers += BayesTree.h BayesTree-inl.h
 headers += ISAM.h ISAM-inl.h
@@ -38,7 +38,7 @@ check_PROGRAMS += tests/testFactorGraph
 check_PROGRAMS += tests/testFactorGraph
 check_PROGRAMS += tests/testBayesTree 
 check_PROGRAMS += tests/testISAM
-#check_PROGRAMS += tests/testEliminationTree
+check_PROGRAMS += tests/testEliminationTree
 check_PROGRAMS += tests/testClusterTree
 check_PROGRAMS += tests/testJunctionTree
 
diff --git a/inference/SymbolicFactorGraph.cpp b/inference/SymbolicFactorGraph.cpp
index 8c6af7b6b..428b25779 100644
--- a/inference/SymbolicFactorGraph.cpp
+++ b/inference/SymbolicFactorGraph.cpp
@@ -24,6 +24,7 @@
 #include <gtsam/inference/BayesNet-inl.h>
 #include <gtsam/inference/Factor-inl.h>
 #include <gtsam/inference/inference-inl.h>
+#include <gtsam/inference/EliminationTree-inl.h>
 
 using namespace std;
 
@@ -32,6 +33,7 @@ namespace gtsam {
 	// Explicitly instantiate so we don't have to include everywhere
 	template class FactorGraph<Factor>;
 	template class BayesNet<Conditional>;
+	template class EliminationTree<SymbolicFactorGraph>;
 
   /* ************************************************************************* */
 	SymbolicFactorGraph::SymbolicFactorGraph(const BayesNet<Conditional>& bayesNet) :
diff --git a/inference/VariableIndex.h b/inference/VariableIndex.h
index 6089f547e..26517fd0e 100644
--- a/inference/VariableIndex.h
+++ b/inference/VariableIndex.h
@@ -80,7 +80,6 @@ public:
   const mapped_type& operator[](Index variable) const { checkVar(variable); return index_[variable]; }
   mapped_type& operator[](Index variable) { checkVar(variable); return index_[variable]; }
   void permute(const Permutation& permutation);
-//  template<class Derived> void augment(const Derived& varIndex);
   template<class FactorGraph> void augment(const FactorGraph& factorGraph);
   void rebaseFactors(ptrdiff_t baseIndexChange);
 
@@ -154,21 +153,6 @@ VariableIndex<Storage>::VariableIndex(const FactorGraph& factorGraph) :
   }
 }
 
-///* ************************************************************************* */
-//template<class Storage>
-//template<class Derived>
-//void VariableIndex<Storage>::augment(const Derived& varIndex) {
-//  nFactors_ = std::max(nFactors_, varIndex.nFactors());
-//  nEntries_ = nEntries_ + varIndex.nEntries();
-//  Index originalSize = index_.size();
-//  index_.container().resize(std::max(index_.size(), varIndex.size()));
-//  index_.permutation().resize(index_.container().size());
-//  for(Index var=originalSize; var<index_.permutation().size(); ++var)
-//    index_.permutation()[var] = var;
-//  for(Index var=0; var<varIndex.size(); ++var)
-//    index_[var].insert(index_[var].begin(), varIndex[var].begin(), varIndex[var].end());
-//}
-
 /* ************************************************************************* */
 template<class Storage>
 template<class FactorGraph>
diff --git a/inference/tests/testEliminationTree.cpp b/inference/tests/testEliminationTree.cpp
new file mode 100644
index 000000000..114827f60
--- /dev/null
+++ b/inference/tests/testEliminationTree.cpp
@@ -0,0 +1,104 @@
+/**
+ * @file    testEliminationTree.cpp
+ * @brief   
+ * @author  Richard Roberts
+ * @created Oct 14, 2010
+ */
+
+#include <gtsam/CppUnitLite/TestHarness.h>
+#include <gtsam/base/TestableAssertions.h>
+
+#include <gtsam/inference/EliminationTree.h>
+#include <gtsam/inference/SymbolicFactorGraph.h>
+
+using namespace gtsam;
+using namespace std;
+
+typedef EliminationTree<SymbolicFactorGraph> SymbolicEliminationTree;
+
+struct EliminationTreeTester {
+  // build hardcoded tree
+  static SymbolicEliminationTree::shared_ptr buildHardcodedTree(const SymbolicFactorGraph& fg) {
+
+    SymbolicEliminationTree::shared_ptr leaf0(new SymbolicEliminationTree);
+    leaf0->add(fg[0]);
+    leaf0->add(fg[1]);
+
+    SymbolicEliminationTree::shared_ptr node1(new SymbolicEliminationTree(1));
+    node1->add(fg[2]);
+    node1->add(leaf0);
+
+    SymbolicEliminationTree::shared_ptr node2(new SymbolicEliminationTree(2));
+    node2->add(fg[3]);
+    node2->add(node1);
+
+    SymbolicEliminationTree::shared_ptr leaf3(new SymbolicEliminationTree(3));
+    leaf3->add(fg[4]);
+
+    SymbolicEliminationTree::shared_ptr etree(new SymbolicEliminationTree(4));
+    etree->add(leaf3);
+    etree->add(node2);
+
+    return etree;
+  }
+};
+
+TEST(EliminationTree, Create)
+{
+  // create example factor graph
+  SymbolicFactorGraph fg;
+  fg.push_factor(0, 1);
+  fg.push_factor(0, 2);
+  fg.push_factor(1, 4);
+  fg.push_factor(2, 4);
+  fg.push_factor(3, 4);
+
+  SymbolicEliminationTree::shared_ptr expected = EliminationTreeTester::buildHardcodedTree(fg);
+
+  // Build from factor graph
+  SymbolicEliminationTree::shared_ptr actual = SymbolicEliminationTree::Create(fg);
+
+  CHECK(assert_equal(*expected,*actual));
+}
+
+/* ************************************************************************* */
+// Test to drive elimination tree development
+// graph: f(0,1) f(0,2) f(1,4) f(2,4) f(3,4)
+/* ************************************************************************* */
+
+TEST(EliminationTree, eliminate )
+{
+  // create expected Chordal bayes Net
+  Conditional::shared_ptr c0(new Conditional(0, 1, 2));
+  Conditional::shared_ptr c1(new Conditional(1, 2, 4));
+  Conditional::shared_ptr c2(new Conditional(2, 4));
+  Conditional::shared_ptr c3(new Conditional(3, 4));
+  Conditional::shared_ptr c4(new Conditional(4));
+
+  SymbolicBayesNet expected;
+  expected.push_back(c3);
+  expected.push_back(c0);
+  expected.push_back(c1);
+  expected.push_back(c2);
+  expected.push_back(c4);
+
+  // Create factor graph
+  SymbolicFactorGraph fg;
+  fg.push_factor(0, 1);
+  fg.push_factor(0, 2);
+  fg.push_factor(1, 4);
+  fg.push_factor(2, 4);
+  fg.push_factor(3, 4);
+
+  // eliminate
+  SymbolicBayesNet actual = *SymbolicEliminationTree::Create(fg)->eliminate();
+
+  CHECK(assert_equal(expected,actual));
+}
+
+/* ************************************************************************* */
+int main() {
+  TestResult tr;
+  return TestRegistry::runAllTests(tr);
+}
+/* ************************************************************************* */
diff --git a/inference/tests/testSymbolicFactorGraph.cpp b/inference/tests/testSymbolicFactorGraph.cpp
index 910b20faf..3984940f9 100644
--- a/inference/tests/testSymbolicFactorGraph.cpp
+++ b/inference/tests/testSymbolicFactorGraph.cpp
@@ -102,297 +102,296 @@ TEST( SymbolicFactorGraph, push_back )
 
 /* ************************************************************************* */
 
-/**
- * An elimination tree is a tree of factors
- */
-class ETree: public Testable<ETree> {
+///**
+// * An elimination tree is a tree of factors
+// */
+//class ETree: public Testable<ETree> {
+//
+//public:
+//
+//	typedef boost::shared_ptr<Factor> sharedFactor;
+//	typedef boost::shared_ptr<ETree> shared_ptr;
+//
+//private:
+//
+//	Index key_; /** index associated with root */
+//	list<sharedFactor> factors_; /** factors associated with root */
+//	list<shared_ptr> subTrees_; /** sub-trees */
+//
+//	typedef pair<SymbolicBayesNet, Factor> Result;
+//
+//	/**
+//	 * Recursive routine that eliminates the factors arranged in an elimination tree
+//	 */
+//	Result eliminate_() const {
+//
+//	  SymbolicBayesNet bn;
+//
+//	  set<Index> separator;
+//
+//	  // loop over all factors associated with root
+//	  // and set-union their keys to a separator
+//	  BOOST_FOREACH(const sharedFactor& factor, factors_)
+//	  BOOST_FOREACH(Index key, *factor) {
+//	    if (key != key_) separator.insert(key); }
+//
+//	  // for all children, eliminate into Bayes net
+//	  BOOST_FOREACH(const shared_ptr& child, subTrees_) {
+//	    Result result = child->eliminate_();
+//	    bn.push_back(result.first);
+//	    BOOST_FOREACH(Index key, result.second)
+//	    if (key != key_) separator.insert(key);
+//	  }
+//
+//	  // Make the conditional from the key and separator, and insert it in Bayes net
+//	  vector<Index> parents;
+//	  std::copy(separator.begin(), separator.end(), back_inserter(parents));
+//	  Conditional::shared_ptr conditional(new Conditional(key_, parents));
+//	  bn.push_back(conditional);
+//
+//	  // now create the new factor from separator to return to caller
+//	  Factor newFactor(separator.begin(), separator.end());
+//	  return Result(bn, newFactor);
+//	}
+//
+//public:
+//
+//	/** default constructor */
+//	ETree(Index key = 0) :
+//		key_(key) {
+//	}
+//
+//	/** add a factor */
+//	void add(const sharedFactor& factor) {
+//		factors_.push_back(factor);
+//	}
+//
+//	/** add a subtree */
+//	void add(const shared_ptr& child) {
+//		subTrees_.push_back(child);
+//	}
+//
+//	void print(const std::string& name) const {
+//		cout << name << " (" << key_ << ")" << endl;
+//		BOOST_FOREACH(const sharedFactor& factor, factors_)
+//						factor->print(name + "  ");
+//		BOOST_FOREACH(const shared_ptr& child, subTrees_)
+//						child->print(name + "  ");
+//	}
+//
+//	bool equals(const ETree& expected, double tol) const {
+//		// todo
+//		return false;
+//	}
+//
+//	/**
+//	 * Eliminate the factors to a Bayes Net
+//	 */
+//	SymbolicBayesNet eliminate() const {
+//
+//		// call recursive routine
+//		Result result = eliminate_();
+//		return result.first;
+//	}
+//
+//};
+//
+//// build hardcoded tree
+//ETree::shared_ptr buildHardcodedTree(const SymbolicFactorGraph& fg) {
+//
+//	ETree::shared_ptr leaf0(new ETree);
+//	leaf0->add(fg[0]);
+//	leaf0->add(fg[1]);
+//
+//	ETree::shared_ptr node1(new ETree(1));
+//	node1->add(fg[2]);
+//	node1->add(leaf0);
+//
+//	ETree::shared_ptr node2(new ETree(2));
+//	node2->add(fg[3]);
+//	node2->add(node1);
+//
+//	ETree::shared_ptr leaf3(new ETree(3));
+//	leaf3->add(fg[4]);
+//
+//	ETree::shared_ptr etree(new ETree(4));
+//	etree->add(leaf3);
+//	etree->add(node2);
+//
+//	return etree;
+//}
+//
+//typedef size_t RowIndex;
+//typedef vector<list<RowIndex> > StructA;
+//typedef vector<boost::optional<Index> > optionalIndices;
+//
+///**
+// * Gilbert01bit algorithm in Figure 2.2
+// */
+//optionalIndices buildETree(const StructA& structA) {
+//
+//  // todo: get n
+//  size_t n = 5;
+//  optionalIndices parent(n);
+//
+//  // todo: get m
+//  size_t m = 5;
+//  optionalIndices prev_col(m);
+//
+//  // for column j \in 1 to n do
+//  for (Index j = 0; j < n; j++) {
+//    // for row i \in Struct[A*j] do
+//    BOOST_FOREACH(RowIndex i, structA[j]) {
+//      if (prev_col[i]) {
+//        Index k = *(prev_col[i]);
+//        // find root r of the current tree that contains k
+//        Index r = k;
+//        while (parent[r])
+//          r = *parent[r];
+//        if (r != j) parent[r].reset(j);
+//      }
+//      prev_col[i].reset(j);
+//    }
+//  }
+//
+//  return parent;
+//}
+//
+///**
+// * TODO: Build StructA from factor graph
+// */
+//StructA createStructA(const SymbolicFactorGraph& fg) {
+//
+//	StructA structA;
+//
+//	// hardcode for now
+//	list<RowIndex> list0;
+//	list0 += 0, 1;
+//	structA.push_back(list0);
+//	list<RowIndex> list1;
+//	list1 += 0, 2;
+//	structA.push_back(list1);
+//	list<RowIndex> list2;
+//	list2 += 1, 3;
+//	structA.push_back(list2);
+//	list<RowIndex> list3;
+//	list3 += 4;
+//	structA.push_back(list3);
+//	list<RowIndex> list4;
+//	list4 += 2, 3, 4;
+//	structA.push_back(list4);
+//
+//	return structA;
+//}
+//
+///**
+// * Build ETree from factor graph and parent indices
+// */
+//ETree::shared_ptr buildETree(const SymbolicFactorGraph& fg, const optionalIndices& parent) {
+//
+//	// todo: get n
+//	size_t n = 5;
+//
+//	// Create tree structure
+//	vector<ETree::shared_ptr> trees(n);
+//	for (Index k = 1; k <= n; k++) {
+//		Index j = n - k;
+//		trees[j].reset(new ETree(j));
+//		if (parent[j]) trees[*parent[j]]->add(trees[j]);
+//	}
+//
+//	// Hang factors in right places
+//	BOOST_FOREACH(const ETree::sharedFactor& factor, fg)
+//				{
+//					Index j = factor->front();
+//					trees[j]->add(factor);
+//				}
+//
+//	return trees[n - 1];
+//}
+//
+///* ************************************************************************* */
+//// Test of elimination tree creation
+//// graph: f(0,1) f(0,2) f(1,4) f(2,4) f(3,4)
+///* ************************************************************************* */
+///**
+// * Build ETree from factor graph
+// */
+//ETree::shared_ptr buildETree(const SymbolicFactorGraph& fg) {
+//
+//	// create vector of factor indices
+//	StructA structA = createStructA(fg);
+//
+//	// call Gilbert01bit algorithm
+//	optionalIndices parent = buildETree(structA);
+//
+//	// Build ETree from factor graph and parent indices
+//	return buildETree(fg,  parent);
+//}
+//
+//TEST( ETree, buildETree )
+//{
+//	// create example factor graph
+//	SymbolicFactorGraph fg;
+//	fg.push_factor(0, 1);
+//	fg.push_factor(0, 2);
+//	fg.push_factor(1, 4);
+//	fg.push_factor(2, 4);
+//	fg.push_factor(3, 4);
+//
+//	ETree::shared_ptr expected = buildHardcodedTree(fg);
+//
+//	// Build from factor graph
+//	ETree::shared_ptr actual = buildETree(fg);
+//
+//	// todo: CHECK(assert_equal(*expected,*actual));
+//}
+//
+///* ************************************************************************* */
+//// Test to drive elimination tree development
+//// graph: f(0,1) f(0,2) f(1,4) f(2,4) f(3,4)
+///* ************************************************************************* */
+//
+///**
+// * Eliminate factor graph
+// */
+//SymbolicBayesNet eliminate(const SymbolicFactorGraph& fg) {
+//
+//	// build etree
+//	ETree::shared_ptr etree = buildETree(fg);
+//
+//	return etree->eliminate();
+//}
 
-public:
-
-	typedef boost::shared_ptr<Factor> sharedFactor;
-	typedef boost::shared_ptr<ETree> shared_ptr;
-
-private:
-
-	Index key_; /** index associated with root */
-	list<sharedFactor> factors_; /** factors associated with root */
-	list<shared_ptr> subTrees_; /** sub-trees */
-
-	typedef pair<SymbolicBayesNet, Factor> Result;
-
-	/**
-	 * Recursive routine that eliminates the factors arranged in an elimination tree
-	 */
-	Result eliminate_() const {
-
-		SymbolicBayesNet bn;
-
-		set<Index> separator;
-
-		// loop over all factors associated with root
-		// and set-union their keys to a separator
-		BOOST_FOREACH(const sharedFactor& factor, factors_)
-						BOOST_FOREACH(Index key, *factor)
-										if (key != key_) separator.insert(key);
-
-		// for all children, eliminate into Bayes net
-		BOOST_FOREACH(const shared_ptr& child, subTrees_)
-					{
-						Result result = child->eliminate_();
-						bn.push_back(result.first);
-						BOOST_FOREACH(Index key, result.second)
-										if (key != key_) separator.insert(key);
-					}
-
-		// Make the conditional from the key and separator, and insert it in Bayes net
-		vector<Index> parents;
-		std::copy(separator.begin(), separator.end(), back_inserter(parents));
-		Conditional::shared_ptr conditional(new Conditional(key_, parents));
-		bn.push_back(conditional);
-
-		// now create the new factor from separator to return to caller
-		Factor newFactor(separator.begin(), separator.end());
-		return Result(bn, newFactor);
-	}
-
-public:
-
-	/** default constructor */
-	ETree(Index key = 0) :
-		key_(key) {
-	}
-
-	/** add a factor */
-	void add(const sharedFactor& factor) {
-		factors_.push_back(factor);
-	}
-
-	/** add a subtree */
-	void add(const shared_ptr& child) {
-		subTrees_.push_back(child);
-	}
-
-	void print(const std::string& name) const {
-		cout << name << " (" << key_ << ")" << endl;
-		BOOST_FOREACH(const sharedFactor& factor, factors_)
-						factor->print(name + "  ");
-		BOOST_FOREACH(const shared_ptr& child, subTrees_)
-						child->print(name + "  ");
-	}
-
-	bool equals(const ETree& expected, double tol) const {
-		// todo
-		return false;
-	}
-
-	/**
-	 * Eliminate the factors to a Bayes Net
-	 */
-	SymbolicBayesNet eliminate() const {
-
-		// call recursive routine
-		Result result = eliminate_();
-		return result.first;
-	}
-
-};
-
-// build hardcoded tree
-ETree::shared_ptr buildHardcodedTree(const SymbolicFactorGraph& fg) {
-
-	ETree::shared_ptr leaf0(new ETree);
-	leaf0->add(fg[0]);
-	leaf0->add(fg[1]);
-
-	ETree::shared_ptr node1(new ETree(1));
-	node1->add(fg[2]);
-	node1->add(leaf0);
-
-	ETree::shared_ptr node2(new ETree(2));
-	node2->add(fg[3]);
-	node2->add(node1);
-
-	ETree::shared_ptr leaf3(new ETree(3));
-	leaf3->add(fg[4]);
-
-	ETree::shared_ptr etree(new ETree(4));
-	etree->add(leaf3);
-	etree->add(node2);
-
-	return etree;
-}
-
-typedef size_t RowIndex;
-typedef vector<list<RowIndex> > StructA;
-typedef vector<boost::optional<Index> > optionalIndices;
-
-/**
- * Gilbert01bit algorithm in Figure 2.2
- */
-optionalIndices buildETree(const StructA& structA) {
-
-  // todo: get n
-  size_t n = 5;
-  optionalIndices parent(n);
-
-  // todo: get m
-  size_t m = 5;
-  optionalIndices prev_col(m);
-
-  // for column j \in 1 to n do
-  for (Index j = 0; j < n; j++) {
-    // for row i \in Struct[A*j] do
-    BOOST_FOREACH(RowIndex i, structA[j]) {
-      if (prev_col[i]) {
-        Index k = *(prev_col[i]);
-        // find root r of the current tree that contains k
-        Index r = k;
-        while (parent[r])
-          r = *parent[r];
-        if (r != j) parent[r].reset(j);
-      }
-      prev_col[i].reset(j);
-    }
-  }
-
-  return parent;
-}
-
-/**
- * TODO: Build StructA from factor graph
- */
-StructA createStructA(const SymbolicFactorGraph& fg) {
-
-	StructA structA;
-
-	// hardcode for now
-	list<RowIndex> list0;
-	list0 += 0, 1;
-	structA.push_back(list0);
-	list<RowIndex> list1;
-	list1 += 0, 2;
-	structA.push_back(list1);
-	list<RowIndex> list2;
-	list2 += 1, 3;
-	structA.push_back(list2);
-	list<RowIndex> list3;
-	list3 += 4;
-	structA.push_back(list3);
-	list<RowIndex> list4;
-	list4 += 2, 3, 4;
-	structA.push_back(list4);
-
-	return structA;
-}
-
-/**
- * Build ETree from factor graph and parent indices
- */
-ETree::shared_ptr buildETree(const SymbolicFactorGraph& fg, const optionalIndices& parent) {
-
-	// todo: get n
-	size_t n = 5;
-
-	// Create tree structure
-	vector<ETree::shared_ptr> trees(n);
-	for (Index k = 1; k <= n; k++) {
-		Index j = n - k;
-		trees[j].reset(new ETree(j));
-		if (parent[j]) trees[*parent[j]]->add(trees[j]);
-	}
-
-	// Hang factors in right places
-	BOOST_FOREACH(const ETree::sharedFactor& factor, fg)
-				{
-					Index j = factor->front();
-					trees[j]->add(factor);
-				}
-
-	return trees[n - 1];
-}
-
-/* ************************************************************************* */
-// Test of elimination tree creation
-// graph: f(0,1) f(0,2) f(1,4) f(2,4) f(3,4)
-/* ************************************************************************* */
-/**
- * Build ETree from factor graph
- */
-ETree::shared_ptr buildETree(const SymbolicFactorGraph& fg) {
-
-	// create vector of factor indices
-	StructA structA = createStructA(fg);
-
-	// call Gilbert01bit algorithm
-	optionalIndices parent = buildETree(structA);
-
-	// Build ETree from factor graph and parent indices
-	return buildETree(fg,  parent);
-}
-
-TEST( ETree, buildETree )
-{
-	// create example factor graph
-	SymbolicFactorGraph fg;
-	fg.push_factor(0, 1);
-	fg.push_factor(0, 2);
-	fg.push_factor(1, 4);
-	fg.push_factor(2, 4);
-	fg.push_factor(3, 4);
-
-	ETree::shared_ptr expected = buildHardcodedTree(fg);
-
-	// Build from factor graph
-	ETree::shared_ptr actual = buildETree(fg);
-
-	// todo: CHECK(assert_equal(*expected,*actual));
-}
-
-/* ************************************************************************* */
-// Test to drive elimination tree development
-// graph: f(0,1) f(0,2) f(1,4) f(2,4) f(3,4)
-/* ************************************************************************* */
-
-/**
- * Eliminate factor graph
- */
-SymbolicBayesNet eliminate(const SymbolicFactorGraph& fg) {
-
-	// build etree
-	ETree::shared_ptr etree = buildETree(fg);
-
-	return etree->eliminate();
-}
-
-TEST( SymbolicFactorGraph, eliminate )
-{
-	// create expected Chordal bayes Net
-	Conditional::shared_ptr c0(new Conditional(0, 1, 2));
-	Conditional::shared_ptr c1(new Conditional(1, 2, 4));
-	Conditional::shared_ptr c2(new Conditional(2, 4));
-	Conditional::shared_ptr c3(new Conditional(3, 4));
-	Conditional::shared_ptr c4(new Conditional(4));
-
-	SymbolicBayesNet expected;
-	expected.push_back(c3);
-	expected.push_back(c0);
-	expected.push_back(c1);
-	expected.push_back(c2);
-	expected.push_back(c4);
-
-	// Create factor graph
-	SymbolicFactorGraph fg;
-	fg.push_factor(0, 1);
-	fg.push_factor(0, 2);
-	fg.push_factor(1, 4);
-	fg.push_factor(2, 4);
-	fg.push_factor(3, 4);
-
-	// eliminate
-	SymbolicBayesNet actual = eliminate(fg);
-
-	CHECK(assert_equal(expected,actual));
-}
+//TEST( SymbolicFactorGraph, eliminate )
+//{
+//	// create expected Chordal bayes Net
+//	Conditional::shared_ptr c0(new Conditional(0, 1, 2));
+//	Conditional::shared_ptr c1(new Conditional(1, 2, 4));
+//	Conditional::shared_ptr c2(new Conditional(2, 4));
+//	Conditional::shared_ptr c3(new Conditional(3, 4));
+//	Conditional::shared_ptr c4(new Conditional(4));
+//
+//	SymbolicBayesNet expected;
+//	expected.push_back(c3);
+//	expected.push_back(c0);
+//	expected.push_back(c1);
+//	expected.push_back(c2);
+//	expected.push_back(c4);
+//
+//	// Create factor graph
+//	SymbolicFactorGraph fg;
+//	fg.push_factor(0, 1);
+//	fg.push_factor(0, 2);
+//	fg.push_factor(1, 4);
+//	fg.push_factor(2, 4);
+//	fg.push_factor(3, 4);
+//
+//	// eliminate
+//	SymbolicBayesNet actual = eliminate(fg);
+//
+//	CHECK(assert_equal(expected,actual));
+//}
 
 /* ************************************************************************* */
 int main() {
diff --git a/linear/tests/testGaussianFactor.cpp b/linear/tests/testGaussianFactor.cpp
index 065853720..950852283 100644
--- a/linear/tests/testGaussianFactor.cpp
+++ b/linear/tests/testGaussianFactor.cpp
@@ -715,24 +715,24 @@ TEST(GaussianFactor, permuteWithInverse)
   GaussianFactorGraph actualFG; actualFG.push_back(GaussianFactor::shared_ptr(new GaussianFactor(actual)));
   GaussianVariableIndex<> actualIndex(actualFG);
   actual.permuteWithInverse(inversePermutation);
-  actualIndex.permute(*inversePermutation.inverse());
+//  actualIndex.permute(*inversePermutation.inverse());
 
   GaussianFactor expected(0, A3, 2, A2, 4, A1, b, sharedSigma(2, 1.0));
   GaussianFactorGraph expectedFG; expectedFG.push_back(GaussianFactor::shared_ptr(new GaussianFactor(expected)));
-  GaussianVariableIndex<> expectedIndex(expectedFG);
+//  GaussianVariableIndex<> expectedIndex(expectedFG);
 
   CHECK(assert_equal(expected, actual));
 
-  // todo: fix this!!!  VariableIndex should not hold slots
-  for(Index j=0; j<actualIndex.size(); ++j) {
-    BOOST_FOREACH( GaussianVariableIndex<>::mapped_factor_type& factor_pos, actualIndex[j]) {
-      factor_pos.variablePosition = numeric_limits<Index>::max(); }
-  }
-  for(Index j=0; j<expectedIndex.size(); ++j) {
-    BOOST_FOREACH( GaussianVariableIndex<>::mapped_factor_type& factor_pos, expectedIndex[j]) {
-      factor_pos.variablePosition = numeric_limits<Index>::max(); }
-  }
-  CHECK(assert_equal(expectedIndex, actualIndex));
+//  // todo: fix this!!!  VariableIndex should not hold slots
+//  for(Index j=0; j<actualIndex.size(); ++j) {
+//    BOOST_FOREACH( GaussianVariableIndex<>::mapped_factor_type& factor_pos, actualIndex[j]) {
+//      factor_pos.variablePosition = numeric_limits<Index>::max(); }
+//  }
+//  for(Index j=0; j<expectedIndex.size(); ++j) {
+//    BOOST_FOREACH( GaussianVariableIndex<>::mapped_factor_type& factor_pos, expectedIndex[j]) {
+//      factor_pos.variablePosition = numeric_limits<Index>::max(); }
+//  }
+//  CHECK(assert_equal(expectedIndex, actualIndex));
 }
 
 ///* ************************************************************************* */
diff --git a/nonlinear/NonlinearFactorGraph-inl.h b/nonlinear/NonlinearFactorGraph-inl.h
index 2f24c0d1e..6f9b82fe2 100644
--- a/nonlinear/NonlinearFactorGraph-inl.h
+++ b/nonlinear/NonlinearFactorGraph-inl.h
@@ -60,8 +60,7 @@ void NonlinearFactorGraph<Values>::print(const std::string& str) const {
 
   /* ************************************************************************* */
   template<class Values>
-	pair<Ordering::shared_ptr, GaussianVariableIndex<>::shared_ptr>
-  NonlinearFactorGraph<Values>::orderingCOLAMD(const Values& config) const {
+	Ordering::shared_ptr NonlinearFactorGraph<Values>::orderingCOLAMD(const Values& config) const {
 
     // Create symbolic graph and initial (iterator) ordering
 	  FactorGraph<Factor>::shared_ptr symbolic;
@@ -76,14 +75,12 @@ void NonlinearFactorGraph<Values>::print(const std::string& str) const {
 
 	  // Permute the Ordering and VariableIndex with the COLAMD ordering
 	  ordering->permuteWithInverse(*colamdPerm->inverse());
-	  variableIndex.permute(*colamdPerm);
-
-	  // Build a variable dimensions array to upgrade to a GaussianVariableIndex
-	  GaussianVariableIndex<>::shared_ptr gaussianVarIndex(new GaussianVariableIndex<>(variableIndex, config.dims(*ordering)));
+//	  variableIndex.permute(*colamdPerm);
+	  // SL-FIX: fix permutation
 
 	  // Return the Ordering and VariableIndex to be re-used during linearization
 	  // and elimination
-	  return make_pair(ordering, gaussianVarIndex);
+	  return ordering;
 	}
 
   /* ************************************************************************* */
diff --git a/nonlinear/NonlinearFactorGraph.h b/nonlinear/NonlinearFactorGraph.h
index 317ef2af5..72961aac8 100644
--- a/nonlinear/NonlinearFactorGraph.h
+++ b/nonlinear/NonlinearFactorGraph.h
@@ -84,8 +84,7 @@ namespace gtsam {
      * ordering and a VariableIndex, which can later be re-used to save
      * computation.
      */
-		std::pair<Ordering::shared_ptr, GaussianVariableIndex<>::shared_ptr>
-		orderingCOLAMD(const Values& config) const;
+		Ordering::shared_ptr orderingCOLAMD(const Values& config) const;
 
 		/**
 		 * linearize a nonlinear factor graph
diff --git a/nonlinear/NonlinearOptimizer.h b/nonlinear/NonlinearOptimizer.h
index 07a5758aa..89a06ba6e 100644
--- a/nonlinear/NonlinearOptimizer.h
+++ b/nonlinear/NonlinearOptimizer.h
@@ -230,9 +230,7 @@ namespace gtsam {
 				verbosityLevel verbosity = SILENT) {
 
 		  // Use a variable ordering from COLAMD
-		  Ordering::shared_ptr ordering;
-		  GaussianVariableIndex<>::shared_ptr variableIndex;
-		  boost::tie(ordering, variableIndex) = graph->orderingCOLAMD(*config);
+		  Ordering::shared_ptr ordering = graph->orderingCOLAMD(*config);
 
 			double relativeThreshold = 1e-5, absoluteThreshold = 1e-5;
 
@@ -264,9 +262,7 @@ namespace gtsam {
 		 */
 		static shared_values optimizeGN(shared_graph graph, shared_values config,
 				verbosityLevel verbosity = SILENT) {
-      Ordering::shared_ptr ordering;
-      GaussianVariableIndex<>::shared_ptr variableIndex;
-      boost::tie(ordering, variableIndex) = graph->orderingCOLAMD(*config);
+      Ordering::shared_ptr ordering = graph->orderingCOLAMD(*config);
 			double relativeThreshold = 1e-5, absoluteThreshold = 1e-5;
 
 			// initial optimization state is the same in both cases tested
diff --git a/slam/tests/testVSLAMGraph.cpp b/slam/tests/testVSLAMGraph.cpp
index a00bc85d3..a3c973859 100644
--- a/slam/tests/testVSLAMGraph.cpp
+++ b/slam/tests/testVSLAMGraph.cpp
@@ -175,9 +175,7 @@ TEST( Graph, CHECK_ORDERING)
   initialEstimate->insert(3, landmark3);
   initialEstimate->insert(4, landmark4);
 
-  Ordering::shared_ptr ordering;
-  GaussianVariableIndex<>::shared_ptr varindex;
-  boost::tie(ordering,varindex) = graph->orderingCOLAMD(*initialEstimate);
+  Ordering::shared_ptr ordering = graph->orderingCOLAMD(*initialEstimate);
 
   // Create an optimizer and check its error
   // We expect the initial to be zero because config is the ground truth
diff --git a/tests/testGaussianFactorGraph.cpp b/tests/testGaussianFactorGraph.cpp
index 586161962..cfac5fd46 100644
--- a/tests/testGaussianFactorGraph.cpp
+++ b/tests/testGaussianFactorGraph.cpp
@@ -37,7 +37,7 @@ using namespace boost::assign;
 #include <gtsam/inference/SymbolicFactorGraph.h>
 //#include <gtsam/inference/BayesTree-inl.h>
 #include <gtsam/inference/inference-inl.h>
-
+#include <gtsam/inference/EliminationTree-inl.h>
 
 using namespace gtsam;
 using namespace example;
@@ -313,6 +313,9 @@ TEST( GaussianFactorGraph, eliminateAll )
 	GaussianFactorGraph fg1 = createGaussianFactorGraph(ordering);
 	GaussianBayesNet actual = *Inference::Eliminate(fg1);
 	CHECK(assert_equal(expected,actual,tol));
+
+  GaussianBayesNet actualET = *EliminationTree<GaussianFactorGraph>::Create(fg1)->eliminate();
+  CHECK(assert_equal(expected,actualET,tol));
 }
 
 ///* ************************************************************************* */
@@ -488,11 +491,13 @@ TEST( GaussianFactorGraph, optimize )
 
 	// optimize the graph
 	VectorValues actual = optimize(*Inference::Eliminate(fg));
+	VectorValues actualET = optimize(*EliminationTree<GaussianFactorGraph>::Create(fg)->eliminate());
 
 	// verify
 	VectorValues expected = createCorrectDelta(ord);
 
   CHECK(assert_equal(expected,actual));
+  CHECK(assert_equal(expected,actualET));
 }
 
 ///* ************************************************************************* */
@@ -781,10 +786,12 @@ TEST( GaussianFactorGraph, constrained_simple )
 
 	// eliminate and solve
 	VectorValues actual = optimize(*Inference::Eliminate(fg));
+	VectorValues actualET = optimize(*EliminationTree<GaussianFactorGraph>::Create(fg)->eliminate());
 
 	// verify
 	VectorValues expected = createSimpleConstraintValues();
 	CHECK(assert_equal(expected, actual));
+	CHECK(assert_equal(expected, actualET));
 }
 
 /* ************************************************************************* */
diff --git a/tests/testGaussianJunctionTree.cpp b/tests/testGaussianJunctionTree.cpp
index 0644f569b..db5ad1e16 100644
--- a/tests/testGaussianJunctionTree.cpp
+++ b/tests/testGaussianJunctionTree.cpp
@@ -169,7 +169,7 @@ TEST(GaussianJunctionTree, slamlike) {
   ++ i;
 
   // Compare solutions
-  Ordering ordering = *fullgraph.orderingCOLAMD(init).first;
+  Ordering ordering = *fullgraph.orderingCOLAMD(init);
   GaussianFactorGraph linearized = *fullgraph.linearize(init, ordering);
 
   GaussianJunctionTree gjt(linearized);
diff --git a/tests/testNonlinearFactorGraph.cpp b/tests/testNonlinearFactorGraph.cpp
index 6df0f1e92..f91689520 100644
--- a/tests/testNonlinearFactorGraph.cpp
+++ b/tests/testNonlinearFactorGraph.cpp
@@ -62,7 +62,7 @@ TEST( Graph, GET_ORDERING)
 {
   Ordering expected; expected += "x1","l1","x2";
   Graph nlfg = createNonlinearFactorGraph();
-  Ordering actual = *nlfg.orderingCOLAMD(createNoisyValues()).first;
+  Ordering actual = *nlfg.orderingCOLAMD(createNoisyValues());
   CHECK(assert_equal(expected,actual));
 }
 
diff --git a/tests/timeLinearOnDataset.cpp b/tests/timeLinearOnDataset.cpp
index a8931377d..1be19d4d9 100644
--- a/tests/timeLinearOnDataset.cpp
+++ b/tests/timeLinearOnDataset.cpp
@@ -36,7 +36,7 @@ int main(int argc, char *argv[]) {
   pair<shared_ptr<Pose2Graph>, shared_ptr<Pose2Values> > data = load2D(dataset(datasetname));
 
   tic("Z 1 order");
-  Ordering::shared_ptr ordering(data.first->orderingCOLAMD(*data.second).first);
+  Ordering::shared_ptr ordering(data.first->orderingCOLAMD(*data.second));
   toc("Z 1 order");
 
   tic("Z 2 linearize");