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diff --git a/moses/src/HypothesisStackNormal.h b/moses/src/HypothesisStackNormal.h
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+// $Id: HypothesisStackNormal.h 2451 2009-08-04 13:46:24Z hieuhoang1972 $
+
+/***********************************************************************
+Moses - factored phrase-based language decoder
+Copyright (C) 2006 University of Edinburgh
+
+This library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Lesser General Public
+License as published by the Free Software Foundation; either
+version 2.1 of the License, or (at your option) any later version.
+
+This library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public
+License along with this library; if not, write to the Free Software
+Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+***********************************************************************/
+
+#pragma once
+
+#include <limits>
+#include <set>
+#include "Hypothesis.h"
+#include "HypothesisStack.h"
+#include "WordsBitmap.h"
+
+namespace Moses
+{
+	// class WordsBitmap;
+	// typedef size_t WordsBitmapID;
+
+/** Stack for instances of Hypothesis, includes functions for pruning. */ 
+class HypothesisStackNormal: public HypothesisStack
+{
+public:
+	friend std::ostream& operator<<(std::ostream&, const HypothesisStackNormal&);
+
+protected:
+	float m_bestScore; /**< score of the best hypothesis in collection */
+	float m_worstScore; /**< score of the worse hypothesis in collection */
+	map< WordsBitmapID, float > m_diversityWorstScore; /**< score of worst hypothesis for particular source word coverage */
+	float m_beamWidth; /**< minimum score due to threashold pruning */
+	size_t m_maxHypoStackSize; /**< maximum number of hypothesis allowed in this stack */
+	size_t m_minHypoStackDiversity; /**< minimum number of hypothesis with different source word coverage */
+	bool m_nBestIsEnabled; /**< flag to determine whether to keep track of old arcs */
+
+	/** add hypothesis to stack. Prune if necessary. 
+	 * Returns false if equiv hypo exists in collection, otherwise returns true
+	 */
+	std::pair<HypothesisStackNormal::iterator, bool> Add(Hypothesis *hypothesis);
+
+	/** destroy all instances of Hypothesis in this collection */
+	void RemoveAll();
+
+	void SetWorstScoreForBitmap( WordsBitmapID id, float worstScore ) {
+		m_diversityWorstScore[ id ] = worstScore;
+	}
+
+public:
+	float GetWorstScoreForBitmap( WordsBitmapID id ) {
+		if (m_diversityWorstScore.find( id ) == m_diversityWorstScore.end())
+			return -numeric_limits<float>::infinity();
+		return m_diversityWorstScore[ id ];
+	}
+	float GetWorstScoreForBitmap( const WordsBitmap &coverage ) {
+		return GetWorstScoreForBitmap( coverage.GetID() );
+	}
+
+	HypothesisStackNormal();
+
+	/** adds the hypo, but only if within thresholds (beamThr, stackSize).
+	*	This function will recombine hypotheses silently!  There is no record
+	* (could affect n-best list generation...TODO)
+	* Call stack for adding hypothesis is
+			AddPrune()
+				Add()
+					AddNoPrune()
+	*/
+	bool AddPrune(Hypothesis *hypothesis);
+
+	/** set maximum number of hypotheses in the collection
+	 * \param maxHypoStackSize maximum number (typical number: 100)
+	 * \param maxHypoStackSize maximum number (defauly: 0)
+	 */
+	inline void SetMaxHypoStackSize(size_t maxHypoStackSize, size_t minHypoStackDiversity)
+	{
+		m_maxHypoStackSize = maxHypoStackSize;
+		m_minHypoStackDiversity = minHypoStackDiversity;
+	}
+
+	/** set beam threshold, hypotheses in the stack must not be worse than 
+	 * this factor times the best score to be allowed in the stack
+	 * \param beamThreshold minimum factor (typical number: 0.03)
+	 */
+	inline void SetBeamWidth(float beamWidth)
+	{
+		m_beamWidth = beamWidth;
+	}
+	/** return score of the best hypothesis in the stack */
+	inline float GetBestScore() const
+	{
+		return m_bestScore;
+	}
+	/** return worst allowable score */
+	inline float GetWorstScore() const
+	{
+		return m_worstScore;
+	}
+	
+	/** pruning, if too large.
+	 * Pruning algorithm: find a threshold and delete all hypothesis below it.
+	 * The threshold is chosen so that exactly newSize top items remain on the 
+	 * stack in fact, in situations where some of the hypothesis fell below 
+	 * m_beamWidth, the stack will contain less items.
+	 * \param newSize maximum size */
+	void PruneToSize(size_t newSize);
+
+	//! return the hypothesis with best score. Used to get the translated at end of decoding
+	const Hypothesis *GetBestHypothesis() const;
+	//! return all hypothesis, sorted by descending score. Used in creation of N best list
+	std::vector<const Hypothesis*> GetSortedList() const;
+	std::vector<Hypothesis*> GetSortedListNOTCONST();
+	
+	/** make all arcs in point to the equiv hypothesis that contains them. 
+	* Ie update doubly linked list be hypo & arcs
+	*/
+	void CleanupArcList();
+	
+	TO_STRING();
+};
+
+}