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diff --git a/src/expr/emptyset.h b/src/expr/emptyset.h
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+/*********************                                                        */
+/*! \file emptyset.h
+ ** \verbatim
+ ** Original author: Kshitij Bansal
+ ** Major contributors: Morgan Deters
+ ** Minor contributors (to current version): none
+ ** This file is part of the CVC4 project.
+ ** Copyright (c) 2009-2014  New York University and The University of Iowa
+ ** See the file COPYING in the top-level source directory for licensing
+ ** information.\endverbatim
+ **
+ ** \brief [[ Add one-line brief description here ]]
+ **
+ ** [[ Add lengthier description here ]]
+ ** \todo document this file
+ **/
+
+#include "cvc4_public.h"
+
+#pragma once
+
+namespace CVC4 {
+  // messy; Expr needs EmptySet (because it's the payload of a
+  // CONSTANT-kinded expression), and EmptySet needs Expr.
+  class CVC4_PUBLIC EmptySet;
+}/* CVC4 namespace */
+
+#include "expr/expr.h"
+#include "expr/type.h"
+#include <iostream>
+
+namespace CVC4 {
+
+class CVC4_PUBLIC EmptySet {
+
+  const SetType d_type;
+
+  EmptySet() { }
+public:
+
+  /**
+   * Constructs an emptyset of the specified type. Note that the argument
+   * is the type of the set itself, NOT the type of the elements.
+   */
+  EmptySet(SetType setType):d_type(setType) { }
+
+
+  ~EmptySet() throw() {
+  }
+
+  SetType getType() const { return d_type; }
+
+  bool operator==(const EmptySet& es) const throw() {
+    return d_type == es.d_type;
+  }
+  bool operator!=(const EmptySet& es) const throw() {
+    return !(*this == es);
+  }
+
+  bool operator<(const EmptySet& es) const throw() {
+    return d_type < es.d_type;
+  }
+  bool operator<=(const EmptySet& es) const throw() {
+    return d_type <= es.d_type;
+  }
+  bool operator>(const EmptySet& es) const throw() {
+    return !(*this <= es);
+  }
+  bool operator>=(const EmptySet& es) const throw() {
+    return !(*this < es);
+  }
+
+};/* class EmptySet */
+
+std::ostream& operator<<(std::ostream& out, const EmptySet& es) CVC4_PUBLIC;
+
+struct CVC4_PUBLIC EmptySetHashFunction {
+  inline size_t operator()(const EmptySet& es) const {
+    return TypeHashFunction()(es.getType());
+  }
+};/* struct EmptySetHashFunction */
+
+}/* CVC4 namespace */