diff --git a/src/interval/interval.h b/src/interval/interval.h
index 8359dad43..5729bb5a2 100644
--- a/src/interval/interval.h
+++ b/src/interval/interval.h
@@ -107,6 +107,9 @@ public:
     */
     bool contains(interval<T> & b) const;
 
+    bool is_empty() const;
+    void set_empty();
+
     /**
        \brief Return true is the interval contains only one value.
     */
diff --git a/src/interval/interval_def.h b/src/interval/interval_def.h
index b7ae43c56..28fcda1ba 100644
--- a/src/interval/interval_def.h
+++ b/src/interval/interval_def.h
@@ -118,6 +118,19 @@ bool interval<T>::contains(interval<T> & b) const {
     return true;
 }
 
+template<typename T>
+bool interval<T>::is_empty() const {
+    return m_lower == m_upper && m_lower_open && m_upper_open && !m_lower_inf && !m_upper_inf;
+}
+
+template<typename T>
+void interval<T>::set_empty() {
+    numeric_traits<T>::reset(m_lower);
+    numeric_traits<T>::reset(m_upper);
+    m_lower_open = m_upper_open = true;
+    m_lower_inf  = m_upper_inf  = true;
+}
+
 template<typename T>
 bool interval<T>::is_singleton() const {
     return !m_lower_inf && !m_upper_inf && !m_lower_open && !m_upper_open && m_lower == m_upper;