diff --git a/lemon/bits/invalid.h b/lemon/bits/invalid.h
deleted file mode 100644
--- a/lemon/bits/invalid.h
+++ /dev/null
@@ -1,55 +0,0 @@
-/* -*- mode: C++; indent-tabs-mode: nil; -*-
- *
- * This file is a part of LEMON, a generic C++ optimization library.
- *
- * Copyright (C) 2003-2008
- * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
- * (Egervary Research Group on Combinatorial Optimization, EGRES).
- *
- * Permission to use, modify and distribute this software is granted
- * provided that this copyright notice appears in all copies. For
- * precise terms see the accompanying LICENSE file.
- *
- * This software is provided "AS IS" with no warranty of any kind,
- * express or implied, and with no claim as to its suitability for any
- * purpose.
- *
- */
-
-#ifndef LEMON_BITS_INVALID_H
-#define LEMON_BITS_INVALID_H
-
-///\file
-///\brief Definition of INVALID.
-
-namespace lemon {
-
-  /// \brief Dummy type to make it easier to create invalid iterators.
-  ///
-  /// Dummy type to make it easier to create invalid iterators.
-  /// See \ref INVALID for the usage.
-  struct Invalid {
-  public:
-    bool operator==(Invalid) { return true;  }
-    bool operator!=(Invalid) { return false; }
-    bool operator< (Invalid) { return false; }
-  };
-
-  /// \brief Invalid iterators.
-  ///
-  /// \ref Invalid is a global type that converts to each iterator
-  /// in such a way that the value of the target iterator will be invalid.
-
-  //Some people didn't like this:
-  //const Invalid &INVALID = *(Invalid *)0;
-
-#ifdef LEMON_ONLY_TEMPLATES
-  const Invalid INVALID = Invalid();
-#else
-  extern const Invalid INVALID;
-#endif
-
-} //namespace lemon
-
-#endif
-