diff --git a/include/boost/ratio/detail/mpl/abs.hpp b/include/boost/ratio/detail/mpl/abs.hpp
new file mode 100644
index 0000000..8d6ef48
--- /dev/null
+++ b/include/boost/ratio/detail/mpl/abs.hpp
@@ -0,0 +1,79 @@
+////////////////////////////////////////////////////////////////////
+//
+// Copyright Vicente J. Botet Escriba 2010
+//
+// Distributed under the Boost Software License, Version 1.0. 
+// (See accompanying file LICENSE_1_0.txt or copy at 
+// http://www.boost.org/LICENSE_1_0.txt)
+//
+// See http://www.boost.org/libs/mpl for documentation.
+//
+////////////////////////////////////////////////////////////////////
+#ifndef BOOST_MPL_ABS_HPP_INCLUDED
+#define BOOST_MPL_ABS_HPP_INCLUDED
+
+#include <boost/mpl/integral_c.hpp>
+#include <boost/mpl/aux_/na_spec.hpp>
+#include <boost/mpl/aux_/lambda_support.hpp>
+#include <boost/mpl/aux_/config/eti.hpp>
+#include <boost/mpl/aux_/config/integral.hpp>
+#include <boost/mpl/aux_/config/static_constant.hpp>
+
+namespace boost { namespace mpl {
+
+template< typename Tag > struct abs_impl;
+
+template< typename T > struct abs_tag
+{
+    typedef typename T::tag type;
+};
+
+template<
+      typename BOOST_MPL_AUX_NA_PARAM(N)
+    >
+struct abs
+    : abs_impl<
+          typename abs_tag<N>::type
+        >::template apply<N>::type
+{
+    BOOST_MPL_AUX_LAMBDA_SUPPORT(1, abs, (N))
+};
+
+BOOST_MPL_AUX_NA_SPEC(1, abs)
+
+template<
+      typename T
+    , T n1
+    >
+struct abs_c
+    : abs<integral_c<T,n1> >
+{
+};
+
+#if defined(BOOST_MPL_CFG_NO_NESTED_VALUE_ARITHMETIC_2)
+namespace aux {
+template< typename T, T n > struct abs_wknd
+{
+    BOOST_STATIC_CONSTANT(T, value = (n < 0 ? -n : n));
+    typedef integral_c<T,value> type;
+};
+}
+#endif
+
+template<>
+struct abs_impl<integral_c_tag>
+{
+#if defined(BOOST_MPL_CFG_NO_NESTED_VALUE_ARITHMETIC_2)
+    template< typename N > struct apply
+        : aux::abs_wknd< typename N::value_type, N::value >
+#else
+    template< typename N > struct apply
+        : integral_c< typename N::value_type, ((N::value < 0) ? (-N::value) : N::value ) >
+#endif    
+    {
+    };
+};
+
+}}
+
+#endif // BOOST_MPL_ABS_HPP_INCLUDED
diff --git a/include/boost/ratio/detail/mpl/gcd.hpp b/include/boost/ratio/detail/mpl/gcd.hpp
new file mode 100644
index 0000000..22d5e2f
--- /dev/null
+++ b/include/boost/ratio/detail/mpl/gcd.hpp
@@ -0,0 +1,89 @@
+////////////////////////////////////////////////////////////////////
+//
+// Copyright Vicente J. Botet Escriba 2010
+//
+// Distributed under the Boost Software License, Version 1.0. 
+// (See accompanying file LICENSE_1_0.txt or copy at 
+// http://www.boost.org/LICENSE_1_0.txt)
+//
+// See http://www.boost.org/libs/mpl for documentation.
+//
+////////////////////////////////////////////////////////////////////
+#ifndef BOOST_MPL_GCD_HPP_INCLUDED
+#define BOOST_MPL_GCD_HPP_INCLUDED
+
+#include <boost/mpl/integral_c.hpp>
+#include <boost/mpl/abs.hpp>
+#include <boost/mpl/aux_/largest_int.hpp>
+#include <boost/mpl/aux_/na_spec.hpp>
+#include <boost/mpl/aux_/lambda_support.hpp>
+#include <boost/mpl/aux_/config/eti.hpp>
+#include <boost/mpl/aux_/config/integral.hpp>
+#include <boost/mpl/aux_/config/static_constant.hpp>
+
+namespace boost { namespace mpl {
+
+template< typename Tag1, typename Tag2 > struct gcd_impl;
+
+template< typename T > struct gcd_tag
+{
+    typedef typename T::tag type;
+};
+
+template<
+      typename BOOST_MPL_AUX_NA_PARAM(N1)
+    , typename BOOST_MPL_AUX_NA_PARAM(N2)
+    >
+struct gcd
+    : gcd_impl<
+          typename gcd_tag<N1>::type
+        , typename gcd_tag<N2>::type
+        >::template apply<N1, N2>::type
+{
+    BOOST_MPL_AUX_LAMBDA_SUPPORT(2, gcd, (N1, N2))
+};
+
+BOOST_MPL_AUX_NA_SPEC(2, gcd)
+
+template<
+      typename T
+    , T n1
+    , T n2
+    >
+struct gcd_c
+    : gcd<integral_c<T,n1>,integral_c<T,n2> >
+{
+};
+
+namespace aux {
+    template< typename T1, T1 n1, bool n1_is_0, typename T2, T2 n2, bool n2_is_0 > 
+    struct gcd_aux
+ 
+        : gcd_aux<T2, n2, n2==0, 
+                    typename aux::largest_int<T1, T2>::type,
+                    //~ T1, 
+                    (n1 % n2), (n1 % n2)==0>
+    {};
+    
+    template <typename T1, T1 n1, typename T2, T2 n2>
+    struct gcd_aux<T1, n1, false, T2, n2, true> : integral_c<T1, n1> 
+    {};
+
+    template <typename T1, T1 n1, typename T2, T2 n2, bool C>
+    struct gcd_aux<T1, n1, true, T2, n2, C> : integral_c<T2, n2> 
+    {};
+}
+
+template<>
+struct gcd_impl<integral_c_tag, integral_c_tag>
+{
+    template< typename N1, typename N2 > struct apply
+        : abs<aux::gcd_aux< typename N1::value_type, N1::value, N1::value==0, 
+                        typename N2::value_type, N2::value, N2::value==0  > >
+    {
+    };
+};
+
+}}
+
+#endif // BOOST_MPL_GCD_HPP_INCLUDED
diff --git a/include/boost/ratio/detail/mpl/lcm.hpp b/include/boost/ratio/detail/mpl/lcm.hpp
new file mode 100644
index 0000000..80d3b98
--- /dev/null
+++ b/include/boost/ratio/detail/mpl/lcm.hpp
@@ -0,0 +1,89 @@
+////////////////////////////////////////////////////////////////////
+//
+// Copyright Vicente J. Botet Escriba 2010
+//
+// Distributed under the Boost Software License, Version 1.0. 
+// (See accompanying file LICENSE_1_0.txt or copy at 
+// http://www.boost.org/LICENSE_1_0.txt)
+//
+// See http://www.boost.org/libs/mpl for documentation.
+//
+////////////////////////////////////////////////////////////////////
+#ifndef BOOST_MPL_LCM_HPP_INCLUDED
+#define BOOST_MPL_LCM_HPP_INCLUDED
+
+#include <boost/mpl/integral_c.hpp>
+#include <boost/mpl/abs.hpp>
+#include <boost/mpl/aux_/largest_int.hpp>
+#include <boost/mpl/aux_/na_spec.hpp>
+#include <boost/mpl/aux_/lambda_support.hpp>
+#include <boost/mpl/aux_/config/eti.hpp>
+#include <boost/mpl/aux_/config/integral.hpp>
+#include <boost/mpl/aux_/config/static_constant.hpp>
+
+namespace boost { namespace mpl {
+
+template< typename Tag1, typename Tag2 > struct lcm_impl;
+
+template< typename T > struct lcm_tag
+{
+    typedef typename T::tag type;
+};
+
+template<
+      typename BOOST_MPL_AUX_NA_PARAM(N1)
+    , typename BOOST_MPL_AUX_NA_PARAM(N2)
+    >
+struct lcm
+    : lcm_impl<
+          typename lcm_tag<N1>::type
+        , typename lcm_tag<N2>::type
+        >::template apply<N1, N2>::type
+{
+    BOOST_MPL_AUX_LAMBDA_SUPPORT(2, lcm, (N1, N2))
+};
+
+BOOST_MPL_AUX_NA_SPEC(2, lcm)
+
+template<
+      typename T
+    , T n1
+    , T n2
+    >
+struct lcm_c
+    : lcm<integral_c<T,n1>,integral_c<T,n2> >
+{
+};
+
+
+namespace aux {
+    template< typename T1, T1 n1, bool n1_is_0, typename T2, T2 n2, bool n2_is_0 > 
+    struct lcm_aux
+ 
+        : abs<integral_c< typename aux::largest_int<T1, T2>::type,
+            ( n1 / gcd<integral_c<T1,n1>, integral_c<T2,n2> >::value * n2 )  
+        > >
+    {};
+    
+    template <typename T1, T1 n1, typename T2, T2 n2>
+    struct lcm_aux<T1, n1, false, T2, n2, true> : integral_c<T2, 0> 
+    {};
+
+    template <typename T1, T1 n1, typename T2, T2 n2, bool C>
+    struct lcm_aux<T1, n1, true, T2, n2, C> : integral_c<T1, 0> 
+    {};
+}
+
+template<>
+struct lcm_impl<integral_c_tag, integral_c_tag>
+{
+    template< typename N1, typename N2 > struct apply
+        : abs<aux::lcm_aux< typename N1::value_type, N1::value, N1::value==0, 
+                        typename N2::value_type, N2::value, N2::value==0  > >
+    {
+    };
+};
+
+}}
+
+#endif // BOOST_MPL_LCM_HPP_INCLUDED
diff --git a/include/boost/ratio/detail/mpl/sign.hpp b/include/boost/ratio/detail/mpl/sign.hpp
new file mode 100644
index 0000000..31ef57b
--- /dev/null
+++ b/include/boost/ratio/detail/mpl/sign.hpp
@@ -0,0 +1,79 @@
+////////////////////////////////////////////////////////////////////
+//
+// Copyright Vicente J. Botet Escriba 2010
+//
+// Distributed under the Boost Software License, Version 1.0. 
+// (See accompanying file LICENSE_1_0.txt or copy at 
+// http://www.boost.org/LICENSE_1_0.txt)
+//
+// See http://www.boost.org/libs/mpl for documentation.
+//
+////////////////////////////////////////////////////////////////////
+#ifndef BOOST_MPL_SIGN_HPP_INCLUDED
+#define BOOST_MPL_SIGN_HPP_INCLUDED
+
+#include <boost/mpl/integral_c.hpp>
+#include <boost/mpl/aux_/na_spec.hpp>
+#include <boost/mpl/aux_/lambda_support.hpp>
+#include <boost/mpl/aux_/config/eti.hpp>
+#include <boost/mpl/aux_/config/integral.hpp>
+#include <boost/mpl/aux_/config/static_constant.hpp>
+
+namespace boost { namespace mpl {
+
+template< typename Tag > struct sign_impl;
+
+template< typename T > struct sign_tag
+{
+    typedef typename T::tag type;
+};
+
+template<
+      typename BOOST_MPL_AUX_NA_PARAM(N)
+    >
+struct sign
+    : sign_impl<
+          typename sign_tag<N>::type
+        >::template apply<N>::type
+{
+    BOOST_MPL_AUX_LAMBDA_SUPPORT(1, sign, (N))
+};
+
+BOOST_MPL_AUX_NA_SPEC(1, sign)
+
+template<
+      typename T
+    , T n1
+    >
+struct sign_c
+    : sign<integral_c<T,n1> >
+{
+};
+
+#if defined(BOOST_MPL_CFG_NO_NESTED_VALUE_ARITHMETIC_2)
+namespace aux {
+template< typename T, T n > struct sign_wknd
+{
+    BOOST_STATIC_CONSTANT(T, value = (n == 0 ? 0 : (n < 0 ? -1 : 1)));
+    typedef integral_c<T,value> type;
+};
+}
+#endif
+
+template<>
+struct sign_impl<integral_c_tag>
+{
+#if defined(BOOST_MPL_CFG_NO_NESTED_VALUE_ARITHMETIC_2)
+    template< typename N > struct apply
+        : aux::sign_wknd< typename N::value_type, N::value >
+#else
+    template< typename N > struct apply
+        : integral_c< typename N::value_type, (N::value == 0 ? 0 : (N::value < 0 ? -1 : 1)) >
+#endif    
+    {
+    };
+};
+
+}}
+
+#endif // BOOST_MPL_SIGN_HPP_INCLUDED
diff --git a/include/boost/ratio/detail/overflow_helpers.hpp b/include/boost/ratio/detail/overflow_helpers.hpp
index fcac882..6e3fc94 100644
--- a/include/boost/ratio/detail/overflow_helpers.hpp
+++ b/include/boost/ratio/detail/overflow_helpers.hpp
@@ -32,14 +32,8 @@ time2_demo contained this comment:
 #ifndef BOOST_RATIO_DETAIL_RATIO_OPERATIONS_HPP
 #define BOOST_RATIO_DETAIL_RATIO_OPERATIONS_HPP
 
-//~ #include <boost/static_integer/static_abs.hpp>
-//~ #include <boost/static_integer/static_sign.hpp>
-//~ #include <boost/static_integer/static_lcm.hpp>
-//~ #include <boost/static_integer/static_gcd.hpp>
-#include <boost/mpl/abs.hpp>
-#include <boost/mpl/sign.hpp>
-//~ #include <boost/mpl/gcd.hpp>
-//~ #include <boost/mpl/lcm.hpp>
+#include <boost/ratio/detail/mpl/abs.hpp>
+#include <boost/ratio/detail/mpl/sign.hpp>
 #include <cstdlib>
 #include <climits>
 #include <limits>
diff --git a/include/boost/ratio/ratio.hpp b/include/boost/ratio/ratio.hpp
index 7c92738..3d198a2 100644
--- a/include/boost/ratio/ratio.hpp
+++ b/include/boost/ratio/ratio.hpp
@@ -33,10 +33,10 @@ time2_demo contained this comment:
 #define BOOST_RATIO_RATIO_HPP
 
 #include <boost/config.hpp>
-#include <boost/mpl/abs.hpp>
-#include <boost/mpl/sign.hpp>
-#include <boost/mpl/gcd.hpp>
-#include <boost/mpl/lcm.hpp>
+#include <boost/ratio/detail/mpl/abs.hpp>
+#include <boost/ratio/detail/mpl/sign.hpp>
+#include <boost/ratio/detail/mpl/gcd.hpp>
+#include <boost/ratio/detail/mpl/lcm.hpp>
 #include <cstdlib>
 #include <climits>
 #include <limits>