diff --git a/src/include/ranges/index_pack.cc.h b/src/include/ranges/index_pack.cc.h
new file mode 100644
index 0000000..01e4120
--- /dev/null
+++ b/src/include/ranges/index_pack.cc.h
@@ -0,0 +1,61 @@
+
+#ifndef __cxz_index_pack_cc_h__
+#define __cxz_index_pack_cc_h__
+
+#include "index_pack.h"
+
+namespace CNORXZ
+{
+    template <class... Indices>
+    constexpr SPack<Indices...>::SPack(const Sptr<Indices>&... is) :
+	mIs(is...)
+    {}
+    
+    template <class... Indices>
+    constexpr SPack<Indices...>::SPack(const Tuple<Sptr<Indices>...>& is) :
+	mIs(is)
+    {}
+
+    template <class... Indices>
+    constexpr const Tuple<Sptr<Indices>...>& SPack<Indices...>::all() const
+    {
+	return mIs;
+    }
+    
+    template <class... Indices>
+    template <SizeT I>
+    constexpr decltype(auto) SPack<Indices...>::get(std::integral_constant<SizeT,I> i) const
+    {
+	return std::get<I>(mIs);
+    }
+    
+    template <class... Indices>
+    template <SizeT I>
+    constexpr decltype(auto) SPack<Indices...>::operator[](std::integral_constant<SizeT,I> i) const
+    {
+	return get(i);
+    }
+
+    template <class... Indices>
+    template <class Index>
+    constexpr decltype(auto) SPack<Indices...>::rmul(const Sptr<Index>& i) const
+    {
+	return SPack<Indices...,Index>( std::tuple_cat(mIs,i) );
+    }
+
+    template <class... Indices>
+    template <class Index>
+    constexpr decltype(auto) SPack<Indices...>::lmul(const Sptr<Index>& i) const
+    {
+	return SPack<Index,Indices...>( std::tuple_cat(i, mIs) );
+    }
+
+    template <class... Indices>
+    template <class... Indices2>
+    constexpr decltype(auto) SPack<Indices...>::mul(const SPack<Indices2...>& p) const
+    {
+	return SPack<Indices...,Indices2...>( std::tuple_cat(mIs, all()) );
+    }
+}
+
+#endif
diff --git a/src/include/ranges/index_pack.h b/src/include/ranges/index_pack.h
new file mode 100644
index 0000000..95115d6
--- /dev/null
+++ b/src/include/ranges/index_pack.h
@@ -0,0 +1,61 @@
+
+#ifndef __cxz_index_pack_h__
+#define __cxz_index_pack_h__
+
+#include "base/base.h"
+#include "xindex.h"
+
+namespace CNORXZ
+{
+    template <class... Indices>
+    class SPack
+    {
+    public:
+	SP_DEFAULT_MEMBERS(constexpr,SPack);
+	constexpr SPack(const Sptr<Indices>&... is);
+	constexpr SPack(const Tuple<Sptr<Indices>...>& is);
+
+	constexpr const Tuple<Sptr<Indices>...>& all() const;
+
+	constexpr SizeT size() const;
+	
+	template <SizeT I>
+	constexpr decltype(auto) get(std::integral_constant<SizeT,I> i) const;
+
+	template <SizeT I>
+	constexpr decltype(auto) operator[](std::integral_constant<SizeT,I> i) const;
+
+	template <class Index>
+	constexpr decltype(auto) rmul(const Sptr<Index>& i) const;
+
+	template <class Index>
+	constexpr decltype(auto) lmul(const Sptr<Index>& i) const;
+
+	template <class... Indices2>
+	constexpr decltype(auto) mul(const SPack<Indices2...>& p) const;
+	
+    private:
+	Tuple<Sptr<Indices>...> mIs;
+    };
+
+    class DPack
+    {
+    public:
+	DEFAULT_MEMBERS(DPack);
+	DPack(const Vector<XIndexPtr>& is);
+	DPack(Vector<XIndexPtr>&& is);
+
+	const Vector<XIndexPtr>& all() const;
+	SizeT size() const;
+	const XIndexPtr& get(SizeT i) const;
+	const XIndexPtr& operator[](SizeT i) const;
+	DPack rmul(const XIndexPtr& i) const;
+	DPack lmul(const XIndexPtr& i) const;
+	DPack mul(const DPack& p) const;
+	
+    private:
+	Vector<XIndexPtr> mIs;
+    };
+}
+
+#endif
diff --git a/src/include/ranges/mrange.h b/src/include/ranges/mrange.h
index a54cd9b..4120912 100644
--- a/src/include/ranges/mrange.h
+++ b/src/include/ranges/mrange.h
@@ -10,7 +10,8 @@
 
 namespace CNORXZ
 {
-    
+    // template <class FormatT, class... Indices>
+    // -> Format + IndexTuple
     template <class BlockType, class... Indices>
     class GMIndex : public IndexInterface<GMIndex<BlockType,Indices...>,
 					  Tuple<typename Indices::MetaType...> >
@@ -31,6 +32,8 @@ namespace CNORXZ
 	constexpr GMIndex(const GMIndex& i);
 	constexpr GMIndex& operator=(const GMIndex& i);
 
+	//constexpr GMIndex(const SPack<Indices...>& is);
+	//constexpr GMIndex(const FormatT& format, const SPack<Indices...>& is);
 	constexpr GMIndex(const Indices&... is);
 	constexpr GMIndex(const BlockType& blockSizes, const Indices&... is);
 	constexpr GMIndex(const Sptr<Indices>&... is);
@@ -113,7 +116,7 @@ namespace CNORXZ
 	IndexPack mIPack;
 	typedef RemoveRef<decltype(mkLexBlockSizes(mIPack,Isqr<0,NI-1>{}))> LexBlockType;
 	LexBlockType mLexBlockSizes;
-	BlockType mBlockSizes;
+	BlockType mBlockSizes; // -> FormatT
 	SizeT mLex;
 	typedef RemoveRef<decltype(mkLMax(mIPack))> LMaxT;
 	LMaxT mLMax;
diff --git a/src/include/ranges/ranges.cc.h b/src/include/ranges/ranges.cc.h
index a72925b..59de5f9 100644
--- a/src/include/ranges/ranges.cc.h
+++ b/src/include/ranges/ranges.cc.h
@@ -8,3 +8,4 @@
 #include "dindex.cc.h"
 #include "lindex.cc.h"
 #include "index_mul.cc.h"
+#include "index_pack.cc.h"
diff --git a/src/include/ranges/ranges.h b/src/include/ranges/ranges.h
index d58a141..801ad48 100644
--- a/src/include/ranges/ranges.h
+++ b/src/include/ranges/ranges.h
@@ -10,5 +10,6 @@
 #include "dindex.h"
 #include "lindex.h"
 #include "index_mul.h"
+#include "index_pack.h"
 
 #include "ranges.cc.h"
diff --git a/src/lib/CMakeLists.txt b/src/lib/CMakeLists.txt
index 743b83a..0d469b1 100644
--- a/src/lib/CMakeLists.txt
+++ b/src/lib/CMakeLists.txt
@@ -6,6 +6,7 @@ set(libcnorxz_a_SOURCES
   ${CMAKE_SOURCE_DIR}/src/lib/ranges/yrange.cc
   ${CMAKE_SOURCE_DIR}/src/lib/ranges/crange.cc
   ${CMAKE_SOURCE_DIR}/src/lib/ranges/dindex.cc
+  ${CMAKE_SOURCE_DIR}/src/lib/ranges/index_pack.cc
   )
 
 add_library(cnorxz_obj OBJECT
diff --git a/src/lib/ranges/index_pack.cc b/src/lib/ranges/index_pack.cc
new file mode 100644
index 0000000..9be8479
--- /dev/null
+++ b/src/lib/ranges/index_pack.cc
@@ -0,0 +1,59 @@
+
+#include "ranges/index_pack.h"
+
+namespace CNORXZ
+{
+    DPack::DPack(const Vector<XIndexPtr>& is) :
+	mIs(is)
+    {}
+
+    DPack::DPack(Vector<XIndexPtr>&& is) :
+	mIs(std::forward<Vector<XIndexPtr>>(is))
+    {}
+
+    const Vector<XIndexPtr>& DPack::all() const
+    {
+	return mIs;
+    }
+    
+    SizeT DPack::size() const
+    {
+	return mIs.size();
+    }
+
+    const XIndexPtr& DPack::get(SizeT i) const
+    {
+	return mIs[i];
+    }
+    
+    const XIndexPtr& DPack::operator[](SizeT i) const
+    {
+	return get(i);
+    }
+    
+    DPack DPack::rmul(const XIndexPtr& i) const
+    {
+	auto o = mIs;
+	o.push_back(i);
+	return DPack(std::move(o));
+    }
+    
+    DPack DPack::lmul(const XIndexPtr& i) const
+    {
+	Vector<XIndexPtr> o;
+	o.reserve(size()+1);
+	o.push_back(i);
+	o.insert(o.end(), mIs.begin(), mIs.end());
+	return DPack(std::move(o));
+    }
+    
+    DPack DPack::mul(const DPack& p) const
+    {
+	Vector<XIndexPtr> o;
+	o.reserve(size()+p.size());
+	o.insert(o.end(), mIs.begin(), mIs.end());
+	o.insert(o.end(), p.all().begin(), p.all().end());
+	return DPack(std::move(o));
+    }
+
+}