diff --git a/src/index_base.h b/src/index_base.h
index 41e644d..680c298 100644
--- a/src/index_base.h
+++ b/src/index_base.h
@@ -45,11 +45,7 @@ namespace MultiArrayTools
 	virtual void linkTo(IndefinitIndexBase* target) = 0; 
 	virtual IndefinitIndexBase* getLinked(const std::string& name) = 0;
 
-	// include sub-index update routine
 	virtual void setPos(size_t pos);
-
-	// does NOT include sub-index update routine !!
-	// relative position to current
 	virtual void setPosRel(int relPos);
 
 	virtual size_t max() const = 0;
diff --git a/src/multi_array.h b/src/multi_array.h
index 81dac14..6631971 100644
--- a/src/multi_array.h
+++ b/src/multi_array.h
@@ -24,6 +24,8 @@ namespace MultiArrayTools
 	
 	DEFAULT_MEMBERS(MultiArrayBase);
 	MultiArrayBase(const Range& range);
+
+	virtual ~MultiArrayBase() = default;
 	
 	virtual T& operator[](const typename Range::IndexType& i) = 0;
 	virtual const T& operator[](const typename Range::IndexType& i) const = 0;
diff --git a/src/multi_array_header.h b/src/multi_array_header.h
index 8bb14cf..bcac116 100644
--- a/src/multi_array_header.h
+++ b/src/multi_array_header.h
@@ -42,6 +42,7 @@ namespace MultiArrayTools
     typedef SingleRange<size_t, RangeType::ENSEMBLE> EnsR;
     typedef MultiRange<Space1dNR,Space1dNR,Space1dNR> Space3dNR;
     typedef MultiRange<Mom1dNR,Mom1dNR,Mom1dNR> Mom3dNR;
+    typedef SingleRange<VET, RangeType::VALUE_ERROR> ValErrR;
     // ...
     
 }
diff --git a/src/multi_range.cc b/src/multi_range.cc
index 3bb4a0e..cc1ceac 100644
--- a/src/multi_range.cc
+++ b/src/multi_range.cc
@@ -612,6 +612,34 @@ namespace MultiArrayTools
 	    return 0;
 	}
     }
+
+    template <size_t N>
+    struct MetaTypePrinter
+    {
+	template <class... Indices>
+	static void print(std::ostream& os, typename MultiIndex<Indices...>::MetaType& meta)
+	{
+	    MetaTypePrinter<N-1>::print(os, meta);
+	    os << std::get<N>(meta) << '\t';
+	}
+    };
+
+    template <>
+    struct MetaTypePrinter<0>
+    {
+	template <class... Indices>
+	static void print(std::ostream& os, typename MultiIndex<Indices...>::MetaType& meta)
+	{
+	    os << std::get<0>(meta) << '\t';
+	}
+    };
+    
+    template <class... Indices>
+    std::ostream& operator<<(std::ostream& os, typename MultiIndex<Indices...>::MetaType& meta)
+    {
+	MetaTypePrinter<sizeof...(Indices)-1>::print(os, meta);
+	return os;
+    }
     
     /******************
      *   MultiRange   *
diff --git a/src/multi_range.h b/src/multi_range.h
index 82f2ab5..722d88b 100644
--- a/src/multi_range.h
+++ b/src/multi_range.h
@@ -92,6 +92,9 @@ namespace MultiArrayTools
 	//virtual void assignRange(RangeBase<MultiIndex<Indices...> > const* range) override;
     };
 
+    template <class... Indices>
+    std::ostream& operator<<(std::ostream& os, typename MultiIndex<Indices...>::MetaType& meta);
+    
     /*****************************
      *   IndexGetter Functions   *
      ****************************/
diff --git a/src/name.cc b/src/name.cc
index 8ba778d..2f3d710 100644
--- a/src/name.cc
+++ b/src/name.cc
@@ -66,5 +66,18 @@ namespace MultiArrayTools
     {
 	return mSub.size();
     }
+
+    std::ostream& operator<<(std::ostream& os, const Name& name)
+    {
+	if(name.size() != 0){
+	    for(size_t i = 0; i != name.size(); ++i){
+		os << name.get(i) << '\t';
+	    }
+	}
+	else {
+	    os << name.own();
+	}
+	return os;
+    }
     
 }
diff --git a/src/name.h b/src/name.h
index c3eb9ce..0e466de 100644
--- a/src/name.h
+++ b/src/name.h
@@ -5,6 +5,7 @@
 
 #include <cstdlib>
 #include <string>
+#include <ostream>
 
 #include "base_def.h"
 
@@ -33,6 +34,8 @@ namespace MultiArrayTools
 	std::vector<Name> mSub;	
     };
 
+    std::ostream& operator<<(std::ostream& os, const Name& name);
+    
 }
 
 #include "name.cc"
diff --git a/src/range_base.h b/src/range_base.h
index e93d13c..a96c88d 100644
--- a/src/range_base.h
+++ b/src/range_base.h
@@ -20,7 +20,8 @@ namespace MultiArrayTools
 	MOMENTUM = 3,
 	LORENTZ = 4,
 	SPIN = 5,
-	ENSEMBLE = 6
+	ENSEMBLE = 6,
+	VALUE_ERROR = 7
     };
 
     class MultiRangeType
@@ -58,6 +59,8 @@ namespace MultiArrayTools
     {
     public:
 	typedef Index IndexType;
+
+	virtual ~RangeBase() = default;
 	
 	virtual size_t size() const = 0;
 	virtual Index begin() const = 0;
diff --git a/src/single_range.cc b/src/single_range.cc
index 6400c5b..779e97c 100644
--- a/src/single_range.cc
+++ b/src/single_range.cc
@@ -53,6 +53,168 @@ namespace MultiArrayTools
     {
 	return SingleIndex<U,TYPE>(this, mSpace.size());
     }
+
+    // specializations
+
+    SingleRange<int,RangeType::SPACE>::SingleRange(int begin, int end) :
+	RangeBase<SingleIndex<int,RangeType::SPACE> >(),
+	mBegin(begin), mEnd(end) {}
+    
+    int SingleRange<int,RangeType::SPACE>::get(size_t pos) const
+    {
+	return mBegin + pos;
+    }
+
+    size_t SingleRange<int,RangeType::SPACE>::getMeta(int metaPos) const
+    {
+	return metaPos - mBegin;
+    }
+
+    
+    size_t SingleRange<int,RangeType::SPACE>::size() const
+    {
+	return mEnd - mBegin;
+    }
+
+    
+    MultiRangeType SingleRange<int,RangeType::SPACE>::type() const
+    {
+	return MultiRangeType(RangeType::SPACE);
+    }
+    
+    
+    SingleIndex<int,RangeType::SPACE> SingleRange<int,RangeType::SPACE>::begin() const
+    {
+	return SingleIndex<int,RangeType::SPACE>(this, 0);
+    }
+
+    
+    SingleIndex<int,RangeType::SPACE> SingleRange<int,RangeType::SPACE>::end() const
+    {
+	return SingleIndex<int,RangeType::SPACE>(this, size());
+    }
+
+    // 
+    
+    
+    SingleRange<size_t,RangeType::ENSEMBLE>::SingleRange(size_t num) :
+	RangeBase<SingleIndex<size_t,RangeType::ENSEMBLE> >(),
+	mNum(num) {}
+    
+    
+    size_t SingleRange<size_t,RangeType::ENSEMBLE>::get(size_t pos) const
+    {
+	return pos;
+    }
+
+    
+    size_t SingleRange<size_t,RangeType::ENSEMBLE>::getMeta(size_t metaPos) const
+    {
+	return metaPos;
+    }
+
+    
+    size_t SingleRange<size_t,RangeType::ENSEMBLE>::size() const
+    {
+	return mNum;
+    }
+
+    
+    MultiRangeType SingleRange<size_t,RangeType::ENSEMBLE>::type() const
+    {
+	return MultiRangeType(RangeType::ENSEMBLE);
+    }
+    
+    
+    SingleIndex<size_t,RangeType::ENSEMBLE> SingleRange<size_t,RangeType::ENSEMBLE>::begin() const
+    {
+	return SingleIndex<size_t,RangeType::ENSEMBLE>(this, 0);
+    }
+
+    
+    SingleIndex<size_t,RangeType::ENSEMBLE> SingleRange<size_t,RangeType::ENSEMBLE>::end() const
+    {
+	return SingleIndex<size_t,RangeType::ENSEMBLE>(this, size());
+    }
+
+    //
+    
+    VET SingleRange<VET,RangeType::VALUE_ERROR>::get(size_t pos) const
+    {
+	return static_cast<VET>( pos );
+    }
+
+    
+    size_t SingleRange<VET,RangeType::VALUE_ERROR>::getMeta(VET metaPos) const
+    {
+	return static_cast<size_t>( metaPos );
+    }
+
+    
+    size_t SingleRange<VET,RangeType::VALUE_ERROR>::size() const
+    {
+	return 2;
+    }
+
+    
+    MultiRangeType SingleRange<VET,RangeType::VALUE_ERROR>::type() const
+    {
+	return MultiRangeType(RangeType::VALUE_ERROR);
+    }
+    
+    
+    SingleIndex<VET,RangeType::VALUE_ERROR> SingleRange<VET,RangeType::VALUE_ERROR>::begin() const
+    {
+	return SingleIndex<VET,RangeType::VALUE_ERROR>(this, 0);
+    }
+
+    
+    SingleIndex<VET,RangeType::VALUE_ERROR> SingleRange<VET,RangeType::VALUE_ERROR>::end() const
+    {
+	return SingleIndex<VET,RangeType::VALUE_ERROR>(this, size());
+    }
+
+    // 
+
+    
+    size_t SingleRange<size_t,RangeType::LORENTZ>::get(size_t pos) const
+    {
+	return pos;
+    }
+
+    
+    size_t SingleRange<size_t,RangeType::LORENTZ>::getMeta(size_t metaPos) const
+    {
+	return metaPos;
+    }
+
+    
+    size_t SingleRange<size_t,RangeType::LORENTZ>::size() const
+    {
+	#ifdef LORENTZ_DIMENSION
+	return LORENTZ_DIMENSION;
+	#else
+	return 4;
+	#endif
+    }
+
+    
+    MultiRangeType SingleRange<size_t,RangeType::LORENTZ>::type() const
+    {
+	return MultiRangeType(RangeType::LORENTZ);
+    }
+    
+    
+    SingleIndex<size_t,RangeType::LORENTZ> SingleRange<size_t,RangeType::LORENTZ>::begin() const
+    {
+	return SingleIndex<size_t,RangeType::LORENTZ>(this, 0);
+    }
+
+    
+    SingleIndex<size_t,RangeType::LORENTZ> SingleRange<size_t,RangeType::LORENTZ>::end() const
+    {
+	return SingleIndex<size_t,RangeType::LORENTZ>(this, size());
+    }
     
     /******************
      *  SingleIndex   *	     
diff --git a/src/single_range.h b/src/single_range.h
index 4ac250b..40f1e98 100644
--- a/src/single_range.h
+++ b/src/single_range.h
@@ -83,6 +83,93 @@ namespace MultiArrayTools
 	std::vector<U> mSpace;
     };
 
+    // specializaions
+
+    template <>
+    class SingleRange<int,RangeType::SPACE> : public RangeBase<SingleIndex<int,RangeType::SPACE> >
+    {
+    public:
+	DEFAULT_MEMBERS(SingleRange);
+
+	SingleRange(int begin, int end);
+	
+	virtual size_t size() const override;
+	
+	int get(size_t pos) const;
+	size_t getMeta(int metaPos) const;
+
+	virtual MultiRangeType type() const override;
+	
+	SingleIndex<int,RangeType::SPACE> begin() const override;
+	SingleIndex<int,RangeType::SPACE> end() const override;
+	
+    protected:
+	int mBegin;
+	int mEnd;
+    };
+
+    template <>
+    class SingleRange<size_t,RangeType::ENSEMBLE> : public RangeBase<SingleIndex<size_t,RangeType::ENSEMBLE> >
+    {
+    public:
+	DEFAULT_MEMBERS(SingleRange);
+
+	SingleRange(size_t num);
+	
+	virtual size_t size() const override;
+	
+	size_t get(size_t pos) const;
+	size_t getMeta(size_t metaPos) const;
+
+	virtual MultiRangeType type() const override;
+	
+	SingleIndex<size_t,RangeType::ENSEMBLE> begin() const override;
+	SingleIndex<size_t,RangeType::ENSEMBLE> end() const override;
+	
+    protected:
+	size_t mNum;
+    };
+
+    enum class VET
+    {
+	VALUE = 0,
+	ERROR = 1
+    };
+
+    template <>
+    class SingleRange<VET,RangeType::VALUE_ERROR> : public RangeBase<SingleIndex<VET,RangeType::VALUE_ERROR> >
+    {
+    public:
+	DEFAULT_MEMBERS(SingleRange);
+
+	virtual size_t size() const override;
+	
+	VET get(size_t pos) const;
+	size_t getMeta(VET metaPos) const;
+
+	virtual MultiRangeType type() const override;
+	
+	SingleIndex<VET,RangeType::VALUE_ERROR> begin() const override;
+	SingleIndex<VET,RangeType::VALUE_ERROR> end() const override;
+    };
+
+    template <>
+    class SingleRange<size_t,RangeType::LORENTZ> : public RangeBase<SingleIndex<size_t,RangeType::LORENTZ> >
+    {
+    public:
+	DEFAULT_MEMBERS(SingleRange);
+
+	virtual size_t size() const override;
+	
+	size_t get(size_t pos) const;
+	size_t getMeta(size_t metaPos) const;
+
+	virtual MultiRangeType type() const override;
+	
+	SingleIndex<size_t,RangeType::LORENTZ> begin() const override;
+	SingleIndex<size_t,RangeType::LORENTZ> end() const override;
+    };
+    
 }
 
 #include "single_range.cc"