diff --git a/src/include/expressions.cc.h b/src/include/expressions.cc.h
new file mode 100644
index 0000000..846fbd4
--- /dev/null
+++ b/src/include/expressions.cc.h
@@ -0,0 +1,39 @@
+
+#include "expressions.h"
+
+namespace MultiArrayTools
+{
+
+    template <class Expr>
+    inline ExpressionHolder<Expr> Expressions1::ifor(size_t step,
+						     ExpressionHolder<Expr> ex) const
+    {
+	return iforx(step, ex);
+    }
+    
+    template <class Expr>
+    inline ExpressionHolder<Expr> Expressions1::iforh(size_t step,
+						      ExpressionHolder<Expr> ex) const
+    {
+	return iforhx(step, ex);
+    }
+
+    template <class Expr>
+    inline ExpressionHolder<Expr> Expressions1::ifori(size_t step, Expr ex) const
+    {
+	return iforxi(step, ex);
+    }
+    
+    template <class Expr>
+    inline ExpressionHolder<Expr> Expressions1::iforhi(size_t step, Expr ex) const
+    {
+	return iforhxi(step, ex);
+    }
+
+    template <class EC, class Index>
+    std::shared_ptr<EC> makeec(const std::shared_ptr<Index>& i)
+    {
+        return std::make_shared<EC>(i);
+    }
+
+} // namespace MultiArrayTools
diff --git a/src/include/expressions.h b/src/include/expressions.h
index 4911019..8e77097 100644
--- a/src/include/expressions.h
+++ b/src/include/expressions.h
@@ -21,13 +21,32 @@ namespace MultiArrayTools
     using DDMMA = MutableMultiArrayBase<double,DynamicRange<EC>>;
 
     template <class EC, class MA>
-    using oo = decltype(std::declval<MA>()(std::declval<std::shared_ptr<DynamicIndex<EC>>>()));
+    using oo = decltype(std::declval<MA>()(std::declval<const std::shared_ptr<DynamicIndex<EC>>&>()));
 
     template <template <class> class OpF, class... oos>
     using OO = Operation<double,OpF<double>,oos...>;
 
     template <class EC, template <class> class OpF, class... MAs>
     using OX = Operation<double,OpF<double>,oo<EC,MAs>...>;
+
+    template <class EC, class Second>
+    using AEXT = typename OperationMaster<double,Second,DynamicRange<EC>>::AssignmentExpr;
+
+    template <class EC, template <class> class OpF, class... MAs>
+    using AEX = AEXT<EC,OX<EC,OpF,MAs...>>;
+
+    template <class EC, template <class> class OpF>
+    using AEX_B_MM = AEX<EC,OpF,DDMMA<EC>,DDMMA<EC>>;
+
+    template <class EC, template <class> class OpF>
+    using AEX_B_MC = AEX<EC,OpF,DDMMA<EC>,DDMA<EC>>;
+
+    template <class EC, template <class> class OpF>
+    using AEX_B_CM = AEX<EC,OpF,DDMA<EC>,DDMMA<EC>>;
+
+    template <class EC, template <class> class OpF>
+    using AEX_B_CC = AEX<EC,OpF,DDMA<EC>,DDMA<EC>>;
+
     /*
     template <class EC>
     class ECInterface
@@ -53,57 +72,74 @@ namespace MultiArrayTools
     };
     */
     template <class EC, class Index>
-    EC makeec(const std::shared_ptr<Index>& i);
+    std::shared_ptr<EC> makeec(const std::shared_ptr<Index>& i);
 
 #define V_IFOR_X(Expr) \
-    virtual ExpressionHolder<Expr> iforx(size_t step, Expr ex) const = 0; \
-    virtual ExpressionHolder<Expr> iforhx(size_t step, Expr ex) const = 0
+    virtual ExpressionHolder<Expr> iforx(size_t step, ExpressionHolder<Expr> ex) const = 0; \
+    virtual ExpressionHolder<Expr> iforhx(size_t step, ExpressionHolder<Expr> ex) const = 0; \
+    virtual ExpressionHolder<Expr> iforxi(size_t step, Expr ex) const = 0; \
+    virtual ExpressionHolder<Expr> iforhxi(size_t step, Expr ex) const = 0
+
+#define V_IFOR_A(EC,OpF) \
+    V_IFOR_X(AEX_B_MM<EC Y() OpF>); \
+    V_IFOR_X(AEX_B_MC<EC Y() OpF>); \
+    V_IFOR_X(AEX_B_CM<EC Y() OpF>); \
+    V_IFOR_X(AEX_B_CC<EC Y() OpF>)
+    
 
     template <class Index>
     class E1;
-
+    
     class Expressions1 //: public ECInterface<Expressions1<X>>
     {
     public:
         typedef Expressions1 EX;
-        
-        template <class Index>
+
+	template <class Index>
         static auto make(const std::shared_ptr<Index>& i)
             -> decltype(makeec<E1<Index>>(i))
         {
             return makeec<E1<Index>>(i);
         }
-
+	
     private:
-        V_IFOR_X(OX<EX Y() plus Y() DDMA<EX> Y() DDMA<EX>>);
-        V_IFOR_X(OX<EX Y() minus Y() DDMA<EX> Y() DDMA<EX>>);
-        V_IFOR_X(OX<EX Y() multiplies Y() DDMA<EX> Y() DDMA<EX>>);
-        V_IFOR_X(OX<EX Y() divides Y() DDMA<EX> Y() DDMA<EX>>);
+        V_IFOR_A(EX,plus);
+        V_IFOR_A(EX,minus);
+        V_IFOR_A(EX,multiplies);
+        V_IFOR_A(EX,divides);
 
     public:
         template <class Expr>
-        auto ifor(size_t step, Expr ex) const
-            -> decltype(iforx(step, ex))
-        {
-            return iforx(step, ex);
-        }
+        inline ExpressionHolder<Expr> ifor(size_t step, ExpressionHolder<Expr> ex) const;
 
         template <class Expr>
-        auto iforh(size_t step, Expr ex) const
-            -> decltype(iforhx(step, ex))
-        {
-            return iforhx(step, ex);
-        }
+        inline ExpressionHolder<Expr> iforh(size_t step, ExpressionHolder<Expr> ex) const;
+
+	template <class Expr>
+        inline ExpressionHolder<Expr> ifori(size_t step, Expr ex) const;
+
+        template <class Expr>
+        inline ExpressionHolder<Expr> iforhi(size_t step, Expr ex) const;
 
     };
 
     
-#define O_IFOR_X(Expr,Ind) \
-    virtual ExpressionHolder<Expr> iforx(size_t step, Expr ex) const override final \
+#define D_IFOR_X(Expr,Ind) \
+    ExpressionHolder<Expr> iforx(size_t step, ExpressionHolder<Expr> ex) const \
     { return ExpressionHolder<Expr>(Ind->ifor(step, ex)); } \
-    virtual ExpressionHolder<Expr> iforhx(size_t step, Expr ex) const override final \
+    ExpressionHolder<Expr> iforhx(size_t step, ExpressionHolder<Expr> ex) const \
+    { return ExpressionHolder<Expr>(Ind->iforh(step, ex)); } \
+    ExpressionHolder<Expr> iforxi(size_t step, Expr ex) const \
+    { return ExpressionHolder<Expr>(Ind->ifor(step, ex)); } \
+    ExpressionHolder<Expr> iforhxi(size_t step, Expr ex) const \
     { return ExpressionHolder<Expr>(Ind->iforh(step, ex)); }
-    
+
+#define D_IFOR_A(EC,OpF,Ind) \
+    D_IFOR_X(AEX_B_MM<EC Y() OpF>,Ind); \
+    D_IFOR_X(AEX_B_MC<EC Y() OpF>,Ind); \
+    D_IFOR_X(AEX_B_CM<EC Y() OpF>,Ind); \
+    D_IFOR_X(AEX_B_CC<EC Y() OpF>,Ind)
+
     template <class Index>
     class E1 : public Expressions1
     {
@@ -115,10 +151,10 @@ namespace MultiArrayTools
         
         std::shared_ptr<Index> mI;
 
-        O_IFOR_X(OX<EX Y() plus Y() DDMA<EX> Y() DDMA<EX>>, mI);
-        O_IFOR_X(OX<EX Y() minus Y() DDMA<EX> Y() DDMA<EX>>, mI);
-        O_IFOR_X(OX<EX Y() multiplies Y() DDMA<EX> Y() DDMA<EX>>, mI);
-        O_IFOR_X(OX<EX Y() divides Y() DDMA<EX> Y() DDMA<EX>>, mI);
+        D_IFOR_A(EX,plus,mI);
+        D_IFOR_A(EX,minus,mI);
+        D_IFOR_A(EX,multiplies,mI);
+        D_IFOR_A(EX,divides,mI);
 
     public:
         E1(const E1& in) = default;
@@ -129,12 +165,6 @@ namespace MultiArrayTools
         E1(const std::shared_ptr<Index>& i) : mI(i) {} 
     };
 
-    template <class EC, class Index>
-    EC makeec(const std::shared_ptr<Index>& i)
-    {
-        return EC(i);
-    }
-
 
 } // namespace MultiArrayTools
 
diff --git a/src/include/helper_tools.cc.h b/src/include/helper_tools.cc.h
index 4d11dff..d67c4f8 100644
--- a/src/include/helper_tools.cc.h
+++ b/src/include/helper_tools.cc.h
@@ -114,4 +114,21 @@ namespace MultiArrayTools
     }
 
 
+    template <class EC, class MArray>
+    auto dynamic(const MArray& ma, bool slice)
+	-> std::shared_ptr<MultiArrayBase<typename MArray::value_type,DynamicRange<EC>>>
+    {
+	DynamicRangeFactory<EC> drf(ma.range()->space());
+	if(slice){
+	    return std::make_shared<ConstSlice<typename MArray::value_type,DynamicRange<EC>>>
+		( std::dynamic_pointer_cast<DynamicRange<EC>>( drf.create() ),
+		  ma.data() );
+	}
+	else {
+	    return std::make_shared<MultiArray<typename MArray::value_type,DynamicRange<EC>>>
+		( std::dynamic_pointer_cast<DynamicRange<EC>>( drf.create() ),
+		  ma.vdata() );
+	}
+    }
+
 }
diff --git a/src/include/helper_tools.h b/src/include/helper_tools.h
index b43ca02..884e6f5 100644
--- a/src/include/helper_tools.h
+++ b/src/include/helper_tools.h
@@ -59,6 +59,10 @@ namespace MultiArrayTools
     auto prtr(const MArray& ma)
 	-> decltype(ma.template getRangePtr<N>());
 
+    template <class EC, class MArray>
+    auto dynamic(const MArray& ma, bool slice = false)
+	-> std::shared_ptr<MultiArrayBase<typename MArray::value_type,DynamicRange<EC>>>;
+    
     template <class IndexType>
     inline void For(const std::shared_ptr<IndexType>& ind, const std::function<void(void)>& ll)
     {
diff --git a/src/include/multi_array_header.cc.h b/src/include/multi_array_header.cc.h
index dfca6df..06f7a00 100644
--- a/src/include/multi_array_header.cc.h
+++ b/src/include/multi_array_header.cc.h
@@ -6,5 +6,6 @@
 #include "multi_array_base.cc.h"
 #include "multi_array.cc.h"
 #include "slice.cc.h"
+#include "expressions.cc.h"
 
-
+#include "ranges/dynamic_range.cc.h"
diff --git a/src/include/ranges/dynamic_meta.h b/src/include/ranges/dynamic_meta.h
index 522da4f..5f054e8 100644
--- a/src/include/ranges/dynamic_meta.h
+++ b/src/include/ranges/dynamic_meta.h
@@ -9,6 +9,32 @@ namespace MultiArrayTools
 {
 
     typedef std::pair<const char*,size_t> DynamicMetaElem;
+
+    template <size_t N>
+    struct DynamicMetaSetter
+    {
+	template <typename... Us>
+	static inline void set(const std::tuple<Us...>& in, std::vector<DynamicMetaElem>& meta)
+	{
+	    typedef typename std::tuple_element<N,std::tuple<Us...>>::type elemtype;
+	    meta[N].first = reinterpret_cast<const char*>( &std::get<N>(in) );
+	    meta[N].second = sizeof(elemtype);
+	    DynamicMetaSetter<N-1>::set(in,meta);
+	}	    
+    };
+
+    template <>
+    struct DynamicMetaSetter<0>
+    {
+	template <typename... Us>
+	static inline void set(const std::tuple<Us...>& in, std::vector<DynamicMetaElem>& meta)
+	{
+	    typedef typename std::tuple_element<0,std::tuple<Us...>>::type elemtype;
+	    meta[0].first = reinterpret_cast<const char*>( &std::get<0>(in) );
+	    meta[0].second = sizeof(elemtype);
+	}	    
+    };
+
     
     class DynamicMetaT
     {
@@ -23,9 +49,9 @@ namespace MultiArrayTools
         DynamicMetaT& operator=(DynamicMetaT&& in) = default;
 
         template <typename... Us>
-        DynamicMetaT(const std::tuple<Us...>& meta)
+        DynamicMetaT(const std::tuple<Us...>* meta) : mMeta(sizeof...(Us))
         {
-            
+	    DynamicMetaSetter<sizeof...(Us)-1>::set(*meta,mMeta);
         }
         
         bool operator==(const DynamicMetaT& in) const;
diff --git a/src/include/ranges/dynamic_range.cc.h b/src/include/ranges/dynamic_range.cc.h
index 6498268..2a33be5 100644
--- a/src/include/ranges/dynamic_range.cc.h
+++ b/src/include/ranges/dynamic_range.cc.h
@@ -10,6 +10,48 @@ namespace MultiArrayTools
     {
         using namespace MultiArrayHelper;
     }
+
+    /*************************
+     *   IndexWrapperBase    *
+     *************************/
+
+    template <class ExpressionCollection>
+    template <class Expr>
+    ExpressionHolder<Expr>
+    IndexWrapperBase<ExpressionCollection>::ifor(size_t step, ExpressionHolder<Expr> ex) const
+    {
+	return mEc->ifor(step, ex);
+    }
+
+    template <class ExpressionCollection>
+    template <class Expr>
+    ExpressionHolder<Expr>
+    IndexWrapperBase<ExpressionCollection>::iforh(size_t step, ExpressionHolder<Expr> ex) const
+    {
+	return mEc->iforh(step, ex);
+    }
+
+    template <class ExpressionCollection>
+    template <class Expr>
+    ExpressionHolder<Expr>
+    IndexWrapperBase<ExpressionCollection>::ifori(size_t step, Expr ex) const
+    {
+	return mEc->ifori(step, ex);
+    }
+
+    template <class ExpressionCollection>
+    template <class Expr>
+    ExpressionHolder<Expr>
+    IndexWrapperBase<ExpressionCollection>::iforhi(size_t step, Expr ex) const
+    {
+	return mEc->iforhi(step, ex);
+    }
+
+    template <class Index, class ExpressionCollection>
+    size_t IndexWrapper<Index,ExpressionCollection>::getStepSizeComp(std::intptr_t j) const
+    {
+	return MultiArrayHelper::getStepSize(*mI, j);
+    }
     
     /****************************
      *   DynamicRangeFactory    *
@@ -101,9 +143,16 @@ namespace MultiArrayTools
 
     template <class EC>
     DynamicIndex<EC>::DynamicIndex(const std::shared_ptr<DynamicRange<EC> >& range) :
-	IndexInterface<DynamicIndex,MetaType>(range, 0)//,
-	//mExplicitRangePtr(std::dynamic_pointer_cast<RangeType>(IB::mRangePtr)),
-    {}
+	IndexInterface<DynamicIndex,MetaType>(range, 0),
+	mIVec(range->dim())
+    {
+	size_t xx = 1;
+	for(size_t i = mIVec.size()-1; i != 0; --i){
+	    mIVec[i].second = xx;
+	    xx *= range->sub(i)->size();
+	}
+	mIVec[0].second = xx;
+    }
 
     template <class EC>
     IndexType DynamicIndex<EC>::type() const
@@ -152,6 +201,20 @@ namespace MultiArrayTools
         mIVec = ivec;
         return *this;
     }
+
+    template <class EC>
+    template <class... Indices>
+    DynamicIndex<EC>& DynamicIndex<EC>::operator()(const std::shared_ptr<Indices>&... is)
+    {
+	std::vector<std::shared_ptr<IndexW<EC>>> tmp =
+	    { std::make_shared<IndexWrapper<Indices,EC>>(is)... };
+	
+	assert(mIVec.size() == tmp.size());
+	for(size_t i = 0; i != mIVec.size(); ++i){
+	    mIVec[i].first = tmp[i];
+	}
+	return *this;
+    }
     
     template <class EC>
     int DynamicIndex<EC>::pp(std::intptr_t idxPtrNum)
@@ -207,7 +270,7 @@ namespace MultiArrayTools
     template <class EC>
     size_t DynamicIndex<EC>::dim() const // = 1
     {
-	return 1;
+	return mIVec.size();
     }
 
     template <class EC>
@@ -261,10 +324,37 @@ namespace MultiArrayTools
 	std::cout << id() << "[" << reinterpret_cast<std::intptr_t>(this)
 		  << "](" << IB::mRangePtr << "): " /*<< meta().first*/ << std::endl;
     }
-    
+
+    template <class Expr>
+    struct ForMaker
+    {
+	template <class IVecT>
+	static inline auto mk(size_t i, size_t step, ExpressionHolder<Expr> ex, 
+			      const IVecT& ivec, bool hidden = false)
+	    -> ExpressionHolder<Expr>
+	{
+	    if(i != 0){
+		auto& ii = *ivec[i].first;
+		return mk(i-1, step,
+			  (hidden ? ii.iforh(step*ivec[i].second, ex) :
+			   ii.ifor(step*ivec[i].second, ex)),
+			  ivec, hidden);
+	    }
+	    else {
+		auto& ii = *ivec[0].first;
+		return hidden ? ii.iforh(step*ivec[i].second, ex) :
+		    ii.ifor(step*ivec[i].second, ex);
+	    }		
+	}
+    };
+
+    /*
     template <class EC>
-    inline DynamicExpression DynamicIndex<EC>::mkFor(size_t i, size_t step,
-						   DynamicExpression ex, bool hidden) const
+    template <class Expr>
+    inline auto DynamicIndex<EC>::mkFor(size_t i, size_t step,
+					ExpressionHolder<Expr> ex,
+					bool hidden) const
+	-> ExpressionHolder<Expr>
     {
 	if(i != 0){
 	    auto& ii = *mIVec[i].first;
@@ -275,23 +365,21 @@ namespace MultiArrayTools
 	    return hidden ? ii.iforh(step, ex) : ii.ifor(step, ex);
 	}		
     }
-
+    */
     template <class EC>
     template <class Expr>
-    auto DynamicIndex<EC>::ifor(size_t step, Expr ex) const
-        -> DynamicExpression
+    ExpressionHolder<Expr> DynamicIndex<EC>::ifor(size_t step, Expr ex) const
     {
-	DynamicExpression expr(std::make_shared<Expr>(ex));
-	return mkFor(mIVec.size()-1, step, expr);
+	return ForMaker<Expr>::mk(mIVec.size()-2, step, mIVec.back().first->ifori(step,ex),
+				  mIVec);
     }
 
     template <class EC>
     template <class Expr>
-    auto DynamicIndex<EC>::iforh(size_t step, Expr ex) const
-        -> DynamicExpression
+    ExpressionHolder<Expr> DynamicIndex<EC>::iforh(size_t step, Expr ex) const
     {
-	DynamicExpression expr(std::make_shared<Expr>(ex));
-	return mkFor(mIVec.size()-1, step, expr, true);
+	return ForMaker<Expr>::mk(mIVec.size()-2, step, mIVec.back().first->iforhi(step,ex),
+				  mIVec, true);
     }
 
 
diff --git a/src/include/ranges/dynamic_range.h b/src/include/ranges/dynamic_range.h
index ce6f9cc..8c14db9 100644
--- a/src/include/ranges/dynamic_range.h
+++ b/src/include/ranges/dynamic_range.h
@@ -19,9 +19,14 @@
 
 namespace MultiArrayTools
 {
+    namespace
+    {
+	using namespace MultiArrayHelper;
+    }
+    //using MultiArrayHelper::DynamicExpression;
 
-    using MultiArrayHelper::DynamicExpression;
-
+    //using MultiArrayHelper::ExpressionHolder;
+    
     template <class ExpressionCollection>
     class IndexWrapperBase
     {
@@ -46,7 +51,7 @@ namespace MultiArrayTools
 
 	virtual std::string stringMeta() const = 0;
 	//virtual DynamicMetaT meta() const = 0;
-	virtual const DynamicMetaT* metaPtr() const = 0;
+	//virtual const DynamicMetaT* metaPtr() const = 0;
 	//virtual IndexWrapperBase& at(const U& metaPos) = 0;
 	//virtual size_t posAt(const U& metaPos) const = 0;
 
@@ -64,16 +69,19 @@ namespace MultiArrayTools
         virtual size_t getStepSizeComp(std::intptr_t j) const = 0;
         
         virtual std::intptr_t get() const = 0;
+	virtual std::intptr_t ptrNum() const = 0;
+	
+        template <class Expr>
+        ExpressionHolder<Expr> ifor(size_t step, ExpressionHolder<Expr> ex) const;
 
         template <class Expr>
-        auto ifor(size_t step, Expr ex) const
-            -> decltype(mEc->ifor(step, ex))
-        { return mEc->ifor(step, ex); }
+        ExpressionHolder<Expr> iforh(size_t step, ExpressionHolder<Expr> ex) const;
+
+	template <class Expr>
+        ExpressionHolder<Expr> ifori(size_t step, Expr ex) const;
 
         template <class Expr>
-        auto iforh(size_t step, Expr ex) const
-            -> decltype(mEc->iforh(step, ex))
-        { return mEc->iforh(step, ex); }
+        ExpressionHolder<Expr> iforhi(size_t step, Expr ex) const;
 
     };
 
@@ -85,6 +93,10 @@ namespace MultiArrayTools
     {
     public:
         typedef IndexWrapperBase<ExpressionCollection> IWB;
+	typedef typename Index::MetaType MetaType;
+
+	static constexpr IndexType sType() { return IndexType::SINGLE; }
+	
     protected:
         IndexWrapper() = default;
 
@@ -113,8 +125,8 @@ namespace MultiArrayTools
 	virtual int mm(std::intptr_t idxPtrNum) final { return mI->mm(idxPtrNum); }
 
 	virtual std::string stringMeta() const final { return mI->stringMeta(); }
-	virtual DynamicMetaT meta() const final { return DynamicMetaT(mI->meta()); }
-	virtual const DynamicMetaT* metaPtr() const final { return nullptr; }
+	//virtual DynamicMetaT meta() const final { return DynamicMetaT(mI->meta()); }
+	//virtual const DynamicMetaT* metaPtr() const final { return nullptr; }
 	IndexWrapper& at(const typename Index::MetaType& metaPos) { mI->at(metaPos); return *this; }
 	size_t posAt(const typename Index::MetaType& metaPos) const { return mI->posAt(metaPos); }
 
@@ -127,9 +139,10 @@ namespace MultiArrayTools
 	virtual std::shared_ptr<RangeBase> range() const final { return mI->range(); }
         
         virtual size_t getStepSize(size_t n) const final { return mI->getStepSize(n); }
-        virtual size_t getStepSizeComp(std::intptr_t j) const final { return getStepSize(*this, j); }
+        virtual size_t getStepSizeComp(std::intptr_t j) const final;
         
         virtual std::intptr_t get() const final { return reinterpret_cast<std::intptr_t>(mI.get()); }
+	virtual std::intptr_t ptrNum() const final { return mI->ptrNum(); }
 	
     };
     
@@ -143,9 +156,6 @@ namespace MultiArrayTools
         
         IVecT mIVec;
 
-	inline DynamicExpression mkFor(size_t i, size_t step,
-					 DynamicExpression ex, bool hidden = false) const;	
-
     public:
         typedef IndexInterface<DynamicIndex<EC>,DynamicMetaT> IB;
 	typedef DynamicMetaT MetaType;
@@ -167,6 +177,9 @@ namespace MultiArrayTools
 	DynamicIndex& operator--();
 
         DynamicIndex& operator()(const IVecT& ivec);
+
+	template <class... Indices>
+	DynamicIndex& operator()(const std::shared_ptr<Indices>&... is);
         
 	int pp(std::intptr_t idxPtrNum);
 	int mm(std::intptr_t idxPtrNum);
@@ -196,12 +209,10 @@ namespace MultiArrayTools
 	void print(size_t offset);
 
 	template <class Expr>
-	auto ifor(size_t step, Expr ex) const
-	    -> DynamicExpression;
+	ExpressionHolder<Expr> ifor(size_t step, Expr ex) const;
 
 	template <class Expr>
-	auto iforh(size_t step, Expr ex) const
-	    -> DynamicExpression;
+	ExpressionHolder<Expr> iforh(size_t step, Expr ex) const;
 
     };    
 
@@ -335,7 +346,8 @@ namespace MultiArrayHelper
     {
         size_t ss = 0;
         size_t sx = 1;
-        for(size_t i = ii.dim(); i != 0; --i){
+        for(size_t k = ii.dim(); k != 0; --k){
+	    const size_t i = k-1;
             const auto& ni = ii.get(i);
             const size_t max = ni.max();
             const size_t tmp = ni.getStepSizeComp(j);
@@ -347,6 +359,6 @@ namespace MultiArrayHelper
 
 }
 
-#include "dynamic_range.cc.h"
+//#include "dynamic_range.cc.h"
 
 #endif
diff --git a/src/include/ranges/rbase_def.h b/src/include/ranges/rbase_def.h
index 954f310..80c2796 100644
--- a/src/include/ranges/rbase_def.h
+++ b/src/include/ranges/rbase_def.h
@@ -5,6 +5,17 @@
 
 #include <cstdlib>
 
+#include <iostream>
+#ifndef CHECK
+#define CHECK std::cout << __FILE__ << ": @" << __LINE__ << " in " << __func__ << std::endl;
+#endif
+#ifndef VCHECK
+#define VCHECK(a) std::cout << __FILE__ << ": @" << __LINE__ \
+  << " in " << __func__ << ": " << #a << " = " << a << std::endl;
+#endif
+
+
+
 namespace MultiArrayTools
 {
 
diff --git a/src/include/ranges/rpack_num.h b/src/include/ranges/rpack_num.h
index 4b9c572..470934d 100644
--- a/src/include/ranges/rpack_num.h
+++ b/src/include/ranges/rpack_num.h
@@ -584,8 +584,6 @@ namespace MultiArrayHelper
 	template <class Index>
 	static inline size_t getStepSize(const Index& ii, std::intptr_t j)
 	{
-	    //VCHECK(ii.ptrNum());
-	    //VCHECK(j);
 	    return ii.ptrNum() == j ? 1 : 0;
 	}
     };
diff --git a/src/include/xfor/xfor.h b/src/include/xfor/xfor.h
index 9382f49..4b11d76 100644
--- a/src/include/xfor/xfor.h
+++ b/src/include/xfor/xfor.h
@@ -9,6 +9,9 @@
 #include "xfor/for_utils.h"
 #include "xfor/exttype.h"
 
+#define VCHECK(a) std::cout << __FILE__ << ": @" << __LINE__ \
+    << " in " << __func__ << ": " << #a << " = " << a << std::endl; 
+
 namespace MultiArrayHelper
 {
 
@@ -271,8 +274,6 @@ namespace MultiArrayHelper
         mExpr(expr), mExt(mExpr.rootSteps( reinterpret_cast<std::intptr_t>( mIndPtr )))
     {
 	assert(mIndPtr != nullptr);
-	//VCHECK(mIndPtr->id());
-	//VCHECK(mIndPtr->max());
     }
 
     template <class IndexClass, class Expr, ForType FT>
@@ -282,8 +283,6 @@ namespace MultiArrayHelper
         mExpr(expr), mExt(mExpr.rootSteps( reinterpret_cast<std::intptr_t>( mIndPtr )))
     {
 	assert(mIndPtr != nullptr);
-	//VCHECK(mIndPtr->id());
-	//VCHECK(mIndPtr->max());
     }
 
     template <class IndexClass, class Expr, ForType FT>
@@ -501,14 +500,14 @@ namespace MultiArrayHelper
     auto ExpressionHolder<Expr>::rootSteps(std::intptr_t iPtrNum) const
 	-> ExtType
     {
-	return *reinterpret_cast<ExtType*>( mExpr.dRootSteps(iPtrNum).first );
+	return *reinterpret_cast<ExtType const*>( mExpr.dRootSteps(iPtrNum).first );
     }
 
     template <class Expr>
     auto ExpressionHolder<Expr>::extension() const
 	-> ExtType
     {
-	return *reinterpret_cast<ExtType*>( mExpr.dExtension().first );
+	return *reinterpret_cast<ExtType const*>( mExpr.dExtension().first );
     }
 
 
diff --git a/src/tests/op_unit_test.cc b/src/tests/op_unit_test.cc
index 1412f28..4260d38 100644
--- a/src/tests/op_unit_test.cc
+++ b/src/tests/op_unit_test.cc
@@ -64,6 +64,8 @@ namespace {
 	return std::make_tuple(static_cast<size_t>( ts )...);
     }
 
+    typedef Expressions1 EC1;
+    
     template <typename T>
     struct Pow
     {
@@ -153,6 +155,8 @@ namespace {
 	std::vector<double> v2 = { 8.870, 4.790 };
 	std::vector<double> v3 = { 0.353, 4.005, 1.070, 2.310, 9.243, 2.911 };
 	std::vector<double> v4 = { 1.470, 2.210 };
+	std::vector<double> v5 = { 30.932, -33.693, -26.205, -15.504, 21.227, 17.829,
+				   -14.364, -1.868, -25.703, 13.836, 23.563, 41.339 };
     };
 
     class MapTest : public ::testing::Test
@@ -485,46 +489,7 @@ namespace {
 		  << std::endl;
 	std::cout << "ratio: " << static_cast<double>( end - begin ) / static_cast<double>( end2 - begin2 ) << std::endl;
     }    
-    /*
-    TEST_F(OpTest_Performance, PCheck)
-    {
-	MultiArray<double,MRange> ma2(mrptr, cv2);
-	MultiArray<double,SRange> ma1(sr1ptr, cv1);
-	MultiArray<double,MRange> res(mrptr);
 
-	auto si1 = MAT::getIndex(sr1ptr);
-	auto si2 = MAT::getIndex(sr2ptr);
-	auto mi = MAT::getIndex(mrptr);
-	(*mi)(si2, si1);
-
-	std::clock_t begin = std::clock();
-	
-	res(mi) = ma2(mi) * ma1(si1);
-
-	std::clock_t end = std::clock();
-	std::cout << "MultiArray time: " << static_cast<double>( end - begin ) / CLOCKS_PER_SEC
-		  << std::endl;
-
-	std::vector<double> res2(vs1*vs2);
-	std::clock_t begin2 = std::clock();
-	
-	for(size_t i = 0; i != vs2; ++i){
-	    for(size_t j = 0; j != vs1; ++j){
-		res2[i*vs1 + j] = cv1[j] * cv2[i*vs1 + j];
-	    }
-	}
-
-	std::clock_t end2 = std::clock();
-	std::cout << "std::vector - for loop time: " << static_cast<double>( end2 - begin2 ) / CLOCKS_PER_SEC
-		  << std::endl;
-
-	std::cout << "ratio: " << static_cast<double>( end - begin ) / static_cast<double>( end2 - begin2 ) << std::endl;
-
-	EXPECT_EQ( xround( res.at(mkt(7,9)) ), xround(res2[7*vs1 + 9]) );
-	//EXPECT_EQ( xround( res.at(mkt(700,900)) ), xround(res2[700*vs1 + 900]) );
-	
-    }
-    */
     TEST_F(OpTest_1Dim, ExecOp)
     {
 	MultiArray<double,SRange> ma1(srptr, v1);
@@ -681,6 +646,53 @@ namespace {
 	EXPECT_EQ( xround( res.at(mkt(mkt('3','b'),'B')) ), xround(2.911 / ( 1 + 4.790 / 2.210) ) );
     }
 
+    TEST_F(OpTest_MDim, ExecDOp)
+    {
+	//typedef MultiArray<double,AnonymousRange> AMA;
+	typedef MultiArray<double,DynamicRange<EC1> > DMA;
+	
+	MultiArray<double,MRange,SRange> ma1(mr1ptr,sr4ptr,v5);
+	MultiArray<double,SRange> ma2(sr2ptr,v1);
+	MultiArray<double,SRange,MRange> res(sr4ptr,mr1ptr);
+
+	DMA dma1 = *std::dynamic_pointer_cast<DMA>( dynamic<EC1>( ma1 ) );
+	DMA dma2 = *std::dynamic_pointer_cast<DMA>( dynamic<EC1>( ma2 ) );
+	DMA dres = *std::dynamic_pointer_cast<DMA>( dynamic<EC1>( res ) );
+	
+	auto si2 = MAT::getIndex( sr2ptr );
+	auto si3 = MAT::getIndex( sr3ptr );
+	auto si4 = MAT::getIndex( sr4ptr );
+	auto mi = MAT::getIndex( mr1ptr );
+	(*mi)(si2,si3);
+
+	auto di1 = MAT::getIndex( MAT::rptr<0>( dma1 ) );
+	auto di2 = MAT::getIndex( MAT::rptr<0>( dma2 ) );
+	auto dir = MAT::getIndex( MAT::rptr<0>( dres ) );
+
+	(*di1)(mi,si4);
+	(*di2)(si2);
+	(*dir)(si4,mi);
+
+	dres(dir) = dma1(di1) + dma2(di2);
+
+	MultiArray<double,SRange,MRange> res2(sr4ptr,mr1ptr,dres.vdata());
+	
+	EXPECT_EQ( xround( res2.at( mkt('A',mkt('1','a')) ) ), xround( 30.932 + 2.917 ) );
+	EXPECT_EQ( xround( res2.at( mkt('A',mkt('1','b')) ) ), xround( -26.205 + 2.917 ) );
+	EXPECT_EQ( xround( res2.at( mkt('A',mkt('2','a')) ) ), xround( 21.227 + 9.436 ) );
+	EXPECT_EQ( xround( res2.at( mkt('A',mkt('2','b')) ) ), xround( -14.364 + 9.436 ) );
+	EXPECT_EQ( xround( res2.at( mkt('A',mkt('3','a')) ) ), xround( -25.703 + 0.373 ) );
+	EXPECT_EQ( xround( res2.at( mkt('A',mkt('3','b')) ) ), xround( 23.563 + 0.373 ) );
+
+	EXPECT_EQ( xround( res2.at( mkt('B',mkt('1','a')) ) ), xround( -33.693 + 2.917 ) );
+	EXPECT_EQ( xround( res2.at( mkt('B',mkt('1','b')) ) ), xround( -15.504 + 2.917 ) );
+	EXPECT_EQ( xround( res2.at( mkt('B',mkt('2','a')) ) ), xround( 17.829 + 9.436 ) );
+	EXPECT_EQ( xround( res2.at( mkt('B',mkt('2','b')) ) ), xround( -1.868 + 9.436 ) );
+	EXPECT_EQ( xround( res2.at( mkt('B',mkt('3','a')) ) ), xround( 13.836 + 0.373 ) );
+	EXPECT_EQ( xround( res2.at( mkt('B',mkt('3','b')) ) ), xround( 41.339 + 0.373 ) );
+	
+    }
+
     TEST_F(OpTest_MDim, ExecOp3)
     {
 	MultiArray<double,MRange,SRange> res(mr1ptr,sr4ptr);
@@ -762,6 +774,7 @@ namespace {
 	EXPECT_EQ( xround( ma7.at(mkt('3','B')).at(mkt('l','b')) ),
 		   xround( ma4.at(mkt('l','3','b','B')) ) );
 }
+
     /*
     TEST_F(OpTest_MDim, ExecAnonOp1)
     {