diff --git a/src/include/ranges/crange.h b/src/include/ranges/crange.h
index 6eb2b19..1a3bdbf 100644
--- a/src/include/ranges/crange.h
+++ b/src/include/ranges/crange.h
@@ -35,8 +35,9 @@ namespace CNORXZ
 
 	SizeT dim() const; // = 1
 	Sptr<RangeType> range() const;
-	SizeT getStepSize(SizeT n) const;
-
+	SizeT getStepSize(PtrId iptr) const;
+	Int getOffset(PtrId iptr) const;
+	
 	String stringMeta() const;
 	SizeT meta() const;
 	CIndex& at(const SizeT& metaPos);
diff --git a/src/include/ranges/dindex.h b/src/include/ranges/dindex.h
index 0312a45..52ee13e 100644
--- a/src/include/ranges/dindex.h
+++ b/src/include/ranges/dindex.h
@@ -39,7 +39,8 @@ namespace CNORXZ
 
 	SizeT dim() const;
 	RangePtr range() const;
-	SizeT getStepSize(SizeT n) const;
+	SizeT getStepSize(PtrId iptr) const;
+	Int getOffset(PtrId iptr) const;
 
 	String stringMeta() const;
 	DType meta() const;
diff --git a/src/include/ranges/index_base.h b/src/include/ranges/index_base.h
index 7c9c1cf..0bf2e5a 100644
--- a/src/include/ranges/index_base.h
+++ b/src/include/ranges/index_base.h
@@ -45,10 +45,9 @@ namespace CNORXZ
 	
 	SizeT dim() const { return THIS().dim(); }
 	auto range() const { return THIS().range(); }
-	// TODO: getStepSize(PtrId iptr) !!!!
-	SizeT getStepSize(SizeT n) const { return THIS().getStepSize(n); }
-	Int getOffset(PtrId iptr) const
-	{ if(mRel) if(iptr == mRel->ptrId()) return mPos - mRel.pos(); return 0; } 
+	SizeT getStepSize(PtrId iptr) const { return THIS().getStepSize(iptr); }
+	//SizeT getStepSize(SizeT n) const { return THIS().getStepSize(n); }
+	Int getOffset(PtrId iptr) const { return THIS().getOffset(iptr); }
 	
 	String stringMeta() const { return THIS().stringMeta(); }
 	auto meta() const { return THIS().meta(); }
@@ -77,7 +76,6 @@ namespace CNORXZ
 	IndexInterface(SizeT pos);
 
 	PtrId mPtrId = 0;
-	IndexPtr<I,MetaType> mRel;
     };
 
     template <class I, typename MetaType>
diff --git a/src/include/ranges/mrange.h b/src/include/ranges/mrange.h
index f8ad35b..f73af3d 100644
--- a/src/include/ranges/mrange.h
+++ b/src/include/ranges/mrange.h
@@ -54,7 +54,8 @@ namespace CNORXZ
 
 	SizeT dim();
 	Sptr<RangeType> range();
-	SizeT getStepSize(SizeT n);
+	SizeT getStepSize(PtrId iptr) const;
+	Int getOffset(PtrId iptr) const;
 
 	String stringMeta() const;
 	MetaType meta() const;
diff --git a/src/include/ranges/urange.cc.h b/src/include/ranges/urange.cc.h
index f605d46..d8da929 100644
--- a/src/include/ranges/urange.cc.h
+++ b/src/include/ranges/urange.cc.h
@@ -14,8 +14,8 @@ namespace CNORXZ
      *****************/
 
     template <typename MetaType>
-    UIndex<MetaType>::UIndex(const RangePtr& range) :
-	IndexInterface<UIndex<MetaType>,MetaType>(0),
+    UIndex<MetaType>::UIndex(const RangePtr& range, SizeT pos) :
+	IndexInterface<UIndex<MetaType>,MetaType>(pos),
 	mRangePtr(rangeCast<MetaType>(range)),
 	mMetaPtr(&mRangePtr->get(0))
     {}
@@ -41,6 +41,44 @@ namespace CNORXZ
 	return *this;
     }
 
+    template <typename MetaType>
+    UIndex<MetaType> UIndex<MetaType>::operator+(Int n) const
+    {
+	return UIndex(mRangePtr, IB::mPos + n);
+    }
+    
+    template <typename MetaType>
+    UIndex<MetaType> UIndex<MetaType>::operator-(Int n) const
+    {
+	return UIndex(mRangePtr, IB::mPos - n);
+    }
+    
+    template <typename MetaType>
+    UIndex<MetaType>& UIndex<MetaType>::operator+=(Int n)
+    {
+	IB::mPos += n;
+	return *this;
+    }
+    
+    template <typename MetaType>
+    UIndex<MetaType>& UIndex<MetaType>::operator-=(Int n)
+    {
+	IB::mPos -= n;
+	return *this;
+    }
+
+    template <typename MetaType>
+    const MetaType& UIndex<MetaType>::operator*() const
+    {
+	return mMetaPtr[IB::mPos];
+    }
+    
+    template <typename MetaType>
+    const MetaType* UIndex<MetaType>::operator->() const
+    {
+	return mMetaPtr + IB::mPos;
+    }
+	
     template <typename MetaType>
     Int UIndex<MetaType>::pp(PtrId idxPtrNum)
     {
@@ -87,9 +125,15 @@ namespace CNORXZ
     }
 
     template <typename MetaType>
-    SizeT UIndex<MetaType>::getStepSize(SizeT n) const
+    SizeT UIndex<MetaType>::getStepSize(PtrId iptr) const
     {
-	return 1;
+	return iptr == this->ptrId() ? 1 : 0;
+    }
+    
+    template <typename MetaType>
+    Int UIndex<MetaType>::getOffset(PtrId iptr) const
+    {
+	return 0;
     }
     /*
     template <typename MetaType>
diff --git a/src/include/ranges/urange.h b/src/include/ranges/urange.h
index 216e62a..3780bc6 100644
--- a/src/include/ranges/urange.h
+++ b/src/include/ranges/urange.h
@@ -19,7 +19,7 @@ namespace CNORXZ
 	typedef IndexInterface<UIndex<MetaType>,MetaType> IB;
 	typedef URange<MetaType> RangeType;
 
-	UIndex(const RangePtr& range);
+	UIndex(const RangePtr& range, SizeT pos = 0);
 	
 	UIndex& operator=(SizeT pos);
 	UIndex& operator++();
@@ -37,7 +37,8 @@ namespace CNORXZ
 
 	SizeT dim() const; // = 1
 	Sptr<RangeType> range() const;
-	SizeT getStepSize(SizeT n) const;
+	SizeT getStepSize(PtrId iptr) const;
+	Int getOffset(PtrId iptr) const;
 
 	String stringMeta() const;
 	const MetaType& meta() const;
diff --git a/src/include/ranges/xindex.cc.h b/src/include/ranges/xindex.cc.h
index 75032a5..fb2bc3f 100644
--- a/src/include/ranges/xindex.cc.h
+++ b/src/include/ranges/xindex.cc.h
@@ -117,9 +117,15 @@ namespace CNORXZ
     }
 
     template <class Index, typename Meta>
-    SizeT XIndex<Index,Meta>::getStepSize(SizeT n) const
+    SizeT XIndex<Index,Meta>::getStepSize(PtrId iptr) const
     {
-	return mI->getStepSize(n);
+	return mI->getStepSize(iptr);
+    }
+    
+    template <class Index, typename Meta>
+    Int XIndex<Index,Meta>::getOffset(PtrId iptr) const
+    {
+	return mI->getOffset(iptr);
     }
 
     template <class Index, typename Meta>
diff --git a/src/include/ranges/xindex.h b/src/include/ranges/xindex.h
index 4325a36..3f67e56 100644
--- a/src/include/ranges/xindex.h
+++ b/src/include/ranges/xindex.h
@@ -32,7 +32,8 @@ namespace CNORXZ
 
 	virtual SizeT dim() const = 0;
 	virtual RangePtr range() const = 0;
-	virtual SizeT getStepSize(SizeT n) const = 0;
+	virtual SizeT getStepSize(PtrId iptr) const = 0;
+	virtual Int getOffset(PtrId iptr) const = 0;
 
 	virtual String stringMeta() const = 0;
 	virtual DType meta() const = 0;
@@ -80,7 +81,8 @@ namespace CNORXZ
 
 	virtual SizeT dim() const override final;
 	virtual RangePtr range() const override final;
-	virtual SizeT getStepSize(SizeT n) const override final;
+	virtual SizeT getStepSize(PtrId iptr) const override final;
+	virtual Int getOffset(PtrId iptr) const override final;
 
 	virtual String stringMeta() const override final;
 	virtual DType meta() const override final;
diff --git a/src/include/ranges/yrange.h b/src/include/ranges/yrange.h
index 9337c0b..8a2c3c4 100644
--- a/src/include/ranges/yrange.h
+++ b/src/include/ranges/yrange.h
@@ -42,7 +42,8 @@ namespace CNORXZ
 
 	SizeT dim() const;
 	Sptr<YRange> range() const;
-	SizeT getStepSize(SizeT n) const;
+	SizeT getStepSize(PtrId iptr) const;
+	Int getOffset(PtrId iptr) const;
 
 	String stringMeta() const;
 	DType meta() const;
diff --git a/src/lib/ranges/crange.cc b/src/lib/ranges/crange.cc
index aa36ae1..e66953b 100644
--- a/src/lib/ranges/crange.cc
+++ b/src/lib/ranges/crange.cc
@@ -10,7 +10,7 @@ namespace CNORXZ
     CIndex::CIndex(const RangePtr& range, SizeT pos) :
 	IndexInterface<CIndex,SizeT>(pos), mRangePtr(rangeCast<RangeType>(range))
     {}
-
+    
     CIndex& CIndex::operator=(SizeT pos)
     {
 	IB::mPos = pos;
@@ -83,9 +83,14 @@ namespace CNORXZ
 	return mRangePtr;
     }
     
-    SizeT CIndex::getStepSize(SizeT n) const
+    SizeT CIndex::getStepSize(PtrId iptr) const
     {
-	return 1;
+	return iptr == this->ptrId() ? 1 : 0;
+    }
+
+    Int CIndex::getOffset(PtrId iptr) const
+    {
+	return 0;
     }
 
     String CIndex::stringMeta() const
diff --git a/src/lib/ranges/dindex.cc b/src/lib/ranges/dindex.cc
index f091afe..0a5bcf8 100644
--- a/src/lib/ranges/dindex.cc
+++ b/src/lib/ranges/dindex.cc
@@ -116,9 +116,14 @@ namespace CNORXZ
 	return mI->range();
     }
     
-    SizeT DIndex::getStepSize(SizeT n) const
+    SizeT DIndex::getStepSize(PtrId iptr) const
     {
-	return mI->getStepSize(n);
+	return mI->getStepSize(iptr);
+    }
+
+    Int DIndex::getOffset(PtrId iptr) const
+    {
+	return mI->getOffset(iptr);
     }
 
     String DIndex::stringMeta() const
diff --git a/src/lib/ranges/yrange.cc b/src/lib/ranges/yrange.cc
index bb81521..e283ac6 100644
--- a/src/lib/ranges/yrange.cc
+++ b/src/lib/ranges/yrange.cc
@@ -122,13 +122,20 @@ namespace CNORXZ
 	return mRangePtr;
     }
     
-    SizeT YIndex::getStepSize(SizeT n) const
+    SizeT YIndex::getStepSize(PtrId iptr) const
     {
 	assert(0);
 	// sub inds !!!
 	return 0;
     }
-    
+
+    Int YIndex::getOffset(PtrId iptr) const
+    {
+	assert(0);
+	// sub inds !!!
+	return 0;
+    }
+
     String YIndex::stringMeta() const
     {
 	String out = "[";