diff --git a/src/include/multi_array_operation.h b/src/include/multi_array_operation.h
index de3451b..07a4600 100644
--- a/src/include/multi_array_operation.h
+++ b/src/include/multi_array_operation.h
@@ -591,6 +591,7 @@ namespace MultiArrayTools
     inline void OperationMaster<T,OpClass,Ranges...>::AssignmentExpr::
     operator()(size_t start, ExtType last) const
     {
+	//VCHECK(mSec.template get<ExtType>(last));
 	mM.add(start, mSec.template get<ExtType>(last) );
     }
     
diff --git a/src/include/ranges/container_range.h b/src/include/ranges/container_range.h
index a7d6e4f..bff51cf 100644
--- a/src/include/ranges/container_range.h
+++ b/src/include/ranges/container_range.h
@@ -66,6 +66,9 @@ namespace MultiArrayTools
 	template <size_t N>
 	auto getPtr() const -> decltype( std::get<N>( mIPack ) )&;
 
+	template <size_t N>
+	size_t getBlockSize() const { return std::get<N>(mBlockSizes); }
+
 	const IndexPack& pack() const { return mIPack; }
 	
 	ContainerIndex& sync(); // recalculate 'IB::mPos' when externalControl == true
diff --git a/src/include/ranges/multi_range.h b/src/include/ranges/multi_range.h
index 795013f..ca75474 100644
--- a/src/include/ranges/multi_range.h
+++ b/src/include/ranges/multi_range.h
@@ -75,6 +75,9 @@ namespace MultiArrayTools
 
 	template <size_t N>
 	auto getPtr() const -> decltype( std::get<N>( mIPack ) )&;
+
+	template <size_t N>
+	size_t getBlockSize() const { return std::get<N>(mBlockSizes); }
 	
 	// raplace instances (in contrast to its analogon in ContainerIndex
 	// MultiIndices CANNOT be influences be its subindices, so there is
diff --git a/src/include/ranges/rpack_num.h b/src/include/ranges/rpack_num.h
index 636a3ed..5288b4a 100644
--- a/src/include/ranges/rpack_num.h
+++ b/src/include/ranges/rpack_num.h
@@ -276,7 +276,8 @@ namespace MultiArrayHelper
 	    const auto& ni = ii.template get<N>();
 	    const size_t max = ni.max();
 	    const size_t tmp = getStepSize(ni, j);
-	    ss += tmp * sx;
+	    //ss += tmp * sx;
+	    ss += tmp * ii.template getBlockSize<N+1>();
 	    sx *= max;
 	    RPackNum<N-1>::getStepSizeX(ii, j, ss, sx);
 	}
@@ -507,7 +508,8 @@ namespace MultiArrayHelper
 	    const auto& ni = ii.template get<0>();
 	    const size_t max = ni.max();
 	    const size_t tmp = getStepSize(ni, j);
-	    ss += tmp * sx;
+	    //ss += tmp * sx;
+	    ss += tmp * ii.template getBlockSize<1>();
 	    sx *= max;
 	}
 
diff --git a/src/include/slice.h b/src/include/slice.h
index 208e205..12e4ee5 100644
--- a/src/include/slice.h
+++ b/src/include/slice.h
@@ -15,6 +15,8 @@ namespace MultiArrayTools
 	typedef ContainerRange<T,SRanges...> CRange;
 	typedef MultiArrayBase<T,SRanges...> MAB;
 	typedef ContainerIndex<T,typename SRanges::IndexType...> IType;
+
+	using MultiArrayBase<T,SRanges...>::operator();
 	
 	DEFAULT_MEMBERS(ConstSlice);
 
@@ -53,6 +55,9 @@ namespace MultiArrayTools
 	typedef ContainerRange<T,SRanges...> CRange;
 	typedef MultiArrayBase<T,SRanges...> MAB;
 	typedef ContainerIndex<T,typename SRanges::IndexType...> IType;
+
+	using MultiArrayBase<T,SRanges...>::operator();
+	using MutableMultiArrayBase<T,SRanges...>::operator();
 	
 	DEFAULT_MEMBERS(Slice);
 
diff --git a/src/tests/op_unit_test.cc b/src/tests/op_unit_test.cc
index 58955ce..69eb9e3 100644
--- a/src/tests/op_unit_test.cc
+++ b/src/tests/op_unit_test.cc
@@ -469,7 +469,7 @@ 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);
@@ -508,7 +508,7 @@ namespace {
 	//EXPECT_EQ( xround( res.at(mkt(700,900)) ), xround(res2[700*vs1 + 900]) );
 	
     }
-
+    */
     TEST_F(OpTest_1Dim, ExecOp)
     {
 	MultiArray<double,SRange> ma1(srptr, v1);
@@ -675,10 +675,10 @@ namespace {
 	MultiArray<double,SRange> ma5(sr1ptr, v3);
 	MultiArray<double,SRange> ma6(sr3ptr, v2);
 	
-	auto si0 = MAT::getIndex( sr1ptr );
-	auto si1 = MAT::getIndex( sr2ptr );
-	auto si2 = MAT::getIndex( sr3ptr );
-	auto si3 = MAT::getIndex( sr4ptr );
+	auto si0 = MAT::getIndex( sr1ptr ); // 'x'
+	auto si1 = MAT::getIndex( sr2ptr ); // '1'
+	auto si2 = MAT::getIndex( sr3ptr ); // 'a'
+	auto si3 = MAT::getIndex( sr4ptr ); // 'A'
 	auto mi = MAT::getIndex( mr1ptr );
 	mi->operator()(si1,si2);
 	
@@ -704,10 +704,20 @@ namespace {
 	ma7(si1,si3) = ma4(si0,si1,si2,si3).slc(si0,si2);
 
 	si1->at('1');
-	si3->at('A');
-	Slice<double,SRange,SRange> sl(sr1ptr,sr3ptr);
-	sl.define(si2,si3) = ma4(si0,si1,si2,si3);
+	si0->at('x');
+	(*si2) = 0;
+	(*si3) = 0;
+	Slice<double,SRange,SRange> sl(sr4ptr,sr3ptr);
+	sl.define(si3,si2) = ma4(si0,si1,si2,si3);
+	MultiArrayBase<double,SRange,SRange>& slb = sl;
+	
+	MultiArray<double,SRange,SRange> ma8(sr3ptr,sr4ptr);
+	//ma8(si2,si3) = ma4(si0,si1,si2,si3);
+	ma8(si2,si3) = slb(si3,si2);
 
+	EXPECT_EQ( xround( ma8.at(mkt('a','A')) ), xround( sl.at(mkt('A','a')) ) );
+	EXPECT_EQ( xround( ma8.at(mkt('b','A')) ), xround( sl.at(mkt('A','b')) ) );
+	
 	EXPECT_EQ( xround( ma7.at(mkt('1','A')).at(mkt('x','a')) ),
 		   xround( ma4.at(mkt('x','1','a','A')) ) );
 	EXPECT_EQ( xround( ma7.at(mkt('2','A')).at(mkt('x','a')) ),