diff --git a/src/include/ranges/prange.cc.h b/src/include/ranges/prange.cc.h
index 239375d..fc41d7f 100644
--- a/src/include/ranges/prange.cc.h
+++ b/src/include/ranges/prange.cc.h
@@ -3,6 +3,7 @@
 #define __cxz_prange_cc_h__
 
 #include "prange.h"
+#include "urange.h"
 
 namespace CNORXZ
 {
@@ -130,7 +131,8 @@ namespace CNORXZ
     template <class IndexT>
     RangePtr PIndex<IndexT>::prange(const PIndex<IndexT>& last) const
     {
-	CXZ_ASSERT(last > *this, "got last index position smaller than begin index position");
+	CXZ_ASSERT(last >= *this, "got last index position (" << last.lex()
+		   << ") smaller than begin index position (" << lex() << ")");
 	auto oi = *orig();
 	auto olast = *last.orig();
 	const SizeT beginPos = oi.lex();
@@ -138,7 +140,8 @@ namespace CNORXZ
 	for(auto i = oi; i != olast+1; ++i){
 	    parts[i.lex()-beginPos] = i.lex();
 	}
-	return CNORXZ::prange(mRangePtr->orig(), parts);
+	auto x = CNORXZ::prange(mRangePtr->orig(), parts);
+	return x;
     }
 
     template <class IndexT>
@@ -268,7 +271,8 @@ namespace CNORXZ
     template <class RangeT>
     void PRangeFactory<RangeT>::make()
     {
-	const Vector<Uuid> key = { mRange->id() };
+	RangePtr purange = urange(mParts);
+	const Vector<Uuid> key = { mRange->id(), purange->id() };
 	const auto& info = typeid(PRange<RangeT>);
 	mProd = this->fromCreated(info, key);
 	if(mProd == nullptr) {
@@ -351,7 +355,7 @@ namespace CNORXZ
 	mRange(range), mParts(_parts)
     {
 	const auto max = std::max_element( mParts.begin(), mParts.end() );
-	mParts.push_back( *max );
+	mParts.push_back( *max+1 );
     }
 
     template <class RangeT>
diff --git a/src/include/ranges/urange.cc.h b/src/include/ranges/urange.cc.h
index 43fbfe3..94744c1 100644
--- a/src/include/ranges/urange.cc.h
+++ b/src/include/ranges/urange.cc.h
@@ -130,7 +130,8 @@ namespace CNORXZ
     template <typename MetaT>
     RangePtr UIndex<MetaT>::prange(const UIndex<MetaT>& last) const
     {
-	CXZ_ASSERT(last > *this, "got last index position smaller than begin index position");
+	CXZ_ASSERT(last >= *this, "got last index position (" << last.lex()
+		   << ") smaller than begin index position (" << lex() << ")");
 	const SizeT beginPos = lex();
 	Vector<SizeT> parts(last.lex()-beginPos+1);
 	for(auto i = *this; i != last+1; ++i){
@@ -439,6 +440,12 @@ namespace CNORXZ
 	    return nullptr;
 	}
     }
+
+    template <typename MetaT>
+    RangePtr urange(const Vector<MetaT>& space)
+    {
+	return URangeFactory<MetaT>(space).create();
+    }
     
 }
 
diff --git a/src/include/ranges/urange.h b/src/include/ranges/urange.h
index 0ef9c21..2eeb6a3 100644
--- a/src/include/ranges/urange.h
+++ b/src/include/ranges/urange.h
@@ -136,6 +136,9 @@ namespace CNORXZ
     {
 	static Sptr<URange<MetaType>> func(const RangePtr& r);
     };
+
+    template <typename MetaT>
+    RangePtr urange(const Vector<MetaT>& space);
 }
 
 #endif
diff --git a/src/lib/ranges/crange.cc b/src/lib/ranges/crange.cc
index a52e6ba..015bf67 100644
--- a/src/lib/ranges/crange.cc
+++ b/src/lib/ranges/crange.cc
@@ -119,7 +119,7 @@ namespace CNORXZ
 
     RangePtr CIndex::prange(const CIndex& last) const
     {
-	CXZ_ASSERT(last > *this, "got last index position (" << last.lex()
+	CXZ_ASSERT(last >= *this, "got last index position (" << last.lex()
 		   << ") smaller than begin index position (" << lex() << ")");
 	const SizeT beginPos = lex();
 	Vector<SizeT> parts(last.lex() - beginPos + 1);
diff --git a/src/tests/range_unit_test.cc b/src/tests/range_unit_test.cc
index b6c4802..ee4bfeb 100644
--- a/src/tests/range_unit_test.cc
+++ b/src/tests/range_unit_test.cc
@@ -513,6 +513,35 @@ namespace
 	for(auto i = prx->begin(); i != prx->end(); ++i){
 	    EXPECT_TRUE(*i == mkm(i.lex()));
 	}
+
+	const SizeT begI2 = 1;
+	const SizeT lastI2 = 3;
+	const SizeT begJ2 = 0;
+	const SizeT lastJ2 = 0;
+
+	const SizeT begPos2 = begI2 * (lastJ-begJ+1) + begJ2;
+	const SizeT lastPos2 = lastI2 * (lastJ-begJ+1) + lastJ2;
+	const SizeT pSize2 = (lastI2-begI2+1)*(lastJ2-begJ2+1);
+
+	auto beg2 = prx->begin();
+	auto last2 = prx->begin();
+
+	beg2 = begPos2;
+	last2 = lastPos2;
+	auto pr2 = beg2.prange(last2);
+	auto prx2 = std::dynamic_pointer_cast<YRange>(pr2);
+
+	EXPECT_EQ(pr2->size(), pSize2);
+	EXPECT_EQ(prx2->size(), pSize2);
+	
+	const SizeT mmsize2 = lastJ2-begJ2+1;
+	auto mkm2 = [&](SizeT i) {
+	    return Vector<DType>({DType(i/mmsize2+begI2+begI),DType(mMeta[i % mmsize2+begJ2+begJ])}); };
+
+	for(auto i = prx2->begin(); i != prx2->end(); ++i){
+	    EXPECT_TRUE(*i == mkm2(i.lex()));
+	}
+	
     }
 
 // RCast_Test