diff --git a/sapfor/experts/Sapfor_2017/_src/PrivateAnalyzer/private_arrays_search.cpp b/sapfor/experts/Sapfor_2017/_src/PrivateAnalyzer/private_arrays_search.cpp
index 4686eac..e6cab9e 100644
--- a/sapfor/experts/Sapfor_2017/_src/PrivateAnalyzer/private_arrays_search.cpp
+++ b/sapfor/experts/Sapfor_2017/_src/PrivateAnalyzer/private_arrays_search.cpp
@@ -249,7 +249,7 @@ vector<uint64_t> FindParticularSolution(const ArrayDimension& dim1, const ArrayD
     return {};
 }
 /* dim1 /\ dim2 */
-ArrayDimension* IntersectDimension(const ArrayDimension& dim1, const ArrayDimension& dim2) 
+ArrayDimension* DimensionIntersection(const ArrayDimension& dim1, const ArrayDimension& dim2) 
 {
     vector<uint64_t> partSolution =  FindParticularSolution(dim1, dim2);
     if (partSolution.empty()) 
@@ -281,10 +281,10 @@ ArrayDimension* IntersectDimension(const ArrayDimension& dim1, const ArrayDimens
 /* dim1 / dim2 */
 vector<ArrayDimension> DimensionDifference(const ArrayDimension& dim1, const ArrayDimension& dim2)
 {
-    ArrayDimension* intersection = IntersectDimension(dim1, dim2);
+    ArrayDimension* intersection = DimensionIntersection(dim1, dim2);
     if (!intersection) 
     {
-        return {dim1, dim2};
+        return {dim1};
     }
     vector<ArrayDimension> result;
     /* add the part before intersection */
@@ -321,6 +321,24 @@ vector<ArrayDimension> DimensionDifference(const ArrayDimension& dim1, const Arr
 }
 
 
+vector<ArrayDimension> DimensionUnion(const ArrayDimension& dim1, const ArrayDimension& dim2)
+{
+    vector<ArrayDimension> res;
+    ArrayDimension* inter = DimensionIntersection(dim1, dim2);
+    if(!inter)
+    {
+        return { dim1, dim2 };
+    }
+    res.push_back(*inter);
+    delete(inter);
+    vector<ArrayDimension> diff1, diff2;
+    diff1 = DimensionDifference(dim1, dim2);
+    diff2 = DimensionDifference(dim2, dim1);
+    res.insert(res.end(), diff1.begin(), diff1.end());
+    res.insert(res.end(), diff2.begin(), diff2.end());
+    return res;
+}
+
 void FindPrivateArrays(map<string, vector<LoopGraph*>> &loopGraph, map<FuncInfo*, vector<SAPFOR::BasicBlock*>>& FullIR)
 {  
     for (const auto& curr_graph_pair: loopGraph)