diff --git a/kokkos_tree/kokkos_core/README.md b/kokkos_tree/kokkos_core/README.md
new file mode 100644
index 0000000..e69de29
diff --git a/kokkos_tree/kokkos_core/View_data_analysis_kokkos_investigation.hpp b/kokkos_tree/kokkos_core/View_data_analysis_kokkos_investigation.hpp
new file mode 100644
index 0000000..4fca69e
--- /dev/null
+++ b/kokkos_tree/kokkos_core/View_data_analysis_kokkos_investigation.hpp
@@ -0,0 +1,57 @@
+#include <Kokkos_Core.hpp>
+#include <type_traits>
+//#include <View/Kokkos_ViewDataAnalysis.hpp>
+
+namespace Test{
+
+TEST(ViewDataType,ViewDataType_linefrom251){
+    static_assert(std::is_same_v<Kokkos::Impl::ViewDataType<double,Kokkos::Impl::ViewDimension<>>::type, double>, "ViewDataType<double,Kokkos::Impl::ViewDimension<>>::type should be double");
+    static_assert(std::is_same_v<Kokkos::Impl::ViewDataType<double,Kokkos::Impl::ViewDimension<0>>::type, double*>, "ViewDataType<double,Kokkos::Impl::ViewDimension<0>>::type should be double*");
+    static_assert(std::is_same_v<Kokkos::Impl::ViewDataType<double,Kokkos::Impl::ViewDimension<0,0>>::type, double**>, "ViewDataType<double,Kokkos::Impl::ViewDimension<0,0>>::type should be double**");
+    static_assert(std::is_same_v<Kokkos::Impl::ViewDataType<double,Kokkos::Impl::ViewDimension<0,0,5>>::type, double**[5]>, "ViewDataType<double,Kokkos::Impl::ViewDimension<0,0,5>>::type should be double**[5]");
+}
+TEST(ViewArrayAnalysis,ViewArrayAnalysis_line_289){
+    static_assert(std::is_same_v<Kokkos::Impl::ViewArrayAnalysis<double>::value_type, double>, "ViewArrayAnalysis<double>::value_type should be double");
+    static_assert(std::is_same_v<Kokkos::Impl::ViewArrayAnalysis<double>::const_value_type, const double>, "ViewArrayAnalysis<double>::const_value_type should be const double");
+    static_assert(std::is_same_v<Kokkos::Impl::ViewArrayAnalysis<const double>::non_const_value_type, double>, "ViewArrayAnalysis<const double>::non_const_value_type should be double");
+    static_assert(std::is_same_v<Kokkos::Impl::ViewArrayAnalysis<double>::static_dimension, Kokkos::Impl::ViewDimension<>>, "ViewArrayAnalysis<double>::static_dimension should be Kokkos::Impl::ViewDimension<>");
+    static_assert(std::is_same_v<Kokkos::Impl::ViewArrayAnalysis<double>::dynamic_dimension, Kokkos::Impl::ViewDimension<>>, "ViewArrayAnalysis<double>::dynamic_dimension should be Kokkos::Impl::ViewDimension<>");
+    static_assert(std::is_same_v<Kokkos::Impl::ViewArrayAnalysis<double>::dimension, Kokkos::Impl::ViewDimension<>>, "ViewArrayAnalysis<double>::dimension should be Kokkos::Impl::ViewDimension<>");
+    //static_assert(std::is_same_v<Kokkos::Impl::ViewArrayAnalysis<double[5]>::nested,Kokkos::Impl::ViewArrayAnalysis<double>>, "ViewArrayAnalysis<double[5]>::nested should be Kokkos::Impl::ViewArrayAnalysis<double>"); this is private can't invoke.
+    static_assert(std::is_same_v<Kokkos::Impl::ViewArrayAnalysis<double[5]>::value_type, double>, "ViewArrayAnalysis<double[5]>::value_type should be double");
+    static_assert(std::is_same_v<Kokkos::Impl::ViewArrayAnalysis<double[5]>::const_value_type, const double>, "ViewArrayAnalysis<double[5]>::const_value_type should be const double");
+    static_assert(std::is_same_v<Kokkos::Impl::ViewArrayAnalysis<double[5]>::non_const_value_type, double>, "ViewArrayAnalysis<double[5]>::non_const_value_type should be double");
+    static_assert(std::is_same_v<Kokkos::Impl::ViewArrayAnalysis<double[5]>::static_dimension, Kokkos::Impl::ViewDimension<5>>, "ViewArrayAnalysis<double[5]>::static_dimension should be Kokkos::Impl::ViewDimension<5>");
+    //static_assert(std::is_same_v<Kokkos::Impl::ViewArrayAnalysis<double[5]>::dynamic_dimension, Kokkos::Impl::ViewDimension<>>, "ViewArrayAnalysis<double[5]>::dynamic_dimension should be Kokkos::Impl::ViewDimension<>");
+    static_assert(Kokkos::Impl::ViewArrayAnalysis<double[5]>::static_dimension::ArgN0 == 5, "ViewArrayAnalysis<double[5]>::static_dimension::ArgN0 should be 5");
+    static_assert(std::is_same_v<Kokkos::Impl::ViewArrayAnalysis<double[5][4][6]>::value_type,double>, "ViewArrayAnalysis<double[5][4][6]>::value_type should bematch");
+    auto constexpr argn0 = Kokkos::Impl::ViewArrayAnalysis<double[5][4][6]>::static_dimension::ArgN0;
+    auto constexpr argn1 = Kokkos::Impl::ViewArrayAnalysis<double[5][4][6]>::static_dimension::ArgN1;
+    auto constexpr argn2 = Kokkos::Impl::ViewArrayAnalysis<double[5][4][6]>::static_dimension::ArgN2;
+    auto constexpr rank = Kokkos::Impl::ViewArrayAnalysis<double[5][4][6]>::static_dimension::rank;
+    auto constexpr rank_dyn = Kokkos::Impl::ViewArrayAnalysis<double[5][4][6]>::static_dimension::rank_dynamic;
+    std::cout<<"ArgN0 " <<argn0<<"\n";
+    std::cout<<"ArgN1 " <<argn1<<"\n";
+    std::cout<<"ArgN2 " <<argn2<<"\n";
+    std::cout<<"rank "<<rank<<"\n";
+    std::cout<<"rank_dun "<<rank_dyn<<"\n";
+    using vaa = Kokkos::Impl::ViewArrayAnalysis<double[]>;
+    auto constexpr dargn0 = vaa::dynamic_dimension::ArgN0;
+    std::cout<<"Dynamic argn0 "<<dargn0<<"\n";
+    std::cout<<"Dynamic rank = "<<vaa::dynamic_dimension::rank_dynamic<<"\n";
+    using mvaa = Kokkos::Impl::ViewArrayAnalysis<double[]>;
+    auto constexpr mdargn0 = mvaa::dynamic_dimension::ArgN0;
+    auto constexpr mdargn1 = mvaa::dynamic_dimension::ArgN1;
+    auto constexpr mdargn2 = mvaa::dynamic_dimension::ArgN2;
+    auto constexpr mdrank = mvaa::dynamic_dimension::rank;
+    auto constexpr mdrankdyn = mvaa::dynamic_dimension::rank_dynamic;
+    std::cout<<"mdArgN0 " <<mdargn0<<"\n";
+    std::cout<<"mdArgN1 " <<mdargn1<<"\n";
+    std::cout<<"mdArgN2 " <<mdargn2<<"\n";
+    std::cout<<"mdrank "<<mdrank<<"\n";
+    std::cout<<"drank_dyn "<<mdrankdyn<<"\n";
+    static_assert(std::is_same_v<Kokkos::Impl::ViewArrayAnalysis<double***>::dynamic_dimension,Kokkos::Impl::ViewDimension<0,0,0>>, "ViewArrayAnalysis<double***>::dynamic_dimension should be Kokkos::Impl::ViewDimension<0,0,0>");
+    static_assert(std::is_same_v<Kokkos::Impl::ViewArrayAnalysis<double***>::dynamic_dimension,Kokkos::Impl::ViewArrayAnalysis<double***>::dimension>, "ViewArrayAnalysis<double***>::dynamic_dimension should be Kokkos::Impl::ViewArrayAnalysis<double***>::dimension");
+
+}
+}
\ No newline at end of file
diff --git a/kokkos_tree/mdspan/README.md b/kokkos_tree/mdspan/README.md
new file mode 100644
index 0000000..e69de29
diff --git a/kokkos_tree/mdspan/kokkos_extent_inv.hpp b/kokkos_tree/mdspan/kokkos_extent_inv.hpp
new file mode 100644
index 0000000..4e563ca
--- /dev/null
+++ b/kokkos_tree/mdspan/kokkos_extent_inv.hpp
@@ -0,0 +1,43 @@
+#include <Kokkos_Core.hpp>
+
+
+using ext = MDSPAN_IMPL_STANDARD_NAMESPACE::extents<int, 2, 3, 4>;
+namespace Test {
+
+TEST(extent_inv, extent_line_376){
+    static_assert(std::is_same_v<typename ext::index_type,int>,"index_type is not int");
+    static_assert(std::is_same_v<typename ext::rank_type,size_t>,"rank_type is not size_t");
+    auto constexpr rank = ext::rank();
+    static_assert(rank == 3,"rank is not 3");
+    auto constexpr drank = ext::rank_dynamic();
+    static_assert(drank == 0,"dynamic rank is not 0");
+    using dext = MDSPAN_IMPL_STANDARD_NAMESPACE::extents<int, 2, MDSPAN_IMPL_STANDARD_NAMESPACE::dynamic_extent, 4>;
+    auto constexpr drank2 = dext::rank_dynamic();
+    static_assert(drank2 == 1,"dynamic rank is not 1");
+    using msa = MDSPAN_IMPL_STANDARD_NAMESPACE::detail::maybe_static_array<int, size_t, MDSPAN_IMPL_STANDARD_NAMESPACE::dynamic_extent,2,3,4,MDSPAN_IMPL_STANDARD_NAMESPACE::dynamic_extent,5>;
+    static_assert(std::is_same_v<msa::value_type,int>,"value_type is not int");
+    static_assert(std::is_same_v<msa::static_value_type,size_t>,"static_value_type is not size_t");
+    static_assert(msa::tag_value == MDSPAN_IMPL_STANDARD_NAMESPACE::dynamic_extent,"tag_value is not dynamic_extent");
+    msa m1(23);
+    std::array<size_t,1> d_rank = {4};
+    msa m2(d_rank);
+    auto m1_static = m1.static_value(0);
+    EXPECT_EQ(m1_static,2);
+    auto m2_dynamic = m2.value(3);
+    std::cout<<"m2_dynamic: "<<m2_dynamic<<std::endl;
+    std::cout<<"m1 size : "<<m1.size()<<std::endl;
+}
+TEST(extent_inv, extent_line_main376){
+    using extent = MDSPAN_IMPL_STANDARD_NAMESPACE::extents<int, 2, 3, 4, MDSPAN_IMPL_STANDARD_NAMESPACE::dynamic_extent>;
+    static_assert(extent::rank() == 4,"rank is not 4");
+    static_assert(extent::rank_dynamic() == 1,"dynamic rank is not 1");
+    //static_assert(extent::extent(0) == 2,"extent(0) is not 2");
+    ///static_assert(extent::extent(3) == 0,"extent(3) is not 3"); as non static;
+    extent ex;
+    EXPECT_EQ(ex.extent(0),2);
+    EXPECT_EQ(ex.extent(1),3);
+    EXPECT_EQ(ex.extent(2),4);
+    EXPECT_EQ(ex.extent(3),0);
+    static_assert(extent::static_extent(0) == 2,"extent(0) is not 2");
+}
+}
\ No newline at end of file
diff --git a/kokkos_tree/test_dyn_rank.cpp b/kokkos_tree/test_dyn_rank.cpp
index bd3afae..54965f8 100644
--- a/kokkos_tree/test_dyn_rank.cpp
+++ b/kokkos_tree/test_dyn_rank.cpp
@@ -2,6 +2,8 @@
 #include "kokkos_core/kokkos_pair_investigation.hpp"
 #include "mdspan/kokkos_raw_mdspan.hpp"
 #include "kokkos_core/test_drank.hpp"
+#include "kokkos_core/View_data_analysis_kokkos_investigation.hpp"
+#include "mdspan/kokkos_extent_inv.hpp"
 #include <Kokkos_Core.hpp>
 #include <gtest/gtest.h>
 int main(int argc, char **argv) {