diff --git a/include/sdsl/wt_int.hpp b/include/sdsl/wt_int.hpp
index 33911b8c9..db94c49a7 100644
--- a/include/sdsl/wt_int.hpp
+++ b/include/sdsl/wt_int.hpp
@@ -166,6 +166,7 @@ class wt_int
             init_buffers(m_max_level);
         };
 
+       
         //! Semi-external constructor
         /*! \param buf         File buffer of the int_vector for which the wt_int should be build.
          *  \param size        Size of the prefix of v, which should be indexed.
@@ -815,6 +816,40 @@ class wt_int
             return node_type(0, m_size, 0, 0);
         }
 
+        bool node_access(const node_type & v, size_type i) const {
+          size_type v_sp_pos  = v.offset;
+          return m_tree[v_sp_pos + i];
+        }
+
+        size_type
+        node_rank1(const node_type & v, size_type i) const {
+          // Get starting position rank
+          size_type v_sp_pos  = v.offset;
+          size_type v_sp_rank = m_tree_rank(v_sp_pos);
+          // TODO: BOUND CHECK: get node size by getting parents left and right children start positions (if any)
+          return m_tree_rank(v_sp_pos + i) - v_sp_rank;
+        }
+
+        size_type node_rank0(const node_type & v, size_type i) const {
+          return i - node_rank1(v, i);
+        }
+
+        size_type node_select1(const node_type &v, size_type i) const {
+          size_type v_sp_pos  = v.offset;
+          size_type v_sp_rank1 = m_tree_rank(v_sp_pos);
+          // TODO: BOUND CHECK: get node size by getting parents left and right children start positions (if any)
+          return m_tree_select1(i + v_sp_rank1) - v_sp_pos;
+        }
+
+        size_type node_select0(const node_type &v, size_type i) const {
+          size_type v_sp_pos  = v.offset;
+          size_type v_sp_rank0 = v_sp_pos - m_tree_rank(v_sp_pos);
+          // TODO: BOUND CHECK: get node size by getting parents left and right children start positions (if any)
+          return m_tree_select0(i + v_sp_rank0) - v_sp_pos;
+        }
+
+
+
         //! Returns the two child nodes of an inner node
         /*! \param v An inner node of a wavelet tree.
          *  \return Return an array of nodes (left child, right child).
diff --git a/include/sdsl/wt_pc.hpp b/include/sdsl/wt_pc.hpp
index 9d8fb1309..7b8e49ed0 100644
--- a/include/sdsl/wt_pc.hpp
+++ b/include/sdsl/wt_pc.hpp
@@ -807,6 +807,33 @@ class wt_pc
             return {ranges, std::move(res)};
         }
 
+        size_type
+        node_rank1(const node_type & v, size_type i) const {
+          // Get starting position rank
+          size_type v_sp_pos  = m_tree.bv_pos(v);
+          size_type v_sp_rank = m_tree.bv_pos_rank(v);
+          // TODO: BOUND CHECK: get node size by getting parents left and right children start positions (if any)
+          return m_bv_rank(v_sp_pos + i) - v_sp_rank;
+        }
+
+        size_type node_rank0(const node_type & v, size_type i) const {
+          return i - node_rank1(v, i);
+        }
+
+        size_type node_select1(const node_type &v, size_type i) const {
+          auto v_sp_pos   = m_tree.bv_pos(v);
+          auto v_sp_rank1 = m_tree.bv_pos_rank(v);
+          // TODO: BOUND CHECK: get node size by getting parents left and right children start positions (if any)
+          return m_bv_select1(i + v_sp_rank1) - v_sp_pos;
+        }
+
+        size_type node_select0(const node_type &v, size_type i) const {
+          auto v_sp_pos   = m_tree.bv_pos(v);
+          auto v_sp_rank0 = v_sp_pos - m_tree.bv_pos_rank(v);
+          // TODO: BOUND CHECK: get node size by getting parents left and right children start positions (if any)
+          return m_bv_select0(i + v_sp_rank0) - v_sp_pos;
+        }
+
         //! Returns for a range its left and right child ranges
         /*! \param v An inner node of an wavelet tree.
          *  \param r A ranges [s,e], such that [s,e] is