diff --git a/CMakeLists.txt b/CMakeLists.txt
index 49b8680..a7b1de8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,5 +1,5 @@
 cmake_minimum_required(VERSION 3.25)
-project(blt-gp VERSION 0.0.21)
+project(blt-gp VERSION 0.0.22)
 
 option(ENABLE_ADDRSAN "Enable the address sanitizer" OFF)
 option(ENABLE_UBSAN "Enable the ub sanitizer" OFF)
diff --git a/examples/main.cpp b/examples/main.cpp
index e62ae4e..4e2959b 100644
--- a/examples/main.cpp
+++ b/examples/main.cpp
@@ -78,39 +78,39 @@ void test()
 {
     std::vector<op> operations;
     std::vector<float> values;
-
+    
     std::stack<op> tree_generator;
     tree_generator.push(generate_op());
-
+    
     while (!tree_generator.empty())
     {
         auto opn = tree_generator.top();
         tree_generator.pop();
-
+        
         operations.push_back(opn);
         if (opn == op::LIT)
         {
             values.push_back(random_value());
             continue;
         }
-
+        
         // child 1
         if (choice())
             tree_generator.push(generate_op());
         else
             tree_generator.push(op::LIT);
-
+        
         // child 2
         if (choice())
             tree_generator.push(generate_op());
         else
             tree_generator.push(op::LIT);
     }
-
+    
     for (const auto& v : operations)
         std::cout << to_string(v) << " ";
     std::cout << std::endl;
-
+    
     {
         std::stack<blt::size_t> process;
         for (const auto& v : operations)
@@ -160,11 +160,11 @@ void test()
         }
         std::cout << std::endl;
     }
-
+    
     for (const auto& v : values)
         std::cout << v << " ";
     std::cout << std::endl;
-
+    
     {
         std::stack<blt::size_t> process;
         blt::size_t index = 0;
@@ -184,7 +184,7 @@ void test()
                     std::cout << values[index++];
                     break;
             }
-
+            
             while (!process.empty())
             {
                 auto top = process.top();
@@ -217,13 +217,13 @@ void test()
         }
         std::cout << std::endl;
     }
-
+    
     std::stack<float> process;
     std::stack<op> operators;
-
+    
     for (const auto& v : operations)
         operators.push(v);
-
+    
     while (!operators.empty())
     {
         auto oper = operators.top();
@@ -265,10 +265,10 @@ void test()
             std::cout << "\tresult: " << values.back() << std::endl;
         }
     }
-
+    
     std::cout << process.size() << std::endl;
     std::cout << process.top() << std::endl;
-
+    
 }
 //
 //struct silly
@@ -293,15 +293,21 @@ void test()
 //    unsigned char data[9582];
 //};
 
-blt::gp::stack_allocator alloc;
+blt::gp::type_system type_system;
+blt::gp::gp_program program(type_system);
+
+blt::gp::operation_t<float(float, float)> add([](float a, float b) { return a + b; });
+blt::gp::operation_t<float(float, float)> sub([](float a, float b) { return a - b; });
+blt::gp::operation_t<float(float, float)> mul([](float a, float b) { return a * b; });
+blt::gp::operation_t<float(float, float)> pro_div([](float a, float b) { return b == 0 ? 0.0f : a / b; });
+blt::gp::operation_t<float()> lit([]() {return 0.0f;});
 
-float nyah(float f, int i, bool b)
-{
-    return f + static_cast<float>(i * b);
-}
 
 int main()
 {
+    type_system.register_type<float>();
+    type_system.register_type<bool>();
+
 //    constexpr blt::size_t MAX_ALIGNMENT = 8;
 //    test();
 //    std::cout << alignof(silly) << " " << sizeof(silly) << std::endl;
@@ -364,18 +370,18 @@ int main()
 //    alloc.push(550.3f);
 //    alloc.push(20.1230345);
 //    alloc.push(std::string("SillyString"));
-    alloc.push(33.22f);
-    alloc.push(120);
-    alloc.push(true);
-    
-    blt::gp::operation_t<float(float, int, bool)> silly_op(nyah);
-    blt::gp::operation_t<float(float, float)> silly_op_2([](float f, float g) {
-        return f + g;
-    });
-    
-    std::cout << silly_op(alloc) << std::endl;
-    
-    std::cout << "Is empty? " << alloc.empty() << std::endl;
+//    alloc.push(33.22f);
+//    alloc.push(120);
+//    alloc.push(true);
+//
+//    blt::gp::operation_t<float(float, int, bool)> silly_op(nyah);
+//    blt::gp::operation_t<float(float, float)> silly_op_2([](float f, float g) {
+//        return f + g;
+//    });
+
+//    std::cout << silly_op(alloc) << std::endl;
+//
+//    std::cout << "Is empty? " << alloc.empty() << std::endl;
 
 //    std::cout << std::endl;
 //
diff --git a/include/blt/gp/program.h b/include/blt/gp/program.h
index ae3a3ec..3cf3a11 100644
--- a/include/blt/gp/program.h
+++ b/include/blt/gp/program.h
@@ -19,28 +19,58 @@
 #ifndef BLT_GP_PROGRAM_H
 #define BLT_GP_PROGRAM_H
 
-#include <blt/gp/stack.h>
+
 #include <cstddef>
-#include <blt/gp/fwdecl.h>
 #include <functional>
-#include <blt/std/ranges.h>
-#include <blt/std/hashmap.h>
-#include <blt/std/types.h>
-#include <blt/std/utility.h>
 #include <type_traits>
 #include <string_view>
 #include <string>
 #include <utility>
 #include <iostream>
+#include <random>
+#include <blt/std/ranges.h>
+#include <blt/std/hashmap.h>
+#include <blt/std/types.h>
+#include <blt/std/utility.h>
+#include <blt/std/memory.h>
+#include <blt/gp/fwdecl.h>
+#include <blt/gp/stack.h>
 
 namespace blt::gp
 {
+    template<typename T>
+    struct integer_type
+    {
+        T id;
+        
+        integer_type() = default;
+        
+        integer_type(T id): id(id) // NOLINT
+        {}
+        
+        inline operator T() const // NOLINT
+        {
+            return id;
+        }
+    };
+    
+    struct operator_id : integer_type<blt::size_t>
+    {
+        using integer_type<blt::size_t>::integer_type;
+    };
+    
+    struct type_id : integer_type<blt::size_t>
+    {
+        using integer_type<blt::size_t>::integer_type;
+    };
     
     class type
     {
         public:
+            type() = default;
+            
             template<typename T>
-            static type make_type(blt::size_t id)
+            static type make_type(type_id id)
             {
                 return type(sizeof(T), id, blt::type_string<T>());
             }
@@ -50,7 +80,7 @@ namespace blt::gp
                 return size_;
             }
             
-            [[nodiscard]] blt::size_t id() const
+            [[nodiscard]] type_id id() const
             {
                 return id_;
             }
@@ -61,12 +91,19 @@ namespace blt::gp
             }
         
         private:
-            type(size_t size, size_t id, std::string_view name): size_(size), id_(id), name_(name)
+            type(size_t size, type_id id, std::string_view name): size_(size), id_(id), name_(name)
             {}
             
-            blt::size_t size_;
-            blt::size_t id_;
-            std::string name_;
+            blt::size_t size_{};
+            type_id id_{};
+            std::string name_{};
+    };
+    
+    class allowed_types_t
+    {
+        public:
+        
+        private:
     };
     
     class type_system
@@ -77,7 +114,7 @@ namespace blt::gp
             template<typename T>
             inline type register_type()
             {
-                types[blt::type_string_raw<T>()](type::make_type<T>(types.size()));
+                types.insert({blt::type_string_raw<T>(), type::make_type<T>(types.size())});
                 return types[blt::type_string_raw<T>()];
             }
             
@@ -167,27 +204,24 @@ namespace blt::gp
             template<typename Return, typename... Args>
             void add_operator(const operation_t<Return(Args...)>& op)
             {
-                if (op.get_argc() == 0)
-                    terminals.push_back(operators.size());
-                else
-                    non_terminals.push_back(operators.size());
+                auto return_type_id = system.get_type<Return>().id();
+                auto& operator_list = op.get_argc() == 0 ? terminals : non_terminals;
+                operator_list[return_type_id].push_back(operators.size());
                 
+                auto operator_index = operators.size();
+                (argument_types[operator_index].push_back(system.get_type<Args>()), ...);
                 operators.push_back(op.make_callable());
-                
-                std::vector<type> types;
-                (types.push_back(system.get_type<Args>()), ...);
-                arg_types.push_back(std::move(types));
-                
-                return_types.push_back(system.get_type<Return>());
             }
         
         private:
             type_system system;
+            blt::gp::stack_allocator alloc;
+            // indexed from return TYPE ID, returns index of operator
+            blt::expanding_buffer<std::vector<blt::size_t>> terminals;
+            blt::expanding_buffer<std::vector<blt::size_t>> non_terminals;
+            // indexed from OPERATOR NUMBER
+            blt::expanding_buffer<std::vector<type>> argument_types;
             std::vector<std::function<void(stack_allocator&)>> operators;
-            std::vector<blt::size_t> terminals;
-            std::vector<blt::size_t> non_terminals;
-            std::vector<type> return_types;
-            std::vector<std::vector<type>> arg_types;
     };
     
 }
diff --git a/lib/blt b/lib/blt
index 2266d64..9ad9619 160000
--- a/lib/blt
+++ b/lib/blt
@@ -1 +1 @@
-Subproject commit 2266d64f042bc97b54e7e50dcaac730bcc3ab4c3
+Subproject commit 9ad96191ff91ec7efa6aa142e377201fe81b4c40
diff --git a/src/gp.cpp b/src/gp.cpp
index 8c72729..2a53a88 100644
--- a/src/gp.cpp
+++ b/src/gp.cpp
@@ -14,4 +14,4 @@
  *
  *  You should have received a copy of the GNU General Public License
  *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
+ */
\ No newline at end of file