diff --git a/.idea/codeStyles/codeStyleConfig.xml b/.idea/codeStyles/codeStyleConfig.xml
new file mode 100644
index 0000000..f63addd
--- /dev/null
+++ b/.idea/codeStyles/codeStyleConfig.xml
@@ -0,0 +1,5 @@
+<component name="ProjectCodeStyleConfiguration">
+  <state>
+    <option name="PREFERRED_PROJECT_CODE_STYLE" value="Brett C++ Config 2" />
+  </state>
+</component>
\ No newline at end of file
diff --git a/.idea/editor.xml b/.idea/editor.xml
new file mode 100644
index 0000000..46540da
--- /dev/null
+++ b/.idea/editor.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="BackendCodeEditorSettings">
+    <option name="/Default/Housekeeping/GlobalSettingsUpgraded/IsUpgraded/@EntryValue" value="true" type="bool" />
+  </component>
+</project>
\ No newline at end of file
diff --git a/.idea/misc.xml b/.idea/misc.xml
index 79b3c94..0b76fe5 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,4 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
+  <component name="CMakePythonSetting">
+    <option name="pythonIntegrationState" value="YES" />
+  </component>
   <component name="CMakeWorkspace" PROJECT_DIR="$PROJECT_DIR$" />
 </project>
\ No newline at end of file
diff --git a/CMakeLists.txt b/CMakeLists.txt
index a990085..7389c4f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,5 +1,5 @@
 cmake_minimum_required(VERSION 3.25)
-project(blt-gp VERSION 0.1.56)
+project(blt-gp VERSION 0.2.1)
 
 include(CTest)
 
diff --git a/examples/rice_classification.cpp b/examples/rice_classification.cpp
index 181aa02..71b7ec8 100644
--- a/examples/rice_classification.cpp
+++ b/examples/rice_classification.cpp
@@ -22,7 +22,7 @@
 #include <blt/profiling/profiler_v2.h>
 #include <blt/gp/tree.h>
 #include <blt/std/logging.h>
-#include <blt/std/format.h>
+#include <blt/format/format.h>
 #include <blt/parse/argparse.h>
 #include <iostream>
 #include "operations_common.h"
@@ -99,7 +99,7 @@ blt::gp::operation_t op_extent([](const rice_record& rice_data) {
 constexpr auto fitness_function = [](blt::gp::tree_t& current_tree, blt::gp::fitness_t& fitness, blt::size_t) {
     for (auto& training_case : training_cases)
     {
-        auto v = current_tree.get_evaluation_value<float>(&training_case);
+        auto v = current_tree.get_evaluation_value<float>(training_case);
         switch (training_case.type)
         {
             case rice_type_t::Cammeo:
@@ -209,7 +209,7 @@ test_results_t test_individual(blt::gp::individual_t& i)
     
     for (auto& testing_case : testing_cases)
     {
-        auto result = i.tree.get_evaluation_value<float>(&testing_case);
+        auto result = i.tree.get_evaluation_value<float>(testing_case);
         switch (testing_case.type)
         {
             case rice_type_t::Cammeo:
diff --git a/include/blt/gp/tree.h b/include/blt/gp/tree.h
index 7e3e0e2..e35ebd4 100644
--- a/include/blt/gp/tree.h
+++ b/include/blt/gp/tree.h
@@ -116,12 +116,17 @@ namespace blt::gp
                 return values;
             }
             
-            template<typename T, std::enable_if_t<!std::is_pointer_v<T>, bool> = true>
+            template<typename T, std::enable_if_t<!(std::is_pointer_v<T> || std::is_null_pointer_v<T>), bool> = true>
             [[nodiscard]] evaluation_context& evaluate(const T& context) const
             {
                 return (*func)(*this, const_cast<void*>(static_cast<const void*>(&context)));
             }
             
+            [[nodiscard]] evaluation_context& evaluate() const
+            {
+                return (*func)(*this, nullptr);
+            }
+            
             blt::size_t get_depth(gp_program& program);
             
             /**
@@ -151,6 +156,12 @@ namespace blt::gp
                 return evaluate(context).values.template pop<T>();
             }
             
+            template<typename T>
+            T get_evaluation_value()
+            {
+                return evaluate().values.pop<T>();
+            }
+            
             void print(gp_program& program, std::ostream& output, bool print_literals = true, bool pretty_indent = false,
                        bool include_types = false) const;
             
diff --git a/src/transformers.cpp b/src/transformers.cpp
index a50778f..efdee82 100644
--- a/src/transformers.cpp
+++ b/src/transformers.cpp
@@ -81,9 +81,11 @@ namespace blt::gp
         c1_operators.clear();
         c2_operators.clear();
         
+        // TODO: more crossover!
         switch (selection)
         {
             case 0:
+            case 1:
             {
                 // basic crossover
                 auto crossover_point_begin_itr = c1_ops.begin() + point->p1_crossover_point;
@@ -136,9 +138,6 @@ namespace blt::gp
                 c2_ops.insert(++insert_point_c2, c1_operators.begin(), c1_operators.end());
             }
                 break;
-            case 1: {
-            
-            }
                 break;
             default:
 #if BLT_DEBUG_LEVEL > 0
diff --git a/tests/evaluation_tests.cpp b/tests/evaluation_tests.cpp
index fb6c524..e368b6a 100644
--- a/tests/evaluation_tests.cpp
+++ b/tests/evaluation_tests.cpp
@@ -22,7 +22,7 @@
 #include <blt/gp/program.h>
 #include <random>
 
-const blt::u64 SEED = std::random_device()();
+static const auto SEED_FUNC = [] { return std::random_device()(); };
 
 struct large_256
 {
@@ -52,13 +52,12 @@ struct large_18290
 
 large_18290 base{};
 
-blt::gp::type_provider type_system;
-blt::gp::gp_program program{type_system, SEED};
+blt::gp::gp_program program{SEED_FUNC};
 
 blt::gp::op_container_t make_container(blt::gp::operator_id id)
 {
     auto& info = program.get_operator_info(id);
-    return {type_system.get_type(info.return_type).size(), id, false};
+    return {program.get_typesystem().get_type(info.return_type).size(), id, false};
 }
 
 blt::gp::op_container_t make_value(const blt::gp::type& id)
@@ -107,12 +106,12 @@ void basic_tree()
     blt::gp::tree_t tree{program};
     
     tree.get_operations().push_back(make_container(sub.id));
-    tree.get_operations().push_back(make_value(type_system.get_type<float>()));
-    tree.get_operations().push_back(make_value(type_system.get_type<float>()));
+    tree.get_operations().push_back(make_value(program.get_typesystem().get_type<float>()));
+    tree.get_operations().push_back(make_value(program.get_typesystem().get_type<float>()));
     tree.get_values().push(50.0f);
     tree.get_values().push(120.0f);
     
-    auto val = tree.get_evaluation_value<float>(nullptr);
+    auto val = tree.get_evaluation_value<float>();
     BLT_TRACE(val);
     BLT_ASSERT(val == (120 - 50));
 }
@@ -125,16 +124,16 @@ void large_cross_type_tree()
     
     ops.push_back(make_container(cross_large_type.id));
     ops.push_back(make_container(sub.id));
-    ops.push_back(make_value(type_system.get_type<float>()));
-    ops.push_back(make_value(type_system.get_type<float>()));
-    ops.push_back(make_value(type_system.get_type<float>()));
+    ops.push_back(make_value(program.get_typesystem().get_type<float>()));
+    ops.push_back(make_value(program.get_typesystem().get_type<float>()));
+    ops.push_back(make_value(program.get_typesystem().get_type<float>()));
     ops.push_back(make_container(large_literal.id));
     
     vals.push(50.0f);
     vals.push(120.0f);
     vals.push(5555.0f);
     
-    auto val = tree.get_evaluation_value<large_18290>(nullptr);
+    auto val = tree.get_evaluation_value<large_18290>();
     blt::black_box(val);
 }
 
@@ -143,11 +142,7 @@ int main()
     for (auto& v : base.data)
         v = static_cast<blt::u8>(blt::random::murmur_random64c(691, std::numeric_limits<blt::u8>::min(), std::numeric_limits<blt::u8>::max()));
     
-    type_system.register_type<float>();
-    type_system.register_type<bool>();
-    type_system.register_type<large_18290>();
-    
-    blt::gp::operator_builder builder{type_system};
+    blt::gp::operator_builder builder{};
     program.set_operations(builder.build(f_literal, b_literal, add, basic_2t, sub, large_literal, cross_large_type));
     
     basic_tree();
diff --git a/tests/gp_test_1.cpp b/tests/gp_test_1.cpp
index 6d2c7cb..3a905da 100644
--- a/tests/gp_test_1.cpp
+++ b/tests/gp_test_1.cpp
@@ -438,9 +438,7 @@ int main()
         return ctx.x;
     });
     
-    blt::gp::type_provider system;
-    system.register_type<float>();
-    blt::gp::operator_builder<context> ops{system};
+    blt::gp::operator_builder<context> ops{};
     
     //BLT_TRACE(blt::type_string<decltype(silly_op_3)::first::type>());
     //BLT_TRACE(typeid(decltype(silly_op_3)::first::type).name());
diff --git a/tests/gp_test_2.cpp b/tests/gp_test_2.cpp
index 960d414..6e439dc 100644
--- a/tests/gp_test_2.cpp
+++ b/tests/gp_test_2.cpp
@@ -21,10 +21,9 @@
 #include <blt/std/logging.h>
 
 
-static constexpr long SEED = 41912;
+static const auto SEED_FUNC = [] { return std::random_device()(); };
 
-blt::gp::type_provider type_system;
-blt::gp::gp_program program(type_system, SEED); // NOLINT
+blt::gp::gp_program program(SEED_FUNC); // NOLINT
 
 blt::gp::operation_t add([](float a, float b) {
     BLT_TRACE("a: %f + b: %f = %f", a, b, a + b);
@@ -53,16 +52,15 @@ auto lit = blt::gp::operation_t([]() {
  */
 int main()
 {
-    type_system.register_type<float>();
-    
-    blt::gp::operator_builder silly{type_system};
+    blt::gp::operator_builder silly{};
     
     program.set_operations(silly.build(add, sub, mul, pro_div, lit));
     
     blt::gp::grow_generator_t grow;
-    auto tree = grow.generate(blt::gp::generator_arguments{program, type_system.get_type<float>().id(), 3, 7});
+    blt::gp::tree_t tree{program};
+    grow.generate(tree, blt::gp::generator_arguments{program, program.get_typesystem().get_type<float>().id(), 3, 7});
     
-    auto value = tree.get_evaluation_value<float>(nullptr);
+    auto value = tree.get_evaluation_value<float>();
     
     BLT_TRACE(value);
     
diff --git a/tests/gp_test_3.cpp b/tests/gp_test_3.cpp
index d961b3d..820f928 100644
--- a/tests/gp_test_3.cpp
+++ b/tests/gp_test_3.cpp
@@ -20,10 +20,9 @@
 #include <blt/gp/tree.h>
 #include <blt/std/logging.h>
 
-static constexpr long SEED = 41912;
+static const auto SEED_FUNC = [] { return std::random_device()(); };
 
-blt::gp::type_provider type_system;
-blt::gp::gp_program program(type_system, SEED); // NOLINT
+blt::gp::gp_program program(SEED_FUNC); // NOLINT
 
 blt::gp::operation_t add([](float a, float b) { return a + b; });
 blt::gp::operation_t sub([](float a, float b) { return a - b; });
@@ -51,16 +50,14 @@ auto lit = blt::gp::operation_t([]() {
  */
 int main()
 {
-    type_system.register_type<float>();
-    type_system.register_type<bool>();
-    
-    blt::gp::operator_builder silly{type_system};
+    blt::gp::operator_builder silly{};
     program.set_operations(silly.build(add, sub, mul, pro_div, op_if, eq_f, eq_b, lt, gt, op_and, op_or, op_xor, op_not, lit));
     
     blt::gp::grow_generator_t grow;
-    auto tree = grow.generate(blt::gp::generator_arguments{program, type_system.get_type<float>().id(), 3, 7});
+    blt::gp::tree_t tree{program};
+    grow.generate(tree, blt::gp::generator_arguments{program, program.get_typesystem().get_type<float>().id(), 3, 7});
     
-    auto value = tree.get_evaluation_value<float>(nullptr);
+    auto value = tree.get_evaluation_value<float>();
     
     BLT_TRACE(value);
     
diff --git a/tests/gp_test_4.cpp b/tests/gp_test_4.cpp
index 585585d..3410cdd 100644
--- a/tests/gp_test_4.cpp
+++ b/tests/gp_test_4.cpp
@@ -20,10 +20,9 @@
 #include <blt/gp/tree.h>
 #include <blt/std/logging.h>
 
-static constexpr long SEED = 41912;
+static const auto SEED_FUNC = [] { return std::random_device()(); };
 
-blt::gp::type_provider type_system;
-blt::gp::gp_program program(type_system, SEED); // NOLINT
+blt::gp::gp_program program(SEED_FUNC); // NOLINT
 
 blt::gp::operation_t add([](float a, float b) { return a + b; });
 blt::gp::operation_t sub([](float a, float b) { return a - b; });
@@ -51,19 +50,16 @@ auto lit = blt::gp::operation_t([]() {
  */
 int main()
 {
-    type_system.register_type<float>();
-    type_system.register_type<bool>();
-    
-    blt::gp::operator_builder builder{type_system};
+    blt::gp::operator_builder builder{};
     program.set_operations(builder.build(add, sub, mul, pro_div, op_if, eq_f, eq_b, lt, gt, op_and, op_or, op_xor, op_not, lit));
     
     blt::gp::ramped_half_initializer_t pop_init;
     
-    auto pop = pop_init.generate(blt::gp::initializer_arguments{program, type_system.get_type<float>().id(), 500, 3, 10});
+    auto pop = pop_init.generate(blt::gp::initializer_arguments{program, program.get_typesystem().get_type<float>().id(), 500, 3, 10});
     
     for (auto& tree : pop.for_each_tree())
     {
-        auto value = tree.get_evaluation_value<float>(nullptr);
+        auto value = tree.get_evaluation_value<float>();
         
         BLT_TRACE(value);
     }
diff --git a/tests/gp_test_5.cpp b/tests/gp_test_5.cpp
index 7ef9e7a..ad077c8 100644
--- a/tests/gp_test_5.cpp
+++ b/tests/gp_test_5.cpp
@@ -40,11 +40,9 @@
 #include <string_view>
 #include <iostream>
 
-static constexpr long SEED = 41912;
+static const auto SEED_FUNC = [] { return std::random_device()(); };
 
-
-blt::gp::type_provider type_system;
-blt::gp::gp_program program(type_system, SEED); // NOLINT
+blt::gp::gp_program program(SEED_FUNC); // NOLINT
 
 blt::gp::operation_t add([](float a, float b) { return a + b; }, "add"); // 0
 blt::gp::operation_t sub([](float a, float b) { return a - b; }, "sub"); // 1
@@ -72,15 +70,12 @@ auto lit = blt::gp::operation_t([]() {
  */
 int main()
 {
-    type_system.register_type<float>();
-    type_system.register_type<bool>();
-    
-    blt::gp::operator_builder builder{type_system};
+    blt::gp::operator_builder builder{};
     program.set_operations(builder.build(add, sub, mul, pro_div, op_if, eq_f, eq_b, lt, gt, op_and, op_or, op_xor, op_not, lit));
     
     blt::gp::ramped_half_initializer_t pop_init;
     
-    auto pop = pop_init.generate(blt::gp::initializer_arguments{program, type_system.get_type<float>().id(), 500, 3, 10});
+    auto pop = pop_init.generate(blt::gp::initializer_arguments{program, program.get_typesystem().get_type<float>().id(), 500, 3, 10});
 
 //    for (auto& tree : pop.getIndividuals())
 //    {
@@ -99,7 +94,7 @@ int main()
     BLT_INFO("Pre-Crossover:");
     for (auto& tree : pop.get_individuals())
     {
-        auto f = tree.tree.get_evaluation_value<float>(nullptr);
+        auto f = tree.tree.get_evaluation_value<float>();
         pre.push_back(f);
         BLT_TRACE(f);
     }
@@ -116,34 +111,31 @@ int main()
             second = random.get_size_t(0ul, pop.get_individuals().size());
         } while (second == first);
         
-        auto results = crossover.apply(program, ind[first].tree, ind[second].tree);
-        if (results.has_value())
+        blt::gp::tree_t child1{program};
+        blt::gp::tree_t child2{program};
+        // crossover function assumes that children have been copied from parents
+        child1.copy_fast(ind[first].tree);
+        child2.copy_fast(ind[second].tree);
+        auto results = crossover.apply(program, ind[first].tree, ind[second].tree, child1, child2);
+        if (results)
         {
 //            bool print_literals = true;
 //            bool pretty_print = false;
 //            bool print_returns = false;
-//            BLT_TRACE("Parent 1: %f", ind[0].get_evaluation_value<float>(nullptr));
+//            BLT_TRACE("Parent 1: %f", ind[0].get_evaluation_value<float>());
 //            ind[0].print(program, std::cout, print_literals, pretty_print, print_returns);
-//            BLT_TRACE("Parent 2: %f", ind[1].get_evaluation_value<float>(nullptr));
+//            BLT_TRACE("Parent 2: %f", ind[1].get_evaluation_value<float>());
 //            ind[1].print(program, std::cout, print_literals, pretty_print, print_returns);
 //            BLT_TRACE("------------");
-//            BLT_TRACE("Child 1: %f", results->child1.get_evaluation_value<float>(nullptr));
+//            BLT_TRACE("Child 1: %f", results->child1.get_evaluation_value<float>());
 //            results->child1.print(program, std::cout, print_literals, pretty_print, print_returns);
-//            BLT_TRACE("Child 2: %f", results->child2.get_evaluation_value<float>(nullptr));
+//            BLT_TRACE("Child 2: %f", results->child2.get_evaluation_value<float>());
 //            results->child2.print(program, std::cout, print_literals, pretty_print, print_returns);
-            new_pop.get_individuals().emplace_back(std::move(results->child1));
-            new_pop.get_individuals().emplace_back(std::move(results->child2));
+            new_pop.get_individuals().emplace_back(std::move(child1));
+            new_pop.get_individuals().emplace_back(std::move(child2));
         } else
         {
-            switch (results.error())
-            {
-                case blt::gp::crossover_t::error_t::NO_VALID_TYPE:
-                    BLT_DEBUG("No valid type!");
-                    break;
-                case blt::gp::crossover_t::error_t::TREE_TOO_SMALL:
-                    BLT_DEBUG("Tree is too small!");
-                    break;
-            }
+            BLT_DEBUG("Crossover Failed.");
             errors++;
             new_pop.get_individuals().push_back(ind[first]);
             new_pop.get_individuals().push_back(ind[second]);
@@ -153,7 +145,7 @@ int main()
     BLT_INFO("Post-Crossover:");
     for (auto& tree : new_pop.for_each_tree())
     {
-        auto f = tree.get_evaluation_value<float>(nullptr);
+        auto f = tree.get_evaluation_value<float>();
         pos.push_back(f);
         BLT_TRACE(f);
     }
diff --git a/tests/gp_test_6.cpp b/tests/gp_test_6.cpp
index a3955e6..4be7b28 100644
--- a/tests/gp_test_6.cpp
+++ b/tests/gp_test_6.cpp
@@ -38,11 +38,9 @@
 #include <blt/std/logging.h>
 #include <blt/gp/transformers.h>
 
-static constexpr long SEED = 41912;
+static const auto SEED_FUNC = [] { return std::random_device()(); };
 
-
-blt::gp::type_provider type_system;
-blt::gp::gp_program program(type_system, SEED); // NOLINT
+blt::gp::gp_program program(SEED_FUNC); // NOLINT
 
 blt::gp::operation_t add([](float a, float b) { return a + b; }, "add"); // 0
 blt::gp::operation_t sub([](float a, float b) { return a - b; }, "sub"); // 1
@@ -70,15 +68,12 @@ auto lit = blt::gp::operation_t([]() {
  */
 int main()
 {
-    type_system.register_type<float>();
-    type_system.register_type<bool>();
-    
-    blt::gp::operator_builder builder{type_system};
+    blt::gp::operator_builder builder{};
     program.set_operations(builder.build(add, sub, mul, pro_div, op_if, eq_f, eq_b, lt, gt, op_and, op_or, op_xor, op_not, lit));
     
     blt::gp::ramped_half_initializer_t pop_init;
     
-    auto pop = pop_init.generate(blt::gp::initializer_arguments{program, type_system.get_type<float>().id(), 500, 3, 10});
+    auto pop = pop_init.generate(blt::gp::initializer_arguments{program, program.get_typesystem().get_type<float>().id(), 500, 3, 10});
     
     blt::gp::population_t new_pop;
     blt::gp::mutation_t mutator;
@@ -90,19 +85,22 @@ int main()
     BLT_INFO("Pre-Mutation:");
     for (auto& tree : pop.for_each_tree())
     {
-        auto f = tree.get_evaluation_value<float>(nullptr);
+        auto f = tree.get_evaluation_value<float>();
         pre.push_back(f);
         BLT_TRACE(f);
     }
     BLT_INFO("Mutation:");
     for (auto& tree : pop.for_each_tree())
     {
-        new_pop.get_individuals().emplace_back(mutator.apply(program, tree));
+        blt::gp::tree_t tree_out{program};
+        tree_out.copy_fast(tree);
+        mutator.apply(program, tree, tree_out);
+        new_pop.get_individuals().emplace_back(std::move(tree_out));
     }
     BLT_INFO("Post-Mutation");
     for (auto& tree : new_pop.for_each_tree())
     {
-        auto f = tree.get_evaluation_value<float>(nullptr);
+        auto f = tree.get_evaluation_value<float>();
         pos.push_back(f);
         BLT_TRACE(f);
     }
diff --git a/tests/gp_test_7.cpp b/tests/gp_test_7.cpp
index 25e9ad1..183256e 100644
--- a/tests/gp_test_7.cpp
+++ b/tests/gp_test_7.cpp
@@ -19,12 +19,11 @@
 #include <blt/gp/tree.h>
 #include <blt/std/logging.h>
 
-static constexpr long SEED = 41912;
+static const auto SEED_FUNC = [] { return std::random_device()(); };
 
 blt::gp::prog_config_t config = blt::gp::prog_config_t().set_elite_count(2);
 
-blt::gp::type_provider type_system;
-blt::gp::gp_program program(type_system, SEED, config); // NOLINT
+blt::gp::gp_program program(SEED_FUNC, config); // NOLINT
 std::array<float, 500> result_container;
 
 blt::gp::operation_t add([](float a, float b) { return a + b; }, "add"); // 0
@@ -59,7 +58,7 @@ void print_best()
         auto& tree = v.tree;
         auto size = tree.get_values().size();
         BLT_TRACE("%lf [index %ld] (fitness: %lf, raw: %lf) (depth: %ld) (size: t: %ld u: %ld r: %ld) filled: %f%%",
-                  tree.get_evaluation_value<float>(nullptr), i, v.fitness.adjusted_fitness, v.fitness.raw_fitness,
+                  tree.get_evaluation_value<float>(), i, v.fitness.adjusted_fitness, v.fitness.raw_fitness,
                   tree.get_depth(program), size.total_size_bytes, size.total_used_bytes,
                   size.total_remaining_bytes,
                   static_cast<double>(size.total_used_bytes) / (size.total_size_bytes == 0 ? 1 : static_cast<double>(size.total_size_bytes)));
@@ -75,7 +74,7 @@ constexpr auto fitness_function = [](blt::gp::tree_t& current_tree, blt::gp::fit
     BLT_DEBUG("(depth: %ld) (blocks: %ld) (size: t: %ld m: %ld u: %ld r: %ld) filled: %f%%",
               current_tree.get_depth(program), size.blocks, size.total_size_bytes, size.total_no_meta_bytes, size.total_used_bytes,
               size.total_remaining_bytes, static_cast<double>(size.total_used_bytes) / static_cast<double>(size.total_no_meta_bytes));*/
-    result_container[index] = current_tree.get_evaluation_value<float>(nullptr);
+    result_container[index] = current_tree.get_evaluation_value<float>();
     fitness.raw_fitness = result_container[index] / 1000000000.0;
     fitness.standardized_fitness = fitness.raw_fitness;
     fitness.adjusted_fitness = 1.0 - (1.0 / (1.0 + fitness.raw_fitness));
@@ -86,14 +85,11 @@ constexpr auto fitness_function = [](blt::gp::tree_t& current_tree, blt::gp::fit
  */
 int main()
 {
-    type_system.register_type<float>();
-    type_system.register_type<bool>();
-    
-    blt::gp::operator_builder builder{type_system};
+    blt::gp::operator_builder builder{};
     program.set_operations(builder.build(add, sub, mul, pro_div, op_if, eq_f, eq_b, lt, gt, op_and, op_or, op_xor, op_not, lit));
     
     auto sel = blt::gp::select_tournament_t{};
-    program.generate_population(type_system.get_type<float>().id(), fitness_function, sel, sel, sel);
+    program.generate_population(program.get_typesystem().get_type<float>().id(), fitness_function, sel, sel, sel);
     
     while (!program.should_terminate())
     {
diff --git a/tests/order_tests.cpp b/tests/order_tests.cpp
index 9db441b..3ff53ae 100644
--- a/tests/order_tests.cpp
+++ b/tests/order_tests.cpp
@@ -27,7 +27,6 @@
 const blt::u64 SEED = std::random_device()();
 //const blt::u64 SEED = 3495535167;
 blt::gp::random_t b_rand {SEED};
-blt::gp::type_provider type_system;
 
 struct context
 {
@@ -82,18 +81,19 @@ auto basic_lit_b = blt::gp::operation_t([]() {
 
 void basic_test()
 {
-    blt::gp::gp_program program{type_system, SEED};
+    blt::gp::gp_program program{SEED};
     
-    blt::gp::operator_builder<context> builder{type_system};
+    blt::gp::operator_builder<context> builder{};
     
     program.set_operations(builder.build(basic_sub, basic_lit_f, basic_lit_b));
     
     blt::gp::grow_generator_t gen;
-    blt::gp::generator_arguments args{program, type_system.get_type<float>().id(), 1, 1};
-    auto tree = gen.generate(args);
+    blt::gp::generator_arguments args{program, program.get_typesystem().get_type<float>().id(), 1, 1};
+    blt::gp::tree_t tree{program};
+    gen.generate(tree, args);
     
     context ctx{&program};
-    auto result = tree.get_evaluation_value<float>(&ctx);
+    auto result = tree.get_evaluation_value<float>(ctx);
     BLT_TRACE(result);
     BLT_ASSERT(result == -5.0f || result == 5.0f || result == 0.0f);
     tree.print(program, std::cout, true, true);
@@ -103,9 +103,5 @@ int main()
 {
     BLT_INFO("Starting with seed %ld", SEED);
     
-    type_system.register_type<float>();
-    type_system.register_type<bool>();
-    type_system.register_type<large_18290>();
-    
     basic_test();
 }
\ No newline at end of file