diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4563ba2..358f812 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,5 +1,5 @@
 cmake_minimum_required(VERSION 3.25)
-project(lilfbtf5 VERSION 0.1.33)
+project(lilfbtf5 VERSION 0.1.34)
 
 option(ENABLE_ADDRSAN "Enable the address sanitizer" OFF)
 option(ENABLE_UBSAN "Enable the ub sanitizer" OFF)
diff --git a/include/lilfbtf/fwddecl.h b/include/lilfbtf/fwddecl.h
index 3a87e98..3aa7455 100644
--- a/include/lilfbtf/fwddecl.h
+++ b/include/lilfbtf/fwddecl.h
@@ -36,6 +36,7 @@ namespace fb
     
     class type_engine_t;
     class gp_system_t;
+    class gp_population_t;
     
     // no way we are going to have more than 4billion types or functions.
     using type_id = blt::u32;
diff --git a/include/lilfbtf/system.h b/include/lilfbtf/system.h
index a135468..f0f7aea 100644
--- a/include/lilfbtf/system.h
+++ b/include/lilfbtf/system.h
@@ -20,15 +20,29 @@
 #define LILFBTF5_SYSTEM_H
 
 #include <lilfbtf/fwddecl.h>
+#include <lilfbtf/tree.h>
+#include <vector>
 
 namespace fb
 {
     
-    class gp_system_t
+    class gp_population_t
     {
     
     };
     
+    class gp_system_t
+    {
+        private:
+        
+        public:
+            gp_system_t(type_engine_t& types): types(types)
+            {}
+        
+        private:
+            type_engine_t& types;
+    };
+    
 }
 
 #endif //LILFBTF5_SYSTEM_H