diff --git a/code/compiler/12/definition.cpp b/code/compiler/12/definition.cpp
index 5f820b7..535a268 100644
--- a/code/compiler/12/definition.cpp
+++ b/code/compiler/12/definition.cpp
@@ -5,6 +5,7 @@
 #include "llvm_context.hpp"
 #include "type.hpp"
 #include "type_env.hpp"
+#include "graph.hpp"
 #include <llvm/IR/DerivedTypes.h>
 #include <llvm/IR/Function.h>
 #include <llvm/IR/Type.h>
@@ -107,3 +108,58 @@ void definition_data::generate_llvm(llvm_context& ctx) {
         ctx.builder.CreateRetVoid();
     }
 }
+
+void definition_group::find_free(type_mgr& mgr, type_env_ptr& env, std::set<std::string>& into) {
+    this->env = type_scope(env);
+
+    for(auto& def_pair : defs_defn) {
+        def_pair.second->find_free(mgr, env);
+        std::set<std::string> local_dependencies;
+        for(auto& free_var : def_pair.second->free_variables) {
+            if(defs_defn.find(free_var) == defs_defn.end()) {
+                into.insert(free_var);
+            } else {
+                local_dependencies.insert(free_var);
+            }
+        }
+        std::swap(def_pair.second->free_variables, local_dependencies);
+    }
+}
+
+void definition_group::typecheck(type_mgr& mgr) {
+    for(auto& def_data : defs_data) {
+        def_data.second->insert_types(env);
+    }
+    for(auto& def_data : defs_data) {
+        def_data.second->insert_constructors();
+    }
+
+    function_graph dependency_graph;
+
+    for(auto& def_defn : defs_defn) {
+        def_defn.second->find_free(mgr, env);
+        dependency_graph.add_function(def_defn.second->name);
+
+        for(auto& dependency : def_defn.second->free_variables) {
+            if(defs_defn.find(dependency) == defs_defn.end())
+                throw 0;
+            dependency_graph.add_edge(def_defn.second->name, dependency);
+        }
+    }
+
+    std::vector<group_ptr> groups = dependency_graph.compute_order();
+    for(auto it = groups.rbegin(); it != groups.rend(); it++) {
+        auto& group = *it;
+        for(auto& def_defnn_name : group->members) {
+            auto& def_defn = defs_defn.find(def_defnn_name)->second;
+            def_defn->insert_types(mgr);
+        }
+        for(auto& def_defnn_name : group->members) {
+            auto& def_defn = defs_defn.find(def_defnn_name)->second;
+            def_defn->typecheck(mgr);
+        }
+        for(auto& def_defnn_name : group->members) {
+            env->generalize(def_defnn_name, mgr);
+        }
+    }
+}
diff --git a/code/compiler/12/definition.hpp b/code/compiler/12/definition.hpp
index d70d539..a063dec 100644
--- a/code/compiler/12/definition.hpp
+++ b/code/compiler/12/definition.hpp
@@ -75,4 +75,9 @@ using definition_data_ptr = std::unique_ptr<definition_data>;
 struct definition_group {
     std::map<std::string, definition_data_ptr> defs_data;
     std::map<std::string, definition_defn_ptr> defs_defn;
+
+    type_env_ptr env;
+
+    void find_free(type_mgr& mgr, type_env_ptr& env, std::set<std::string>& into);
+    void typecheck(type_mgr& mgr);
 };
diff --git a/code/compiler/12/graph.hpp b/code/compiler/12/graph.hpp
index 2db8d7c..2807442 100644
--- a/code/compiler/12/graph.hpp
+++ b/code/compiler/12/graph.hpp
@@ -7,7 +7,6 @@
 #include <map>
 #include <memory>
 #include <vector>
-#include <iostream>
 
 using function = std::string;
 
diff --git a/code/compiler/12/main.cpp b/code/compiler/12/main.cpp
index 6495d92..2ec963c 100644
--- a/code/compiler/12/main.cpp
+++ b/code/compiler/12/main.cpp
@@ -24,8 +24,7 @@ void yy::parser::error(const std::string& msg) {
 extern definition_group global_defs;
 
 void typecheck_program(
-        const std::map<std::string, definition_data_ptr>& defs_data,
-        const std::map<std::string, definition_defn_ptr>& defs_defn,
+        definition_group& defs,
         type_mgr& mgr, type_env_ptr& env) {
     type_ptr int_type = type_ptr(new type_base("Int")); 
     env->bind_type("Int", int_type);
@@ -39,43 +38,11 @@ void typecheck_program(
     env->bind("*", binop_type);
     env->bind("/", binop_type);
 
-    for(auto& def_data : defs_data) {
-        def_data.second->insert_types(env);
-    }
-    for(auto& def_data : defs_data) {
-        def_data.second->insert_constructors();
-    }
+    std::set<std::string> free;
+    defs.find_free(mgr, env, free);
+    defs.typecheck(mgr);
 
-    function_graph dependency_graph;
-
-    for(auto& def_defn : defs_defn) {
-        def_defn.second->find_free(mgr, env);
-        dependency_graph.add_function(def_defn.second->name);
-
-        for(auto& dependency : def_defn.second->free_variables) {
-            if(defs_defn.find(dependency) == defs_defn.end())
-                throw 0;
-            dependency_graph.add_edge(def_defn.second->name, dependency);
-        }
-    }
-
-    std::vector<group_ptr> groups = dependency_graph.compute_order();
-    for(auto it = groups.rbegin(); it != groups.rend(); it++) {
-        auto& group = *it;
-        for(auto& def_defnn_name : group->members) {
-            auto& def_defn = defs_defn.find(def_defnn_name)->second;
-            def_defn->insert_types(mgr);
-        }
-        for(auto& def_defnn_name : group->members) {
-            auto& def_defn = defs_defn.find(def_defnn_name)->second;
-            def_defn->typecheck(mgr);
-        }
-        for(auto& def_defnn_name : group->members) {
-            env->generalize(def_defnn_name, mgr);
-        }
-    }
-
-    for(auto& pair : env->names) {
+    for(auto& pair : defs.env->names) {
         std::cout << pair.first << ": ";
         pair.second->print(mgr, std::cout);
         std::cout << std::endl;
@@ -187,7 +154,7 @@ int main() {
         def_defn.second->body->print(1, std::cout);
     }
     try {
-        typecheck_program(global_defs.defs_data, global_defs.defs_defn, mgr, env);
+        typecheck_program(global_defs, mgr, env);
         compile_program(global_defs.defs_defn);
         gen_llvm(global_defs.defs_data, global_defs.defs_defn);
     } catch(unification_error& err) {