diff --git a/code/compiler/10/ast.cpp b/code/compiler/10/ast.cpp
index 0abbb10..9ea0822 100644
--- a/code/compiler/10/ast.cpp
+++ b/code/compiler/10/ast.cpp
@@ -2,6 +2,7 @@
 #include <ostream>
 #include "binop.hpp"
 #include "error.hpp"
+#include "type_env.hpp"
 
 static void print_indent(int n, std::ostream& to) {
     while(n--) to << "  ";
@@ -12,7 +13,11 @@ void ast_int::print(int indent, std::ostream& to) const {
     to << "INT: " << value << std::endl;
 }
 
-type_ptr ast_int::typecheck(type_mgr& mgr, const type_env& env) {
+void ast_int::find_free(type_mgr& mgr, type_env_ptr& env, std::set<std::string>& into) {
+    this->env = env;
+}
+
+type_ptr ast_int::typecheck(type_mgr& mgr) {
     return type_ptr(new type_base("Int"));
 }
 
@@ -25,8 +30,13 @@ void ast_lid::print(int indent, std::ostream& to) const {
     to << "LID: " << id << std::endl;
 }
 
-type_ptr ast_lid::typecheck(type_mgr& mgr, const type_env& env) {
-    return env.lookup(id);
+void ast_lid::find_free(type_mgr& mgr, type_env_ptr& env, std::set<std::string>& into) {
+    this->env = env;
+    if(env->lookup(id) == nullptr) into.insert(id);
+}
+
+type_ptr ast_lid::typecheck(type_mgr& mgr) {
+    return env->lookup(id);
 }
 
 void ast_lid::compile(const env_ptr& env, std::vector<instruction_ptr>& into) const {
@@ -41,8 +51,12 @@ void ast_uid::print(int indent, std::ostream& to) const {
     to << "UID: " << id << std::endl;
 }
 
-type_ptr ast_uid::typecheck(type_mgr& mgr, const type_env& env) {
-    return env.lookup(id);
+void ast_uid::find_free(type_mgr& mgr, type_env_ptr& env, std::set<std::string>& into) {
+    this->env = env;
+}
+
+type_ptr ast_uid::typecheck(type_mgr& mgr) {
+    return env->lookup(id);
 }
 
 void ast_uid::compile(const env_ptr& env, std::vector<instruction_ptr>& into) const {
@@ -56,10 +70,16 @@ void ast_binop::print(int indent, std::ostream& to) const {
     right->print(indent + 1, to);
 }
 
-type_ptr ast_binop::typecheck(type_mgr& mgr, const type_env& env) {
-    type_ptr ltype = left->typecheck(mgr, env);
-    type_ptr rtype = right->typecheck(mgr, env);
-    type_ptr ftype = env.lookup(op_name(op));
+void ast_binop::find_free(type_mgr& mgr, type_env_ptr& env, std::set<std::string>& into) {
+    this->env = env;
+    left->find_free(mgr, env, into);
+    right->find_free(mgr, env, into);
+}
+
+type_ptr ast_binop::typecheck(type_mgr& mgr) {
+    type_ptr ltype = left->typecheck(mgr);
+    type_ptr rtype = right->typecheck(mgr);
+    type_ptr ftype = env->lookup(op_name(op));
     if(!ftype) throw type_error(std::string("unknown binary operator ") + op_name(op));
 
     type_ptr return_type = mgr.new_type();
@@ -86,9 +106,15 @@ void ast_app::print(int indent, std::ostream& to) const {
     right->print(indent + 1, to);
 }
 
-type_ptr ast_app::typecheck(type_mgr& mgr, const type_env& env) {
-    type_ptr ltype = left->typecheck(mgr, env);
-    type_ptr rtype = right->typecheck(mgr, env);
+void ast_app::find_free(type_mgr& mgr, type_env_ptr& env, std::set<std::string>& into) {
+    this->env = env;
+    left->find_free(mgr, env, into);
+    right->find_free(mgr, env, into);
+}
+
+type_ptr ast_app::typecheck(type_mgr& mgr) {
+    type_ptr ltype = left->typecheck(mgr);
+    type_ptr rtype = right->typecheck(mgr);
 
     type_ptr return_type = mgr.new_type();
     type_ptr arrow = type_ptr(new type_arr(rtype, return_type));
@@ -113,15 +139,24 @@ void ast_case::print(int indent, std::ostream& to) const {
     }
 }
 
-type_ptr ast_case::typecheck(type_mgr& mgr, const type_env& env) {
+void ast_case::find_free(type_mgr& mgr, type_env_ptr& env, std::set<std::string>& into) {
+    this->env = env;
+    of->find_free(mgr, env, into);
+    for(auto& branch : branches) {
+        type_env_ptr new_env = type_scope(env);
+        branch->pat->insert_bindings(mgr, new_env);
+        branch->expr->find_free(mgr, new_env, into);
+    }
+}
+
+type_ptr ast_case::typecheck(type_mgr& mgr) {
     type_var* var;
-    type_ptr case_type = mgr.resolve(of->typecheck(mgr, env), var);
+    type_ptr case_type = mgr.resolve(of->typecheck(mgr), var);
     type_ptr branch_type = mgr.new_type();
 
     for(auto& branch : branches) {
-        type_env new_env = env.scope();
-        branch->pat->match(case_type, mgr, new_env);
-        type_ptr curr_branch_type = branch->expr->typecheck(mgr, new_env);
+        branch->pat->typecheck(case_type, mgr, branch->expr->env);
+        type_ptr curr_branch_type = branch->expr->typecheck(mgr);
         mgr.unify(branch_type, curr_branch_type);
     }
 
@@ -192,8 +227,12 @@ void pattern_var::print(std::ostream& to) const {
     to << var;
 }
 
-void pattern_var::match(type_ptr t, type_mgr& mgr, type_env& env) const {
-    env.bind(var, t);
+void pattern_var::insert_bindings(type_mgr& mgr, type_env_ptr& env) const {
+    env->bind(var, mgr.new_type());
+}
+
+void pattern_var::typecheck(type_ptr t, type_mgr& mgr, type_env_ptr& env) const {
+    mgr.unify(env->lookup(var), t);
 }
 
 void pattern_constr::print(std::ostream& to) const {
@@ -203,17 +242,23 @@ void pattern_constr::print(std::ostream& to) const {
     }
 }
 
-void pattern_constr::match(type_ptr t, type_mgr& mgr, type_env& env) const {
-    type_ptr constructor_type = env.lookup(constr);
+void pattern_constr::insert_bindings(type_mgr& mgr, type_env_ptr& env) const {
+    for(auto& param : params) {
+        env->bind(param, mgr.new_type());
+    }
+}
+
+void pattern_constr::typecheck(type_ptr t, type_mgr& mgr, type_env_ptr& env) const {
+    type_ptr constructor_type = env->lookup(constr);
     if(!constructor_type) {
         throw type_error(std::string("pattern using unknown constructor ") + constr);
     }
 
-    for(int i = 0; i < params.size(); i++) {
+    for(auto& param : params) {
         type_arr* arr = dynamic_cast<type_arr*>(constructor_type.get());
         if(!arr) throw type_error("too many parameters in constructor pattern");
 
-        env.bind(params[i], arr->left);
+        mgr.unify(env->lookup(param), arr->left);
         constructor_type = arr->right;
     }
 
diff --git a/code/compiler/10/ast.hpp b/code/compiler/10/ast.hpp
index 98b6b24..6c66636 100644
--- a/code/compiler/10/ast.hpp
+++ b/code/compiler/10/ast.hpp
@@ -1,6 +1,7 @@
 #pragma once
 #include <memory>
 #include <vector>
+#include <set>
 #include "type.hpp"
 #include "type_env.hpp"
 #include "binop.hpp"
@@ -8,10 +9,14 @@
 #include "env.hpp"
 
 struct ast {
+    type_env_ptr env;
+
     virtual ~ast() = default;
 
     virtual void print(int indent, std::ostream& to) const = 0;
-    virtual type_ptr typecheck(type_mgr& mgr, const type_env& env) = 0;
+    virtual void find_free(type_mgr& mgr,
+        type_env_ptr& env, std::set<std::string>& into) = 0;
+    virtual type_ptr typecheck(type_mgr& mgr) = 0;
     virtual void compile(const env_ptr& env,
         std::vector<instruction_ptr>& into) const = 0;
 };
@@ -22,7 +27,8 @@ struct pattern {
     virtual ~pattern() = default;
 
     virtual void print(std::ostream& to) const = 0;
-    virtual void match(type_ptr t, type_mgr& mgr, type_env& env) const = 0;
+    virtual void insert_bindings(type_mgr& mgr, type_env_ptr& env) const = 0;
+    virtual void typecheck(type_ptr t, type_mgr& mgr, type_env_ptr& env) const = 0;
 };
 
 using pattern_ptr = std::unique_ptr<pattern>;
@@ -44,7 +50,8 @@ struct ast_int : public ast {
         : value(v) {}
 
     void print(int indent, std::ostream& to) const;
-    type_ptr typecheck(type_mgr& mgr, const type_env& env);
+    void find_free(type_mgr& mgr, type_env_ptr& env, std::set<std::string>& into);
+    type_ptr typecheck(type_mgr& mgr);
     void compile(const env_ptr& env, std::vector<instruction_ptr>& into) const;
 };
 
@@ -55,7 +62,8 @@ struct ast_lid : public ast {
         : id(std::move(i)) {}
 
     void print(int indent, std::ostream& to) const;
-    type_ptr typecheck(type_mgr& mgr, const type_env& env);
+    void find_free(type_mgr& mgr, type_env_ptr& env, std::set<std::string>& into);
+    type_ptr typecheck(type_mgr& mgr);
     void compile(const env_ptr& env, std::vector<instruction_ptr>& into) const;
 };
 
@@ -66,7 +74,8 @@ struct ast_uid : public ast {
         : id(std::move(i)) {}
 
     void print(int indent, std::ostream& to) const;
-    type_ptr typecheck(type_mgr& mgr, const type_env& env);
+    void find_free(type_mgr& mgr, type_env_ptr& env, std::set<std::string>& into);
+    type_ptr typecheck(type_mgr& mgr);
     void compile(const env_ptr& env, std::vector<instruction_ptr>& into) const;
 };
 
@@ -79,7 +88,8 @@ struct ast_binop : public ast {
         : op(o), left(std::move(l)), right(std::move(r)) {}
 
     void print(int indent, std::ostream& to) const;
-    type_ptr typecheck(type_mgr& mgr, const type_env& env);
+    void find_free(type_mgr& mgr, type_env_ptr& env, std::set<std::string>& into);
+    type_ptr typecheck(type_mgr& mgr);
     void compile(const env_ptr& env, std::vector<instruction_ptr>& into) const;
 };
 
@@ -91,7 +101,8 @@ struct ast_app : public ast {
         : left(std::move(l)), right(std::move(r)) {}
 
     void print(int indent, std::ostream& to) const;
-    type_ptr typecheck(type_mgr& mgr, const type_env& env);
+    void find_free(type_mgr& mgr, type_env_ptr& env, std::set<std::string>& into);
+    type_ptr typecheck(type_mgr& mgr);
     void compile(const env_ptr& env, std::vector<instruction_ptr>& into) const;
 };
 
@@ -104,7 +115,8 @@ struct ast_case : public ast {
         : of(std::move(o)), branches(std::move(b)) {}
 
     void print(int indent, std::ostream& to) const;
-    type_ptr typecheck(type_mgr& mgr, const type_env& env);
+    void find_free(type_mgr& mgr, type_env_ptr& env, std::set<std::string>& into);
+    type_ptr typecheck(type_mgr& mgr);
     void compile(const env_ptr& env, std::vector<instruction_ptr>& into) const;
 };
 
@@ -115,7 +127,8 @@ struct pattern_var : public pattern {
         : var(std::move(v)) {}
 
     void print(std::ostream &to) const;
-    void match(type_ptr t, type_mgr& mgr, type_env& env) const;
+    void insert_bindings(type_mgr& mgr, type_env_ptr& env) const;
+    void typecheck(type_ptr t, type_mgr& mgr, type_env_ptr& env) const;
 };
 
 struct pattern_constr : public pattern {
@@ -126,5 +139,6 @@ struct pattern_constr : public pattern {
         : constr(std::move(c)), params(std::move(p)) {}
 
     void print(std::ostream &to) const;
-    void match(type_ptr t, type_mgr&, type_env& env) const;
+    virtual void insert_bindings(type_mgr& mgr, type_env_ptr& env) const;
+    virtual void typecheck(type_ptr t, type_mgr& mgr, type_env_ptr& env) const;
 };
diff --git a/code/compiler/10/definition.cpp b/code/compiler/10/definition.cpp
index 4a14571..c4bf4f7 100644
--- a/code/compiler/10/definition.cpp
+++ b/code/compiler/10/definition.cpp
@@ -3,35 +3,33 @@
 #include "ast.hpp"
 #include "instruction.hpp"
 #include "llvm_context.hpp"
+#include "type_env.hpp"
 #include <llvm/IR/DerivedTypes.h>
 #include <llvm/IR/Function.h>
 #include <llvm/IR/Type.h>
 
-void definition_defn::typecheck_first(type_mgr& mgr, type_env& env) {
+void definition_defn::find_free(type_mgr& mgr, type_env_ptr& env) {
+    this->env = env;
+
+    var_env = type_scope(env);
     return_type = mgr.new_type();
-    type_ptr full_type = return_type;
+    full_type = return_type;
 
     for(auto it = params.rbegin(); it != params.rend(); it++) {
         type_ptr param_type = mgr.new_type();
         full_type = type_ptr(new type_arr(param_type, full_type));
-        param_types.push_back(param_type);
+        var_env->bind(*it, param_type);
     }
 
-    env.bind(name, full_type);
+    body->find_free(mgr, var_env, free_variables);
 }
 
-void definition_defn::typecheck_second(type_mgr& mgr, const type_env& env) const {
-    type_env new_env = env.scope();
-    auto param_it = params.begin();
-    auto type_it = param_types.rbegin();
+void definition_defn::insert_types(type_mgr& mgr) {
+    env->bind(name, full_type);
+}
 
-    while(param_it != params.end() && type_it != param_types.rend()) {
-        new_env.bind(*param_it, *type_it);
-        param_it++;
-        type_it++;
-    }
-
-    type_ptr body_type = body->typecheck(mgr, new_env);
+void definition_defn::typecheck(type_mgr& mgr) {
+    type_ptr body_type = body->typecheck(mgr);
     mgr.unify(return_type, body_type);
 }
 
@@ -44,11 +42,12 @@ void definition_defn::compile() {
     instructions.push_back(instruction_ptr(new instruction_update(params.size())));
     instructions.push_back(instruction_ptr(new instruction_pop(params.size())));
 }
-void definition_defn::gen_llvm_first(llvm_context& ctx) {
+
+void definition_defn::declare_llvm(llvm_context& ctx) {
     generated_function = ctx.create_custom_function(name, params.size());
 }
 
-void definition_defn::gen_llvm_second(llvm_context& ctx) {
+void definition_defn::generate_llvm(llvm_context& ctx) {
     ctx.builder.SetInsertPoint(&generated_function->getEntryBlock());
     for(auto& instruction : instructions) {
         instruction->gen_llvm(ctx, generated_function);
@@ -56,7 +55,11 @@ void definition_defn::gen_llvm_second(llvm_context& ctx) {
     ctx.builder.CreateRetVoid();
 }
 
-void definition_data::typecheck_first(type_mgr& mgr, type_env& env) {
+void definition_data::insert_types(type_mgr& mgr, type_env_ptr& env) {
+    this->env = env;
+}
+
+void definition_data::insert_constructors() const {
     type_data* this_type = new type_data(name);
     type_ptr return_type = type_ptr(this_type);
     int next_tag = 0;
@@ -71,19 +74,11 @@ void definition_data::typecheck_first(type_mgr& mgr, type_env& env) {
             full_type = type_ptr(new type_arr(type, full_type));
         }
 
-        env.bind(constructor->name, full_type);
+        env->bind(constructor->name, full_type);
     }
 }
 
-void definition_data::typecheck_second(type_mgr& mgr, const type_env& env) const {
-    // Nothing
-}
-
-void definition_data::compile() {
-
-}
-
-void definition_data::gen_llvm_first(llvm_context& ctx) {
+void definition_data::generate_llvm(llvm_context& ctx) {
     for(auto& constructor : constructors) {
         auto new_function =
             ctx.create_custom_function(constructor->name, constructor->types.size());
@@ -99,7 +94,3 @@ void definition_data::gen_llvm_first(llvm_context& ctx) {
         ctx.builder.CreateRetVoid();
     }
 }
-
-void definition_data::gen_llvm_second(llvm_context& ctx) {
-    // Nothing
-}
diff --git a/code/compiler/10/definition.hpp b/code/compiler/10/definition.hpp
index 74a2b69..b72bed6 100644
--- a/code/compiler/10/definition.hpp
+++ b/code/compiler/10/definition.hpp
@@ -1,6 +1,7 @@
 #pragma once
 #include <memory>
 #include <vector>
+#include <set>
 #include "instruction.hpp"
 #include "llvm_context.hpp"
 #include "type_env.hpp"
@@ -8,18 +9,6 @@
 struct ast;
 using ast_ptr = std::unique_ptr<ast>;
 
-struct definition {
-    virtual ~definition() = default;
-    
-    virtual void typecheck_first(type_mgr& mgr, type_env& env) = 0;
-    virtual void typecheck_second(type_mgr& mgr, const type_env& env) const = 0;
-    virtual void compile() = 0;
-    virtual void gen_llvm_first(llvm_context& ctx) = 0;
-    virtual void gen_llvm_second(llvm_context& ctx) = 0;
-};
-
-using definition_ptr = std::unique_ptr<definition>;
-
 struct constructor {
     std::string name;
     std::vector<std::string> types;
@@ -31,13 +20,16 @@ struct constructor {
 
 using constructor_ptr = std::unique_ptr<constructor>;
 
-struct definition_defn : public definition {
+struct definition_defn {
     std::string name;
     std::vector<std::string> params;
     ast_ptr body;
 
+    type_env_ptr env;
+    type_env_ptr var_env;
+    std::set<std::string> free_variables;
+    type_ptr full_type;
     type_ptr return_type;
-    std::vector<type_ptr> param_types;
 
     std::vector<instruction_ptr> instructions;
 
@@ -48,23 +40,28 @@ struct definition_defn : public definition {
 
     }
 
-    void typecheck_first(type_mgr& mgr, type_env& env);
-    void typecheck_second(type_mgr& mgr, const type_env& env) const;
+    void find_free(type_mgr& mgr, type_env_ptr& env);
+    void insert_types(type_mgr& mgr);
+    void typecheck(type_mgr& mgr);
     void compile();
-    void gen_llvm_first(llvm_context& ctx);
-    void gen_llvm_second(llvm_context& ctx);
+    void declare_llvm(llvm_context& ctx);
+    void generate_llvm(llvm_context& ctx);
 };
 
-struct definition_data : public definition {
+using definition_defn_ptr = std::unique_ptr<definition_defn>;
+
+struct definition_data {
     std::string name;
     std::vector<constructor_ptr> constructors;
 
+    type_env_ptr env;
+
     definition_data(std::string n, std::vector<constructor_ptr> cs)
         : name(std::move(n)), constructors(std::move(cs)) {}
 
-    void typecheck_first(type_mgr& mgr, type_env& env);
-    void typecheck_second(type_mgr& mgr, const type_env& env) const;
-    void compile();
-    void gen_llvm_first(llvm_context& ctx);
-    void gen_llvm_second(llvm_context& ctx);
+    void insert_types(type_mgr& mgr, type_env_ptr& env);
+    void insert_constructors() const;
+    void generate_llvm(llvm_context& ctx);
 };
+
+using definition_data_ptr = std::unique_ptr<definition_data>;
diff --git a/code/compiler/10/main.cpp b/code/compiler/10/main.cpp
index 27529b7..dd59316 100644
--- a/code/compiler/10/main.cpp
+++ b/code/compiler/10/main.cpp
@@ -20,43 +20,52 @@ void yy::parser::error(const std::string& msg) {
     std::cout << "An error occured: " << msg << std::endl;
 }
 
-extern std::vector<definition_ptr> program;
+extern std::vector<definition_data_ptr> defs_data;
+extern std::vector<definition_defn_ptr> defs_defn;
 
 void typecheck_program(
-        const std::vector<definition_ptr>& prog,
-        type_mgr& mgr, type_env& env) {
+        const std::vector<definition_data_ptr>& defs_data,
+        const std::vector<definition_defn_ptr>& defs_defn,
+        type_mgr& mgr, type_env_ptr& env) {
     type_ptr int_type = type_ptr(new type_base("Int")); 
     type_ptr binop_type = type_ptr(new type_arr(
                 int_type,
                 type_ptr(new type_arr(int_type, int_type))));
 
-    env.bind("+", binop_type);
-    env.bind("-", binop_type);
-    env.bind("*", binop_type);
-    env.bind("/", binop_type);
+    env->bind("+", binop_type);
+    env->bind("-", binop_type);
+    env->bind("*", binop_type);
+    env->bind("/", binop_type);
 
-    for(auto& def : prog) {
-        def->typecheck_first(mgr, env);
+    for(auto& def_data : defs_data) {
+        def_data->insert_types(mgr, env);
+    }
+    for(auto& def_data : defs_data) {
+        def_data->insert_constructors();
     }
 
-    for(auto& def : prog) {
-        def->typecheck_second(mgr, env);
+    for(auto& def_defn : defs_defn) {
+        def_defn->find_free(mgr, env);
+    }
+    for(auto& def_defn : defs_defn) {
+        def_defn->insert_types(mgr);
+    }
+    for(auto& def_defn : defs_defn) {
+        def_defn->typecheck(mgr);
     }
 
-    for(auto& pair : env.names) {
+    for(auto& pair : env->names) {
         std::cout << pair.first << ": ";
         pair.second->print(mgr, std::cout);
         std::cout << std::endl;
     }
 }
 
-void compile_program(const std::vector<definition_ptr>& prog) {
-    for(auto& def : prog) {
-        def->compile();
+void compile_program(const std::vector<definition_defn_ptr>& defs_defn) {
+    for(auto& def_defn : defs_defn) {
+        def_defn->compile();
 
-        definition_defn* defn = dynamic_cast<definition_defn*>(def.get());
-        if(!defn) continue;
-        for(auto& instruction : defn->instructions) {
+        for(auto& instruction : def_defn->instructions) {
             instruction->print(0, std::cout);
         }
         std::cout << std::endl;
@@ -120,20 +129,25 @@ void output_llvm(llvm_context& ctx, const std::string& filename) {
     }
 }
 
-void gen_llvm(const std::vector<definition_ptr>& prog) {
+void gen_llvm(
+        const std::vector<definition_data_ptr>& defs_data,
+        const std::vector<definition_defn_ptr>& defs_defn) {
     llvm_context ctx;
     gen_llvm_internal_op(ctx, PLUS);
     gen_llvm_internal_op(ctx, MINUS);
     gen_llvm_internal_op(ctx, TIMES);
     gen_llvm_internal_op(ctx, DIVIDE);
 
-    for(auto& definition : prog) {
-        definition->gen_llvm_first(ctx);
+    for(auto& def_data : defs_data) {
+        def_data->generate_llvm(ctx);
+    }
+    for(auto& def_defn : defs_defn) {
+        def_defn->declare_llvm(ctx);
+    }
+    for(auto& def_defn : defs_defn) {
+        def_defn->generate_llvm(ctx);
     }
 
-    for(auto& definition : prog) {
-        definition->gen_llvm_second(ctx);
-    }
     ctx.module.print(llvm::outs(), nullptr);
     output_llvm(ctx, "program.o");
 }
@@ -141,23 +155,20 @@ void gen_llvm(const std::vector<definition_ptr>& prog) {
 int main() {
     yy::parser parser;
     type_mgr mgr;
-    type_env env;
+    type_env_ptr env(new type_env);
 
     parser.parse();
-    for(auto& definition : program) {
-        definition_defn* def = dynamic_cast<definition_defn*>(definition.get());
-        if(!def) continue;
-
-        std::cout << def->name;
-        for(auto& param : def->params) std::cout << " " << param;
+    for(auto& def_defn : defs_defn) {
+        std::cout << def_defn->name;
+        for(auto& param : def_defn->params) std::cout << " " << param;
         std::cout << ":" << std::endl;
 
-        def->body->print(1, std::cout);
+        def_defn->body->print(1, std::cout);
     }
     try {
-        typecheck_program(program, mgr, env);
-        compile_program(program);
-        gen_llvm(program);
+        typecheck_program(defs_data, defs_defn, mgr, env);
+        compile_program(defs_defn);
+        gen_llvm(defs_data, defs_defn);
     } catch(unification_error& err) {
         std::cout << "failed to unify types: " << std::endl;
         std::cout << "  (1) \033[34m";
diff --git a/code/compiler/10/parser.y b/code/compiler/10/parser.y
index 088648d..9614126 100644
--- a/code/compiler/10/parser.y
+++ b/code/compiler/10/parser.y
@@ -5,7 +5,9 @@
 #include "definition.hpp"
 #include "parser.hpp"
 
-std::vector<definition_ptr> program;
+std::vector<definition_data_ptr> defs_data;
+std::vector<definition_defn_ptr> defs_defn;
+
 extern yy::parser::symbol_type yylex();
 
 %}
@@ -34,11 +36,11 @@ extern yy::parser::symbol_type yylex();
 %define api.token.constructor
 
 %type <std::vector<std::string>> lowercaseParams uppercaseParams
-%type <std::vector<definition_ptr>> program definitions
 %type <std::vector<branch_ptr>> branches
 %type <std::vector<constructor_ptr>> constructors
 %type <ast_ptr> aAdd aMul case app appBase
-%type <definition_ptr> definition defn data 
+%type <definition_data_ptr> data 
+%type <definition_defn_ptr> defn
 %type <branch_ptr> branch
 %type <pattern_ptr> pattern
 %type <constructor_ptr> constructor
@@ -48,22 +50,22 @@ extern yy::parser::symbol_type yylex();
 %%
 
 program
-    : definitions { program = std::move($1); }
+    : definitions { }
     ;
 
 definitions
-    : definitions definition { $$ = std::move($1); $$.push_back(std::move($2)); }
-    | definition { $$ = std::vector<definition_ptr>(); $$.push_back(std::move($1)); }
+    : definitions definition { }
+    | definition { }
     ;
 
 definition
-    : defn { $$ = std::move($1); }
-    | data { $$ = std::move($1); }
+    : defn { defs_defn.push_back(std::move($1)); }
+    | data { defs_data.push_back(std::move($1)); }
     ;
 
 defn
     : DEFN LID lowercaseParams EQUAL OCURLY aAdd CCURLY
-        { $$ = definition_ptr(
+        { $$ = definition_defn_ptr(
             new definition_defn(std::move($2), std::move($3), std::move($6))); }
     ;
 
@@ -125,7 +127,7 @@ pattern
 
 data
     : DATA UID EQUAL OCURLY constructors CCURLY
-        { $$ = definition_ptr(new definition_data(std::move($2), std::move($5))); }
+        { $$ = definition_data_ptr(new definition_data(std::move($2), std::move($5))); }
     ;
 
 constructors