diff --git a/implementations/c/src/cons.c b/implementations/c/src/cons.c
index f7fa251..db98031 100644
--- a/implementations/c/src/cons.c
+++ b/implementations/c/src/cons.c
@@ -17,18 +17,22 @@ Pointer reduce_fn(Pointer args, Pointer env) {
   return previous;
 }
 
-Pointer cons_fn(Pointer args) {
+Pointer cons_fn(Pointer args, Pointer env) {
+  (void) env;
   return cons(CAR(args), CAR(CDR(args)));
 }
 
-Pointer car_fn(Pointer args) {
+Pointer car_fn(Pointer args, Pointer env) {
+  (void) env;
   return CAR(CAR(args));
 }
 
-Pointer cdr_fn(Pointer args) {
+Pointer cdr_fn(Pointer args, Pointer env) {
+  (void) env;
   return CDR(CAR(args));
 }
 
-Pointer list_fn(Pointer args) {
+Pointer list_fn(Pointer args, Pointer env) {
+  (void) env;
   return args;
 }
diff --git a/implementations/c/src/evaluator.c b/implementations/c/src/evaluator.c
index f146b35..e3c9e05 100644
--- a/implementations/c/src/evaluator.c
+++ b/implementations/c/src/evaluator.c
@@ -43,7 +43,7 @@ Pointer eval(Pointer data, Pointer env) {
     }
     
     if (type == NATIVE_FUNC) {
-      return NATIVE_FUNC(op)(params);
+      return NATIVE_FUNC(op)(params, env);
     }
     
     if (type == FUNC) {
diff --git a/implementations/c/src/lisp.c b/implementations/c/src/lisp.c
index 69ee377..2d12ccc 100644
--- a/implementations/c/src/lisp.c
+++ b/implementations/c/src/lisp.c
@@ -31,15 +31,17 @@ Pointer func(Pointer code, Pointer env) {
   return fn;
 }
 
-/** OPERATIONS **/
+/** FUNCTIONS **/
 
-Pointer add_fn(Pointer args) {
+Pointer add_fn(Pointer args, Pointer env) {
+  (void) env;
   Pointer result = number(0);
   REDUCE(args, result; NUMBER(result) += NUMBER(CAR(args)), result);
   return result;
 }
 
-Pointer sub_fn(Pointer args) {
+Pointer sub_fn(Pointer args, Pointer env) {
+  (void) env;
   Pointer first = CAR(args);
   Pointer rest = CDR(args);
   if (first == NIL) return UNDEFINED; // Empty args
@@ -49,13 +51,15 @@ Pointer sub_fn(Pointer args) {
   return result;
 }
 
-Pointer mul_fn(Pointer args) {
+Pointer mul_fn(Pointer args, Pointer env) {
+  (void) env;
   Pointer result = number(1);
   REDUCE(args, result; NUMBER(result) *= NUMBER(CAR(args)), result);
   return result;
 }
 
-Pointer div_fn(Pointer args) {
+Pointer div_fn(Pointer args, Pointer env) {
+  (void) env;
   Pointer first = CAR(args);
   Pointer rest = CDR(args);
   if (first == NIL) return UNDEFINED; // Empty args
@@ -65,20 +69,23 @@ Pointer div_fn(Pointer args) {
   return result;
 }
 
-Pointer pow_fn(Pointer args) {
+Pointer pow_fn(Pointer args, Pointer env) {
+  (void) env;
   Pointer a = CAR(args);
   Pointer b = CAR(CDR(args));
   if (a == NIL || b == NIL) return UNDEFINED; // Arguments missing.
   return number(pow(NUMBER(a), NUMBER(b)));
 }
 
-Pointer sqrt_fn(Pointer args) {
+Pointer sqrt_fn(Pointer args, Pointer env) {
+  (void) env;
   Pointer a = CAR(args);
   if (a == NIL) return UNDEFINED; // Arguments missing.
   return number(sqrt(NUMBER(a)));
 }
 
-Pointer logand_fn(Pointer args) {
+Pointer logand_fn(Pointer args, Pointer env) {
+  (void) env;
   Pointer result = number(-1l);
   REDUCE(args,
 	 result; NUMBER(result) = (long) NUMBER(result) & (long) NUMBER(CAR(args)),
@@ -86,7 +93,8 @@ Pointer logand_fn(Pointer args) {
   return result;
 }
 
-Pointer logor_fn(Pointer args) {
+Pointer logor_fn(Pointer args, Pointer env) {
+  (void) env;
   Pointer result = number(0);
   REDUCE(args,
 	 result; NUMBER(result) = (long) NUMBER(result) | (long) NUMBER(CAR(args)),
@@ -94,7 +102,8 @@ Pointer logor_fn(Pointer args) {
   return result;
 }
 
-Pointer logxor_fn(Pointer args) {
+Pointer logxor_fn(Pointer args, Pointer env) {
+  (void) env;
   Pointer result = number(0);
   REDUCE(args,
 	 result; NUMBER(result) = (long) NUMBER(result) ^ (long) NUMBER(CAR(args)),
@@ -102,7 +111,8 @@ Pointer logxor_fn(Pointer args) {
   return result;
 }
 
-Pointer lognot_fn(Pointer args) {
+Pointer lognot_fn(Pointer args, Pointer env) {
+  (void) env;
   Pointer a = CAR(args);
   if (a == NIL) return UNDEFINED; // Arguments missing.
   return number(~(long) NUMBER(a));
@@ -164,7 +174,8 @@ Pointer or_fn(Pointer args, Pointer env) {
   return NIL;
 }
 
-Pointer not_fn(Pointer args) {
+Pointer not_fn(Pointer args, Pointer env) {
+  (void) env;
   return CAR(args) == NIL ? T : NIL;
 }
 
@@ -187,6 +198,9 @@ Pointer fn_fn(Pointer args, Pointer env) {
   return func(args, env);
 }
 
+#define SET_FUNC(s, fn) environment_set(NIL, symbol1(s), native_func(fn))
+#define SET_FORM(s, fn) environment_set(NIL, symbol1(s), special_form(fn))
+
 void init(void) {
   memory_init(16);
   symbol_init();
@@ -194,8 +208,9 @@ void init(void) {
   environment_init();
   environment_set(NIL, STANDARD_INPUT, stream(stdin));
   environment_set(NIL, STANDARD_OUTPUT, stream(stdout));
-  Pointer add = symbol1("+");
-  environment_set(NIL, add, native_func(add_fn));
+  SET_FUNC("+", add_fn);
+  SET_FUNC("-", sub_fn);
+  SET_FUNC("*", mul_fn);
 }
 
 void repl(void) {
diff --git a/implementations/c/src/lisp.h b/implementations/c/src/lisp.h
index 8412fad..9a488f9 100644
--- a/implementations/c/src/lisp.h
+++ b/implementations/c/src/lisp.h
@@ -74,11 +74,9 @@ typedef struct {
 } Table;
 
 /* CHANGER POUR TABLEAU DE FONCTIONS */
-typedef Pointer (*NativeFunc)(Pointer params);
+typedef Pointer (*NativeFunc)(Pointer params, Pointer env);
 typedef Pointer (*SpecialForm)(Pointer params, Pointer env);
 
-/* FIN A RETRAVAILLER! */
-
 typedef FILE* Stream;
 
 typedef union {
@@ -172,36 +170,36 @@ Pointer special_form(SpecialForm func);
 Pointer character(Char c);
 Pointer stream(FILE* s);
 
-/* OPERATIONS */
+/* FUNCTIONS */
 Pointer eval_fn(Pointer args, Pointer env);
-Pointer cons_fn(Pointer args);
-Pointer car_fn(Pointer args);
-Pointer cdr_fn(Pointer args);
+Pointer cons_fn(Pointer args, Pointer env);
+Pointer car_fn(Pointer args, Pointer env);
+Pointer cdr_fn(Pointer args, Pointer env);
 Pointer reduce_fn(Pointer args, Pointer env);
-Pointer add_fn(Pointer args);
-Pointer list_fn(Pointer args);
-Pointer sub_fn(Pointer args);
-Pointer mul_fn(Pointer args);
-Pointer div_fn(Pointer args);
-Pointer pow_fn(Pointer args);
-Pointer sqrt_fn(Pointer args);
-Pointer logand_fn(Pointer args);
-Pointer logor_fn(Pointer args);
-Pointer logxor_fn(Pointer args);
-Pointer lognot_fn(Pointer args);
+Pointer add_fn(Pointer args, Pointer env);
+Pointer list_fn(Pointer args, Pointer env);
+Pointer sub_fn(Pointer args, Pointer env);
+Pointer mul_fn(Pointer args, Pointer env);
+Pointer div_fn(Pointer args, Pointer env);
+Pointer pow_fn(Pointer args, Pointer env);
+Pointer sqrt_fn(Pointer args, Pointer env);
+Pointer logand_fn(Pointer args, Pointer env);
+Pointer logor_fn(Pointer args, Pointer env);
+Pointer logxor_fn(Pointer args, Pointer env);
+Pointer lognot_fn(Pointer args, Pointer env);
 Pointer if_fn(Pointer args, Pointer env);
 Pointer let_fn(Pointer args, Pointer env);
 Pointer quote_fn(Pointer args, Pointer env);
 Pointer and_fn(Pointer args, Pointer env);
 Pointer or_fn(Pointer args, Pointer env);
-Pointer not_fn(Pointer args);
+Pointer not_fn(Pointer args, Pointer env);
 Pointer def_fn(Pointer args, Pointer env);
 Pointer set_fn(Pointer args, Pointer env);
 Pointer fn_fn(Pointer args, Pointer env);
 Pointer peek_char_fn(Pointer args, Pointer env);
 Pointer read_char_fn(Pointer args, Pointer env);
 Pointer read_fn(Pointer args, Pointer env);
-Pointer set_reader_macro_fn(Pointer args);
+Pointer set_reader_macro_fn(Pointer args, Pointer env);
 Pointer read_char_macro_fn(Pointer args, Pointer env);
 Pointer read_list_macro_fn(Pointer args, Pointer env);
 Pointer read_right_paren_macro_fn(Pointer args, Pointer env);
diff --git a/implementations/c/src/reader.c b/implementations/c/src/reader.c
index 9937ee0..2c11ff2 100644
--- a/implementations/c/src/reader.c
+++ b/implementations/c/src/reader.c
@@ -107,15 +107,14 @@ Pointer read_fn(Pointer args, Pointer env) {
     : STREAM(streamPtr);
   double num = 0;
   Pointer macro;
-  int pos;
   Char c = peek_char(T, stream);
   if (feof(stream)) return NIL;
 
   macro = table_get(READTABLE, c);
   if (macro != UNDEFINED) {
     switch(memory_get(macro)->type) {
-    case SPECIAL_FORM:
-      return SPECIAL_FORM(macro)(LIST(streamPtr, character(get_utf8(stream))), env);
+    case NATIVE_FUNC:
+      return NATIVE_FUNC(macro)(LIST(streamPtr, character(get_utf8(stream))), env);
     case FUNC:
       return eval_fn(LIST(macro, streamPtr, character(get_utf8(stream))), env);
     default: break;
@@ -144,7 +143,8 @@ Pointer set_reader_macro(Pointer c, Pointer fn) {
   return T;
 }
 
-Pointer set_reader_macro_fn(Pointer args) {
+Pointer set_reader_macro_fn(Pointer args, Pointer env) {
+  (void) env;
   return set_reader_macro(CAR(args), CAR(CDR (args)));
 }
 
@@ -254,9 +254,9 @@ Pointer read_right_paren_macro_fn(Pointer args, Pointer env) {
 void reader_init(void) {
   buffer = string(NULL, 0);
   READTABLE = table(1);
-  READTABLE = table_set(READTABLE, '(', special_form(read_list_macro_fn));
-  READTABLE = table_set(READTABLE, ')', special_form(read_list_macro_fn));
-  READTABLE = table_set(READTABLE, '\\', special_form(read_char_macro_fn));
+  READTABLE = table_set(READTABLE, '(', native_func(read_list_macro_fn));
+  READTABLE = table_set(READTABLE, ')', native_func(read_list_macro_fn));
+  READTABLE = table_set(READTABLE, '\\', native_func(read_char_macro_fn));
   /* GLOBALS = table_set(GLOBALS, */
   /* 		      symbol("*standard-input*", sizeof("*standard-input*")), */
   /* 		      stream(stdin)); */
diff --git a/implementations/c/tests/check_ptlisp.log b/implementations/c/tests/check_ptlisp.log
index d4f6b29..933bc4d 100644
Binary files a/implementations/c/tests/check_ptlisp.log and b/implementations/c/tests/check_ptlisp.log differ
diff --git a/implementations/c/tests/cons-test.c b/implementations/c/tests/cons-test.c
index a42c87f..cd1bdad 100644
--- a/implementations/c/tests/cons-test.c
+++ b/implementations/c/tests/cons-test.c
@@ -9,7 +9,7 @@ START_TEST(cons_new_test) {
 END_TEST
 
 START_TEST(cons_car_nil_test) {
-  ck_assert_uint_eq(car_fn(NIL), NIL);
+  ck_assert_uint_eq(car_fn(NIL, NIL), NIL);
 }
 END_TEST
 
diff --git a/implementations/c/tests/lisp-test.c b/implementations/c/tests/lisp-test.c
index 5cecddb..fb32ab3 100644
--- a/implementations/c/tests/lisp-test.c
+++ b/implementations/c/tests/lisp-test.c
@@ -1,127 +1,127 @@
 #include "ptlisp-test.h"
 
 START_TEST(addition_zero_args_test) {
-  ck_assert_double_eq(NUMBER(add_fn(NIL)), 0);
+  ck_assert_double_eq(NUMBER(add_fn(NIL, NIL)), 0);
 }
 END_TEST
 
 START_TEST(addition_one_args_test) {
-  ck_assert_double_eq(NUMBER(add_fn(LIST(number(69)))), 69);
+  ck_assert_double_eq(NUMBER(add_fn(LIST(number(69)), NIL)), 69);
 }
 END_TEST
 
 START_TEST(addition_many_args_test) {
-  ck_assert_double_eq(NUMBER(add_fn(LIST(number(69), number(420)))), 489);
+  ck_assert_double_eq(NUMBER(add_fn(LIST(number(69), number(420)), NIL)), 489);
 }
 END_TEST
 
 START_TEST(substraction_zero_args_test) {
-  ck_assert_uint_eq(sub_fn(NIL), UNDEFINED);
+  ck_assert_uint_eq(sub_fn(NIL, NIL), UNDEFINED);
 }
 END_TEST
 
 START_TEST(substraction_one_args_test) {
-  ck_assert_double_eq(NUMBER(sub_fn(LIST(number(69)))), -69);
+  ck_assert_double_eq(NUMBER(sub_fn(LIST(number(69)), NIL)), -69);
 }
 END_TEST
 
 START_TEST(substraction_many_args_test) {
-  ck_assert_double_eq(NUMBER(sub_fn(LIST(number(69), number(420)))), -351);
+  ck_assert_double_eq(NUMBER(sub_fn(LIST(number(69), number(420)), NIL)), -351);
 }
 END_TEST
 
 START_TEST(multiplication_zero_args_test) {
-  ck_assert_double_eq(NUMBER(mul_fn(NIL)), 1);
+  ck_assert_double_eq(NUMBER(mul_fn(NIL, NIL)), 1);
 }
 END_TEST
 
 START_TEST(multiplication_one_args_test) {
-  ck_assert_double_eq(NUMBER(mul_fn(LIST(number(69)))), 69);
+  ck_assert_double_eq(NUMBER(mul_fn(LIST(number(69)), NIL)), 69);
 }
 END_TEST
 
 START_TEST(multiplication_many_args_test) {
-  ck_assert_double_eq(NUMBER(mul_fn(LIST(number(69), number(420)))), 28980);
+  ck_assert_double_eq(NUMBER(mul_fn(LIST(number(69), number(420)), NIL)), 28980);
 }
 END_TEST
 
 START_TEST(div_zero_args_test) {
-  ck_assert_double_eq(div_fn(NIL), UNDEFINED);
+  ck_assert_double_eq(div_fn(NIL, NIL), UNDEFINED);
 }
 END_TEST
 
 START_TEST(div_one_args_test) {
-  ck_assert_double_eq(NUMBER(div_fn(LIST(number(69)))), 1.0 / 69.0);
+  ck_assert_double_eq(NUMBER(div_fn(LIST(number(69)), NIL)), 1.0 / 69.0);
 }
 END_TEST
 
 START_TEST(div_many_args_test) {
-  ck_assert_double_eq(NUMBER(div_fn(LIST(number(69), number(420)))), 69.0 / 420.0);
+  ck_assert_double_eq(NUMBER(div_fn(LIST(number(69), number(420)), NIL)), 69.0 / 420.0);
 }
 END_TEST
 
 START_TEST(pow_test) {
-  ck_assert_double_eq(NUMBER(pow_fn(LIST(number(69), number(3)))), pow(69.0, 3.0));
+  ck_assert_double_eq(NUMBER(pow_fn(LIST(number(69), number(3)), NIL)), pow(69.0, 3.0));
 }
 END_TEST
 
 START_TEST(sqrt_test) {
-  ck_assert_double_eq(NUMBER(sqrt_fn(LIST(number(69)))), sqrt(69.0));
+  ck_assert_double_eq(NUMBER(sqrt_fn(LIST(number(69)), NIL)), sqrt(69.0));
 }
 END_TEST
 
 START_TEST(logand_zero_args_test) {
-  ck_assert_double_eq(NUMBER(logand_fn(NIL)), -1l);
+  ck_assert_double_eq(NUMBER(logand_fn(NIL, NIL)), -1l);
 }
 END_TEST
 
 START_TEST(logand_one_args_test) {
-  ck_assert_double_eq(NUMBER(logand_fn(LIST(number(69)))), -1l & 69l);
+  ck_assert_double_eq(NUMBER(logand_fn(LIST(number(69)), NIL)), -1l & 69l);
 }
 END_TEST
 
 START_TEST(logand_many_args_test) {
-  ck_assert_double_eq(NUMBER(logand_fn(LIST(number(69), number(420)))), 69l & 420l);
+  ck_assert_double_eq(NUMBER(logand_fn(LIST(number(69), number(420)), NIL)), 69l & 420l);
 }
 END_TEST
 
 START_TEST(logor_zero_args_test) {
-  ck_assert_double_eq(NUMBER(logor_fn(NIL)), 0l);
+  ck_assert_double_eq(NUMBER(logor_fn(NIL, NIL)), 0l);
 }
 END_TEST
 
 START_TEST(logor_one_args_test) {
-  ck_assert_double_eq(NUMBER(logor_fn(LIST(number(69)))), 0l | 69l);
+  ck_assert_double_eq(NUMBER(logor_fn(LIST(number(69)), NIL)), 0l | 69l);
 }
 END_TEST
 
 START_TEST(logor_many_args_test) {
-  ck_assert_double_eq(NUMBER(logor_fn(LIST(number(69), number(420)))), 69l | 420l);
+  ck_assert_double_eq(NUMBER(logor_fn(LIST(number(69), number(420)), NIL)), 69l | 420l);
 }
 END_TEST
 
 START_TEST(logxor_zero_args_test) {
-  ck_assert_double_eq(NUMBER(logxor_fn(NIL)), 0l);
+  ck_assert_double_eq(NUMBER(logxor_fn(NIL, NIL)), 0l);
 }
 END_TEST
 
 START_TEST(logxor_one_args_test) {
-  ck_assert_double_eq(NUMBER(logxor_fn(LIST(number(69)))), 0l ^ 69l);
+  ck_assert_double_eq(NUMBER(logxor_fn(LIST(number(69)), NIL)), 0l ^ 69l);
 }
 END_TEST
 
 START_TEST(logxor_many_args_test) {
-  ck_assert_double_eq(NUMBER(logxor_fn(LIST(number(69), number(420)))), 69l ^ 420l);
+  ck_assert_double_eq(NUMBER(logxor_fn(LIST(number(69), number(420)), NIL)), 69l ^ 420l);
 }
 END_TEST
 
 START_TEST(lognot_zero_args_test) {
-  ck_assert_double_eq(lognot_fn(NIL), UNDEFINED);
+  ck_assert_double_eq(lognot_fn(NIL, NIL), UNDEFINED);
 }
 END_TEST
 
 START_TEST(lognot_one_args_test) {
-  ck_assert_double_eq(NUMBER(lognot_fn(LIST(number(69)))), ~69l);
+  ck_assert_double_eq(NUMBER(lognot_fn(LIST(number(69)), NIL)), ~69l);
 }
 END_TEST
 
@@ -179,8 +179,8 @@ START_TEST(or_test) {
 END_TEST
 
 START_TEST(not_test) {
-  ck_assert_double_eq(not_fn(LIST(NIL)), T);
-  ck_assert_uint_eq(not_fn(LIST(T)), NIL);
+  ck_assert_double_eq(not_fn(LIST(NIL), NIL), T);
+  ck_assert_uint_eq(not_fn(LIST(T), NIL), NIL);
 }
 END_TEST
 
diff --git a/implementations/c/tests/reader-test.c b/implementations/c/tests/reader-test.c
index c5df745..d0d5745 100644
--- a/implementations/c/tests/reader-test.c
+++ b/implementations/c/tests/reader-test.c
@@ -56,7 +56,7 @@ START_TEST(set_reader_macro_test) {
 } END_TEST
 
 START_TEST(set_reader_macro_fn_test) {
-  ck_assert_uint_eq(set_reader_macro_fn(LIST(69, 420)), T);
+  ck_assert_uint_eq(set_reader_macro_fn(LIST(69, 420), NIL), T);
   /* ck_assert_uint_eq(table_get(READTABLE, 69), 420); */
 } END_TEST