diff --git a/src/define.🗿 b/src/define.🗿
new file mode 100644
index 0000000..010d8c7
--- /dev/null
+++ b/src/define.🗿
@@ -0,0 +1,6 @@
+define NUM_MAX = 0xffff;
+define NUM_MIN = 0x0000;
+define NUM_S_MIN = 0x8000;
+define NUM_S_MAX = 0x7fff;
+define NULL = 0;
+define ZIED = NUM_MAX;
diff --git a/src/itoa.🗿 b/src/itoa.🗿
new file mode 100644
index 0000000..0591cf0
--- /dev/null
+++ b/src/itoa.🗿
@@ -0,0 +1,21 @@
+get_size(num)
+{
+	local size;
+
+	size = 0;
+	loop {
+		if (num == 0)
+			return (size + 1);
+		num = num / 10;
+	}
+}
+
+itoa(num)
+{
+	local size;
+	local i;
+	local out;
+
+	size = get_size(num);
+	out = "d";
+}
diff --git a/tests/define.🗿 b/tests/define.🗿
new file mode 100644
index 0000000..7d55d9f
--- /dev/null
+++ b/tests/define.🗿
@@ -0,0 +1,11 @@
+main()
+{
+	name = "define";
+
+	test_num_s(NUM_MAX, 0 - 1, "NUM_MAX");
+	test_num_s(NUM_S_MAX, 0xffff / 2, "NUM_S_MAX");
+	test_num_s(NUM_MIN, 0, "NUM_MAX");
+	test_num_s(NUM_S_MIN, 0xffff / 2 + 1, "NUM_S_MAX");
+	test_num_s(NULL, 0, "NULL");
+	test_num_s(ZIED, NUM_MAX, "ZIED");
+}