1 files changed, 18 insertions, 0 deletions
diff --git a/transfer/lib/nat.tr b/transfer/lib/nat.tr
new file mode 100644
index 000000000..c529e5238
--- /dev/null
+++ b/transfer/lib/nat.tr
@@ -0,0 +1,18 @@
+data Nat : Type where
+	Zero : Nat
+  	Succ : (n:Nat) -> Nat
+
+plus : Nat -> Nat -> Nat
+plus Zero y = y
+plus (Succ x) y = Succ (plus x y)
+
+pred : Nat -> Nat
+pred Zero = Zero
+pred (Succ n) = n
+
+natToInt : Nat -> Int
+natToInt Zero = 0
+natToInt (Succ n) = 1 + natToInt n
+
+intToNat : Int -> Nat
+intToNat n = if n == 0 then Zero else Succ (intToNat (n-1))