[exercise] 8.1

Author: Dev-XYS

chapter08-Declaring-types-and-classes/1.hs

@@ -0,0 +1,10 @@
+data Nat = Zero | Succ Nat
+ deriving Show
+
+add :: Nat -> Nat -> Nat
+add Zero n = n
+add (Succ m) n = Succ (add m n)
+
+mult :: Nat -> Nat -> Nat
+mult Zero n = Zero
+mult (Succ m) n = add n (mult m n)