div x y = case (compare x y) of LT -> Zero
                                EQ -> Succ Zero
                                GT ->  Succ (div (sub x y) y)
div x y = case (compare x y) of LT -> Zero
                                EQ -> Succ Zero
                                GT ->  Succ (div (sub x y) y)
div x y = case (compare x y) of LT -> Zero
                                EQ -> Succ Zero
                                GT ->  Succ (div (sub x y) y)