main = for 0 10000

for x n = case n of 
    0 => 0
    n => for ((revRange 10000)) (n - 1)

data List (a) where
    Nil : List (a)
    Cons : a -> List (a) -> List (a)

-- create a list of x to 0
revRange x = case x of 
    0 => Cons x Nil
    x => Cons x (revRange (x - 1))

sum xs = case xs of 
    Cons x ys => x + sum ys
    Nil => 0