haskell

module A where

a :: Int -> Int
a 0 = 0
a n = x where
  x :: Int
  x = n + 3

  y :: Int
  y = x+1

sublist :: Int -> Int -> [a] -> [a]
sublist from to ls = take size (drop from ls)
    where size = to - from + 1

index :: Int -> Int -> [[a]] -> a
index i j mx = mx !! i !! j

concat :: [[a]] - [a]
concat [] = []
concat (x:ls) = x ++ concat ls

splice :: Int -> [a] -> [[a]]
splice _ [] = []
splice n ls = take n ls: splice n (drop n ls)