Haskell has a `let ... in` syntax. Quoting from (1): quicksort1 :: (Ord a) => [a] -> [a] quicksort1 [] = [] quicksort1 (x:xs) = let smallerSo

Haskell has a `let ... in` syntax. Quoting from (1): quicksort1 :: (Ord a) => [a] -> [a] quicksort1 [] = [] quicksort1 (x:xs) = let smallerSorted = quicksort1 [a | a <- xs, a <= x] biggerSorted = quicksort1 [a | a <- xs, a > x] in smallerSorted ++ [x] ++ biggerSorted 1: http://learnyouahaskell.com/recursion http://learnyouahaskell.com/recursion