content: --------------------------------------------------------------------------------
  -- MIT License
  --
  -- Copyright (C) 2023 Duck McSouls <quacksouls [AT] gmail [DOT] com>
  --
  -- Permission is hereby granted, free of charge, to any person obtaining a copy
  -- of this software and associated documentation files (the "Software"), to deal
  -- in the Software without restriction, including without limitation the rights
  -- to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  -- copies of the Software, and to permit persons to whom the Software is
  -- furnished to do so, subject to the following conditions:
  --
  -- The above copyright notice and this permission notice shall be included in
  -- all copies or substantial portions of the Software.
  --
  -- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  -- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  -- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  -- AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  -- LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  -- OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  -- SOFTWARE.
  --------------------------------------------------------------------------------
  
  import Control.Monad
  import Data.Foldable
  import System.Random.Stateful
  import Text.Printf
  
  -- | The least element in a list.
  least :: [Int] -> Int
  least [] = error "Must be non-empty list"
  least [x] = x
  least (x:xs) =
      if x > head xs
          then least xs
          else least $ x : tail xs
  
  -- | The least element in a list, using a fold operation.
  leastf :: [Int] -> Int
  leastf []     = error "Must be non-empty list"
  leastf [x]    = x
  leastf (x:xs) = foldr (\y acc -> myMin y acc) x xs
  
  -- | The minimum of two integers.
  myMin :: Int -> Int -> Int
  myMin x y
      | x < y = x
      | otherwise = y
  
  -- | Generate random integers.
  randint :: Int -> IO [Int]
  randint n = replicateM n (uniformRM (1, 1000) globalStdGen :: IO Int)
  
  -- | The minimum of a list.
  main = do
      kk <- randint 1
      let k = head kk
      for_ [1 .. k] $ \_ -> do
          ell <- randint 10
          let low = least ell
          let result = low == minimum ell && low == leastf ell
          if result
              then printf "%s -> %d: %s\n" (show ell) low $ show result
              else error "False"
  