content: --------------------------------------------------------------------------------
  -- MIT License
  --
  -- Copyright (C) 2024 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
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  -- copies of the Software, and to permit persons to whom the Software is
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  --
  -- The above copyright notice and this permission notice shall be included in
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  -- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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  --------------------------------------------------------------------------------
  
  import Text.Printf
  
  -- | An implementation of the function "and" without using the operator "&&".
  -- Boolean "and" is also known as conjunction.
  conj :: [Bool] -> Bool
  conj []         = True
  conj [x]        = x
  conj (False:xs) = False
  conj (True:xs)  = conj xs
  
  -- | An implementation of the function "and" without using the operator "&&".
  main = do
      let a = []
      let b = [True]
      let c = [False]
      let d = b ++ c
      let e = c ++ d
      let f = b ++ b ++ c
      let g = [even x | x <- [1 .. 10]]
      let h = [even x | x <- [2,4 .. 10]]
      let i = [even x | x <- [1,3 .. 10]]
      let testa = conj a == and a
      let testb = conj b == and b
      let testc = conj c == and c
      let testd = conj d == and d
      let teste = conj e == and e
      let testf = conj f == and f
      let testg = conj g == and g
      let testh = conj h == and h
      let testi = conj i == and i
      printf "[] -> %s, %s\n" (show . conj $ a) $ show testa
      printf "%s -> %s, %s\n" (show b) (show . conj $ b) $ show testb
      printf "%s -> %s, %s\n" (show c) (show . conj $ c) $ show testc
      printf "%s -> %s, %s\n" (show d) (show . conj $ d) $ show testd
      printf "%s -> %s, %s\n" (show e) (show . conj $ e) $ show teste
      printf "%s -> %s, %s\n" (show f) (show . conj $ f) $ show testf
      printf "%s -> %s, %s\n" (show g) (show . conj $ g) $ show testg
      printf "%s -> %s, %s\n" (show h) (show . conj $ h) $ show testh
      printf "%s -> %s, %s\n" (show i) (show . conj $ i) $ show testi
  