content: import Numeric.Natural
  
  
  logistic :: Num a => a -> a -> Natural -> a
  logistic rate start = f
    where
      f 0 = start
      f n = rate * f (n - 1) * (1 - f (n - 1))
  
  logistic0 :: Fractional a => Natural -> a
  logistic0 = logistic 3.741 0.00079
  
  ex1 :: Natural
  ex1 = 100
  
  
  ex20 :: Fractional a => [a]
  ex20 = [1, logistic0 ex1, 3]
  
  ex21 :: Fractional a => a
  ex21 = head ex20
  
  ex22 :: Fractional a => a
  ex22 = ex20 !! 2
  
  ex23 :: Fractional a => [a]
  ex23 = drop 2 ex20
  
  ex24 :: Fractional a => [a]
  ex24 = tail ex20
  
  
  ex31 :: Natural -> Bool
  ex31 x = x < 7 || logistic0 (ex1 + x) > 2
  
  ex32 :: Natural -> Bool
  ex32 x = logistic0 (ex1 + x) > 2 || x < 7
  ex33 :: Bool
  ex33 = ex31 5
  
  ex34 :: Bool
  ex34 = ex31 7
  
  ex35 :: Bool
  ex35 = ex32 5
  
  ex36 :: Bool
  ex36 = ex32 7
  
  
  semn :: [Integer] -> String
  semn = f
     where
       f [] = ""
       f (h:t) = if h >= -9 && h<0 then
                     '-':(f t)
                 else if h == 0 then
                     '0':(f t)
                 else if h>0 && h<=9 then
                     '+':(f t)
                 else
                     (f t)
  
  semnFold :: [Integer] -> String
  semnFold = foldr op unit
     where
       unit = ""
       op = (\a b -> if a==0 then '0':b else if a>=(-9) && a<0 then '-':b else if a>0 && a<=9 then '+':b else b)
       
       
       
  matrice :: Num a => [[a]]
  matrice = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]     
  
  
  corect :: [[a]] -> Bool 
  corect = f
     where
       f [] = True
       f [a,b] = (length a) == (length b) 
       f (a:b:t) = if (length a) == (length b) then f (b:t) else False
  
  el :: [[a]] -> Int -> Int -> a
  
  el' [a] _ = a
  el' (h:t) p = if p==0 then h else el' t (p-1)
  
  el'' :: [a] -> Int -> a
  el'' [a] _ = a
  el'' (h:t) p = if p==0 then h else el'' t (p-1)
  
  --el l p1 p2 = el'' (el' l p1) p2
  el matrix i j = (matrix !! i) !! j
  
  transforma :: [[a]] -> [(a, Int, Int)]
  transforma  = undefined
  
  main = undefined
  