input: Write a function to take a list of integers and return a list of booleans where each element is True if the corresponding element in the input list is a prime number, and False otherwise. The function should be named `check_lst` and should include a helper function `is_prime` to determine if a number is prime.
  assert check_lst([7, 8, 12, 19, 22, 23]) == [True, False, False, True, False, True]
  assert check_lst([2, 3, 5, 7, 10, 11]) == [True, True, True, True, False, True]
  assert check_lst([]) == []
  assert check_lst([1, 4, 6, 8, 9, 10]) == [False, False, False, False, False, False]
  assert check_lst([23, 29, 31, 37, 41, 43]) == [True, True, True, True, True, True]
output: def check_lst(lst):
      def is_prime(n):
          if n <= 1:
              return False
          for i in range(2, int(n**0.5) + 1):
              if n % i == 0:
                  return False
          return True
      return [is_prime(x) for x in lst]