input: Write a function to check if an element exists within a given list of integers. If the element exists in the list, return True; otherwise, return False. If the list is empty, return False.
  def element_exists(elem, list_int):
    return elem in list_int
  
  assert element_exists(3, [1, 2, 3, 4, 5])==True
  assert element_exists(6, [1, 2, 3, 4, 5])==False
  assert element_exists(0, [])==False
output: def element_exists(elem, list_int):
    return elem in list_int