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