input: 
  from typing import Tuple
  
  def calculate_sum_using_lambda(a: int, b: int) -> Tuple[int, str]:
      """ Calculate the sum of two variables using a lambda function and return the
      result along with the lambda expression as a string.
      >>> calculate_sum_using_lambda(3, 4)
      (7, '(lambda a, b: a + b)')
      """
  
output:     sum_func = lambda a, b: a + b
      return sum_func(a, b), '(lambda a, b: a + b)'