input: Write a function to explain how recursion can be used to solve a given problem in Python. The function should describe the technique of defining a problem in terms of itself, breaking it down into smaller problems, and how the results from smaller problems can be combined to solve the original problem.
  
  def explain_recursion():
      """
      This function explains the concept of recursion and how it can be used to solve problems in Python.
      
      Explanation:
      - Recursion involves defining a problem in terms of itself.
      - The problem is solved by breaking it down into smaller problems until a base case is reached.
      - The results from smaller problems are combined to solve the original problem.
      - In Python, a recursive function is one that calls itself.
      """
      explanation = (
          "Recursion is a powerful technique for solving problems. "
          "It involves defining a problem in terms of itself. A recursion problem "
          "is solved by breaking it down into smaller problems, until the problem "
          "is small enough to be solved directly. The result from a smaller problem "
          "can then be combined with the result from the larger problem, until the "
          "original problem is solved. In Python, a recursive function is one that "
          "calls itself."
      )
      return explanation
  
  assert explain_recursion()=="Recursion is a powerful technique for solving problems. It involves defining a problem in terms of itself. A recursion problem is solved by breaking it down into smaller problems, until the problem is small enough to be solved directly. The result from a smaller problem can then be combined with the result from the larger problem, until the original problem is solved. In Python, a recursive function is one that calls itself."
output: def explain_recursion():
      explanation = (
          "Recursion is a powerful technique for solving problems. "
          "It involves defining a problem in terms of itself. A recursion problem "
          "is solved by breaking it down into smaller problems, until the problem "
          "is small enough to be solved directly. The result from a smaller problem "
          "can then be combined with the result from the larger problem, until the "
          "original problem is solved. In Python, a recursive function is one that "
          "calls itself."
      )
      return explanation