input: Write a function to explain how to use recursion to solve a given problem in Python. The function should detail the concept of recursion, how a problem is broken down, and how the results from smaller problems are combined to solve the original problem.
  assert 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."
  ]
  assert 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."
output: def recursion_explanation():
      return [
          "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."
      ]